/usr/share/doc/zsh-common/html/Expansion.html is in zsh-doc 5.3.1-4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 | <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- Created by GNU Texinfo 6.3, http://www.gnu.org/software/texinfo/ -->
<head>
<title>zsh: 14 Expansion</title>
<meta name="description" content="zsh: 14 Expansion">
<meta name="keywords" content="zsh: 14 Expansion">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="texi2any">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
-->
</style>
</head>
<body lang="en">
<a name="Expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="Prompt-Expansion.html#Prompt-Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="Prompt-Expansion.html#Conditional-Substrings-in-Prompts" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#History-Expansion" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Expansion-1"></a>
<h1 class="chapter">14 Expansion</h1>
<a name="index-expansion"></a>
<p>The following types of expansions are performed in the indicated order in
five steps:
</p>
<dl compact="compact">
<dt><em>History Expansion</em></dt>
<dd><p>This is performed only in interactive shells.
</p>
</dd>
<dt><em>Alias Expansion</em></dt>
<dd><p>Aliases are expanded immediately before the command line is parsed as
explained
in <a href="Shell-Grammar.html#Aliasing">Aliasing</a>.
</p>
</dd>
<dt><em>Process Substitution</em></dt>
<dt><em>Parameter Expansion</em></dt>
<dt><em>Command Substitution</em></dt>
<dt><em>Arithmetic Expansion</em></dt>
<dt><em>Brace Expansion</em></dt>
<dd><p>These five are performed in one step in left-to-right fashion. After
these expansions, all unquoted occurrences of the characters ‘<tt>\</tt>’,
‘<tt>'</tt>’ and ‘<tt>"</tt>’ are removed.
</p>
</dd>
<dt><em>Filename Expansion</em></dt>
<dd><p>If the <tt>SH_FILE_EXPANSION</tt> option is set, the order of expansion is
modified for compatibility with <cite>sh</cite> and <cite>ksh</cite>. In that case
<em>filename expansion</em> is performed immediately after <em>alias expansion</em>,
preceding the set of five expansions mentioned above.
</p>
<a name="index-globbing"></a>
</dd>
<dt><em>Filename Generation</em></dt>
<dd><p>This expansion, commonly referred to as <cite>globbing</cite>, is always done last.
</p>
</dd>
</dl>
<p>The following sections explain the types of expansion in detail.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top"><a href="#History-Expansion">14.1 History Expansion</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Process-Substitution">14.2 Process Substitution</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Parameter-Expansion">14.3 Parameter Expansion</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Command-Substitution">14.4 Command Substitution</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Arithmetic-Expansion">14.5 Arithmetic Expansion</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Brace-Expansion">14.6 Brace Expansion</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Filename-Expansion">14.7 Filename Expansion</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Filename-Generation">14.8 Filename Generation</a></td><td> </td><td align="left" valign="top">
</td></tr>
</table>
<hr>
<a name="History-Expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Overview" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="History-Expansion-1"></a>
<h2 class="section">14.1 History Expansion</h2>
<p><a name="index-history"></a>
<a name="index-history-expansion"></a>
<a name="index-expansion_002c-history"></a>
History expansion allows you to use words from previous command
lines in the command line you are typing. This simplifies spelling
corrections and the repetition of complicated commands or arguments.
</p>
<p><a name="index-HISTSIZE_002c-use-of"></a>
Immediately before execution, each command is saved in the history list,
the size of which is controlled by the <tt>HISTSIZE</tt> parameter. The one
most recent command is always retained in any case. Each saved command in
the history list is called a history <em>event</em> and is assigned a number,
beginning with 1 (one) when the shell starts up. The history number that
you may see in your prompt (see
<a href="Prompt-Expansion.html#Prompt-Expansion">Prompt Expansion</a>) is the number that is to be assigned to the <em>next</em> command.
</p>
<table class="menu" border="0" cellspacing="0">
<tr><td align="left" valign="top"><a href="#Overview">14.1.1 Overview</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Event-Designators">14.1.2 Event Designators</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Word-Designators">14.1.3 Word Designators</a></td><td> </td><td align="left" valign="top">
</td></tr>
<tr><td align="left" valign="top"><a href="#Modifiers">14.1.4 Modifiers</a></td><td> </td><td align="left" valign="top">
</td></tr>
</table>
<hr>
<a name="Overview"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#History-Expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#History-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Event-Designators" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Overview-1"></a>
<h3 class="subsection">14.1.1 Overview</h3>
<p><a name="index-histchars_002c-use-of-1"></a>
A history expansion begins with the first character of the <tt>histchars</tt>
parameter, which is ‘<tt>!</tt>’ by default, and may occur anywhere on the
command line; history expansions do not nest. The ‘<tt>!</tt>’ can be escaped
with ‘<tt>\</tt>’ or can be enclosed between a pair of single quotes (<tt>''</tt>)
to suppress its special meaning. Double quotes will <em>not</em> work for
this. Following this history character is an optional event designator
(<a href="#Event-Designators">Event Designators</a>) and then an optional word
designator (<a href="#Word-Designators">Word Designators</a>); if neither of these designators is
present, no history expansion occurs.
</p>
<p>Input lines containing history expansions are echoed after being expanded,
but before any other expansions take place and before the command is
executed. It is this expanded form that is recorded as the history event
for later references.
</p>
<p>By default, a history reference with no event designator refers to the
same event as any preceding history reference on that command line; if it
is the only history reference in a command, it refers to the previous
command.
<a name="index-CSH_005fJUNKIE_005fHISTORY_002c-use-of"></a>
However, if the option <tt>CSH_JUNKIE_HISTORY</tt> is set, then every history
reference with no event specification <em>always</em> refers to the previous
command.
</p>
<p>For example, ‘<tt>!</tt>’ is the event designator for the previous command, so
‘<tt>!!:1</tt>’ always refers to the first word of the previous command, and
‘<tt>!!$</tt>’ always refers to the last word of the previous command. With
<tt>CSH_JUNKIE_HISTORY</tt> set, then ‘<tt>!:1</tt>’ and ‘<tt>!$</tt>’ function in the
same manner as ‘<tt>!!:1</tt>’ and ‘<tt>!!$</tt>’, respectively. Conversely, if
<tt>CSH_JUNKIE_HISTORY</tt> is unset, then ‘<tt>!:1</tt>’ and ‘<tt>!$</tt>’ refer to the
first and last words, respectively, of the same event referenced by the
nearest other history reference preceding them on the current command
line, or to the previous command if there is no preceding reference.
</p>
<p>The character sequence ‘<tt>^</tt><var>foo</var><tt>^</tt><var>bar</var>’ (where ‘<tt>^</tt>’ is
actually the second character of the <tt>histchars</tt> parameter)
repeats the last command, replacing the string <var>foo</var> with <var>bar</var>.
More precisely, the sequence ‘<tt>^</tt><var>foo</var><tt>^</tt><var>bar</var><tt>^</tt>’ is
synonymous with ‘<tt>!!:s</tt><tt>^</tt><var>foo</var><tt>^</tt><var>bar</var><tt>^</tt>’, hence other
modifiers (see <a href="#Modifiers">Modifiers</a>) may follow the final ‘<tt>^</tt>’.
In particular, ‘<tt>^</tt><var>foo</var><tt>^</tt><var>bar</var><tt>^:G</tt>’ performs a global
substitution.
</p>
<p>If the shell encounters the character sequence ‘<tt>!"</tt>’
in the input, the history mechanism is temporarily disabled until
the current list (see
<a href="Shell-Grammar.html#Shell-Grammar">Shell Grammar</a>) is fully parsed. The ‘<tt>!"</tt>’ is removed from the input, and any
subsequent ‘<tt>!</tt>’ characters have no special significance.
</p>
<p><a name="index-fc_002c-use-of"></a>
A less convenient but more comprehensible form of command history support
is provided by the <tt>fc</tt> builtin.
</p><hr>
<a name="Event-Designators"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Overview" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#History-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Word-Designators" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Event-Designators-1"></a>
<h3 class="subsection">14.1.2 Event Designators</h3>
<p><a name="index-history-event-designators"></a>
<a name="index-event-designators_002c-history"></a>
An event designator is a reference to a command-line entry in the history
list. In the list below, remember that the initial <tt>`!'</tt> in each item
may be changed to another character by setting the <tt>histchars</tt>
parameter.
</p>
<dl compact="compact">
<dt><tt>!</tt></dt>
<dd><p>Start a history expansion, except when followed by a blank, newline,
‘<tt>=</tt>’ or ‘<tt>(</tt>’. If followed immediately by a word designator
(<a href="#Word-Designators">Word Designators</a>), this forms a history reference
with no event designator (<a href="#Overview">Overview</a>).
</p>
</dd>
<dt><tt>!!</tt></dt>
<dd><p>Refer to the previous command.
By itself, this expansion
repeats the previous command.
</p>
</dd>
<dt><tt>!</tt><var>n</var></dt>
<dd><p>Refer to command-line <var>n</var>.
</p>
</dd>
<dt><tt>!-</tt><var>n</var></dt>
<dd><p>Refer to the current command-line minus <var>n</var>.
</p>
</dd>
<dt><tt>!</tt><var>str</var></dt>
<dd><p>Refer to the most recent command starting with <var>str</var>.
</p>
</dd>
<dt><tt>!?</tt><var>str</var>[<tt>?</tt>]</dt>
<dd><p>Refer to the most recent command containing <var>str</var>. The trailing
‘<tt>?</tt>’ is necessary if this reference is to be followed by a modifier or
followed by any text that is not to be considered part of <var>str</var>.
</p>
</dd>
<dt><tt>!#</tt></dt>
<dd><p>Refer to the current command line typed in so far. The line is
treated as if it were complete up to and including the word before the
one with the ‘<tt>!#</tt>’ reference.
</p>
</dd>
<dt><tt>!{</tt>...<tt>}</tt></dt>
<dd><p>Insulate a history reference from adjacent characters (if necessary).
</p>
</dd>
</dl>
<hr>
<a name="Word-Designators"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Event-Designators" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#History-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Modifiers" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Word-Designators-1"></a>
<h3 class="subsection">14.1.3 Word Designators</h3>
<p><a name="index-history-word-designators"></a>
<a name="index-word-designators_002c-history"></a>
A word designator indicates which word or words of a given command line are
to be included in a history reference. A ‘<tt>:</tt>’ usually
separates the event specification from the word designator.
It may be omitted only if the word designator begins with a
‘<tt>^</tt>’, ‘<tt>$</tt>’, ‘<tt>*</tt>’, ‘<tt>-</tt>’ or ‘<tt>%</tt>’.
Word designators include:
</p>
<dl compact="compact">
<dt><tt>0</tt></dt>
<dd><p>The first input word (command).
</p></dd>
<dt><var>n</var></dt>
<dd><p>The <var>n</var>th argument.
</p></dd>
<dt><tt>^</tt></dt>
<dd><p>The first argument. That is, <tt>1</tt>.
</p></dd>
<dt><tt>$</tt></dt>
<dd><p>The last argument.
</p></dd>
<dt><tt>%</tt></dt>
<dd><p>The word matched by (the most recent) <tt>?</tt><var>str</var> search.
</p></dd>
<dt><var>x</var><tt>-</tt><var>y</var></dt>
<dd><p>A range of words; <var>x</var> defaults to <tt>0</tt>.
</p></dd>
<dt><tt>*</tt></dt>
<dd><p>All the arguments, or a null value if there are none.
</p></dd>
<dt><var>x</var><tt>*</tt></dt>
<dd><p>Abbreviates ‘<var>x</var><tt>-$</tt>’.
</p></dd>
<dt><var>x</var><tt>-</tt></dt>
<dd><p>Like ‘<var>x</var><tt>*</tt>’ but omitting word <tt>$</tt>.
</p></dd>
</dl>
<p>Note that a ‘<tt>%</tt>’ word designator works only when used in one of
‘<tt>!%</tt>’, ‘<tt>!:%</tt>’ or ‘<tt>!?</tt><var>str</var><tt>?:%</tt>’, and only when used after a
<tt>!?</tt> expansion (possibly in an earlier command). Anything else results
in an error, although the error may not be the most obvious one.
</p><hr>
<a name="Modifiers"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Word-Designators" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#History-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Process-Substitution" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Modifiers-1"></a>
<h3 class="subsection">14.1.4 Modifiers</h3>
<p><a name="index-modifiers"></a>
<a name="index-colon-modifiers"></a>
<a name="index-history-modifiers"></a>
<a name="index-globbing-modifiers"></a>
<a name="index-parameter-modifiers"></a>
After the optional word designator, you can add
a sequence of one or more of the following modifiers,
each preceded by a ‘<tt>:</tt>’. These modifiers also work on the result
of <em>filename generation</em> and <em>parameter expansion</em>, except where
noted.
</p>
<dl compact="compact">
<dt><tt>a</tt></dt>
<dd><p>Turn a file name into an absolute path: prepends the current directory,
if necessary; remove ‘<tt>.</tt>’ path segments; and remove ‘<tt>..</tt>’ path segments
and the segments that immediately precede them.
</p>
<p>This transformation is agnostic about what is in the filesystem, i.e. is
on the logical, not the physical directory. It takes place in the same
manner as when changing directories when neither of the options
<tt>CHASE_DOTS</tt> or <tt>CHASE_LINKS</tt> is set. For example,
‘<tt>/before/here/../after</tt>’ is always transformed to
‘<tt>/before/after</tt>’, regardless of whether ‘<tt>/before/here</tt>’ exists or what
kind of object (dir, file, symlink, etc.) it is.
</p>
</dd>
<dt><tt>A</tt></dt>
<dd><p>Turn a file name into an absolute path as the ‘<tt>a</tt>’ modifier does, and
<em>then</em> pass the result through the <tt>realpath(3)</tt> library
function to resolve symbolic links.
</p>
<p>Note: on systems that do not have a <tt>realpath(3)</tt> library
function, symbolic links are not resolved, so on those systems ‘<tt>a</tt>’ and
‘<tt>A</tt>’ are equivalent.
</p>
<p>Note: <tt>foo:A</tt> and <tt>realpath(foo)</tt> are different on some inputs.
For <tt>realpath(foo)</tt> semantics, see the ‘<tt>P</tt>‘ modifier.
</p>
</dd>
<dt><tt>c</tt></dt>
<dd><p>Resolve a command name into an absolute path by searching the command
path given by the <tt>PATH</tt> variable. This does not work for commands
containing directory parts. Note also that this does not usually work as
a glob qualifier unless a file of the same name is found in the
current directory.
</p>
</dd>
<dt><tt>e</tt></dt>
<dd><p>Remove all but the part of the filename extension following the ‘<tt>.</tt>’;
see the definition of the filename extension in the description of the
<tt>r</tt> modifier below. Note that according to that definition the result
will be empty if the string ends with a ‘<tt>.</tt>’.
</p>
</dd>
<dt><tt>h</tt></dt>
<dd><p>Remove a trailing pathname component, leaving the head. This works
like ‘<tt>dirname</tt>’.
</p>
</dd>
<dt><tt>l</tt></dt>
<dd><p>Convert the words to all lowercase.
</p>
</dd>
<dt><tt>p</tt></dt>
<dd><p>Print the new command but do not execute it. Only works with history
expansion.
</p>
</dd>
<dt><tt>P</tt></dt>
<dd><p>Turn a file name into an absolute path, like <tt>realpath(3)</tt>.
The resulting path will be absolute, have neither ‘<tt>.</tt>’ nor ‘<tt>..</tt>’ components,
and refer to the same directory entry as the input filename.
</p>
<p>Unlike <tt>realpath(3)</tt>, non-existent trailing components are
permitted and preserved.
</p>
</dd>
<dt><tt>q</tt></dt>
<dd><p>Quote the substituted words, escaping further substitutions. Works
with history expansion and parameter expansion, though for parameters
it is only useful if the resulting text is to be re-evaluated such as
by <tt>eval</tt>.
</p>
</dd>
<dt><tt>Q</tt></dt>
<dd><p>Remove one level of quotes from the substituted words.
</p>
</dd>
<dt><tt>r</tt></dt>
<dd><p>Remove a filename extension leaving the root name. Strings with no
filename extension are not altered. A filename
extension is a ‘<tt>.</tt>’ followed by any number of characters (including
zero) that are neither ‘<tt>.</tt>’ nor ‘<tt>/</tt>’ and that continue to the end
of the string. For example, the extension of
‘<tt>foo.orig.c</tt>’ is ‘<tt>.c</tt>’, and ‘<tt>dir.c/foo</tt>’ has no extension.
</p>
</dd>
<dt><tt>s/</tt><var>l</var><tt>/</tt><var>r</var>[<tt>/</tt>]</dt>
<dd><p>Substitute <var>r</var> for <var>l</var> as described below.
The substitution is done only for the
first string that matches <var>l</var>. For arrays and for filename
generation, this applies to each word of the expanded text. See
below for further notes on substitutions.
</p>
<p>The forms ‘<tt>gs/</tt><var>l</var><tt>/</tt><var>r</var>’ and ‘<tt>s/</tt><var>l</var><tt>/</tt><var>r</var><tt>/:G</tt>’
perform global substitution, i.e. substitute every occurrence of <var>r</var>
for <var>l</var>. Note that the <tt>g</tt> or <tt>:G</tt> must appear in exactly the
position shown.
</p>
<p>See further notes on this form of substitution below.
</p>
</dd>
<dt><tt>&</tt></dt>
<dd><p>Repeat the previous <tt>s</tt> substitution. Like <tt>s</tt>, may be preceded
immediately by a <tt>g</tt>. In parameter expansion the <tt>&</tt> must appear
inside braces, and in filename generation it must be quoted with a
backslash.
</p>
</dd>
<dt><tt>t</tt></dt>
<dd><p>Remove all leading pathname components, leaving the tail. This works
like ‘<tt>basename</tt>’.
</p>
</dd>
<dt><tt>u</tt></dt>
<dd><p>Convert the words to all uppercase.
</p>
</dd>
<dt><tt>x</tt></dt>
<dd><p>Like <tt>q</tt>, but break into words at whitespace. Does not work with
parameter expansion.
</p>
</dd>
</dl>
<p>The <tt>s/</tt><var>l</var><tt>/</tt><var>r</var><tt>/</tt> substitution works as follows. By
default the left-hand side of substitutions are not patterns, but
character strings. Any character can be used as the delimiter in place
of ‘<tt>/</tt>’. A backslash quotes the delimiter character. The character
‘<tt>&</tt>’, in the right-hand-side <var>r</var>, is replaced by the text from the
left-hand-side <var>l</var>. The ‘<tt>&</tt>’ can be quoted with a backslash. A
null <var>l</var> uses the previous string either from the previous <var>l</var> or
from the contextual scan string <var>s</var> from ‘<tt>!?</tt><var>s</var>’. You can
omit the rightmost delimiter if a newline immediately follows <var>r</var>;
the rightmost ‘<tt>?</tt>’ in a context scan can similarly be omitted. Note
the same record of the last <var>l</var> and <var>r</var> is maintained across all
forms of expansion.
</p>
<p>Note that if a ‘<tt>&</tt>’ is used within glob qualifiers an extra backslash
is needed as a <tt>&</tt> is a special character in this case.
</p>
<p>Also note that the order of expansions affects the interpretation of
<var>l</var> and <var>r</var>. When used in a history expansion, which occurs before
any other expansions, <var>l</var> and <var>r</var> are treated as literal strings
(except as explained for <tt>HIST_SUBST_PATTERN</tt> below). When used in
parameter expansion, the replacement of <var>r</var> into the parameter’s value
is done first, and then any additional process, parameter, command,
arithmetic, or brace references are applied, which may evaluate those
substitutions and expansions more than once if <var>l</var> appears more than
once in the starting value. When used in a glob qualifier, any
substitutions or expansions are performed once at the time the qualifier
is parsed, even before the ‘<tt>:s</tt>’ expression itself is divided into
<var>l</var> and <var>r</var> sides.
</p>
<p>If the option <tt>HIST_SUBST_PATTERN</tt> is set, <var>l</var> is treated as
a pattern of the usual form described in
<a href="#Filename-Generation">Filename Generation</a>. This can be used in
all the places where modifiers are available; note, however, that
in globbing qualifiers parameter substitution has already taken place,
so parameters in the replacement string should be quoted to ensure
they are replaced at the correct time.
Note also that complicated patterns used in globbing qualifiers may
need the extended glob qualifier notation
<tt>(#q:s/</tt><var>...</var><tt>/</tt><var>...</var><tt>/)</tt> in order for the
shell to recognize the expression as a glob qualifier. Further,
note that bad patterns in the substitution are not subject to
the <tt>NO_BAD_PATTERN</tt> option so will cause an error.
</p>
<p>When <tt>HIST_SUBST_PATTERN</tt> is set, <var>l</var> may start with a <tt>#</tt>
to indicate that the pattern must match at the start of the string
to be substituted, and a <tt>%</tt> may appear at the start or after an <tt>#</tt>
to indicate that the pattern must match at the end of the string
to be substituted. The <tt>%</tt> or <tt>#</tt> may be quoted with two
backslashes.
</p>
<p>For example, the following piece of filename generation code
with the <tt>EXTENDED_GLOB</tt> option:
</p>
<div class="example">
<pre class="example">print *.c(#q:s/#%(#b)s(*).c/'S${match[1]}.C'/)
</pre></div>
<p>takes the expansion of <tt>*.c</tt> and applies the glob qualifiers in the
<tt>(#q</tt><var>...</var><tt>)</tt> expression, which consists of a substitution
modifier anchored to the start and end of each word (<tt>#%</tt>). This
turns on backreferences (<tt>(#b)</tt>), so that the parenthesised
subexpression is available in the replacement string as <tt>${match[1]}</tt>.
The replacement string is quoted so that the parameter is not substituted
before the start of filename generation.
</p>
<p>The following <tt>f</tt>, <tt>F</tt>, <tt>w</tt> and <tt>W</tt> modifiers work only with
parameter expansion and filename generation. They are listed here to
provide a single point of reference for all modifiers.
</p>
<dl compact="compact">
<dt><tt>f</tt></dt>
<dd><p>Repeats the immediately (without a colon) following modifier until the
resulting word doesn’t change any more.
</p>
</dd>
<dt><tt>F:</tt><var>expr</var><tt>:</tt></dt>
<dd><p>Like <tt>f</tt>, but repeats only <var>n</var> times if the expression
<var>expr</var> evaluates to <var>n</var>. Any character can be used instead of
the ‘<tt>:</tt>’; if ‘<tt>(</tt>’, ‘<tt>[</tt>’, or ‘<tt>{</tt>’
is used as the opening delimiter,
the closing delimiter should be ’<tt>)</tt>’, ‘<tt>]</tt>’, or ‘<tt>}</tt>’,
respectively.
</p>
</dd>
<dt><tt>w</tt></dt>
<dd><p>Makes the immediately following modifier work on each word in the
string.
</p>
</dd>
<dt><tt>W:</tt><var>sep</var><tt>:</tt></dt>
<dd><p>Like <tt>w</tt> but words are considered to be the parts of the string
that are separated by <var>sep</var>. Any character can be used instead of
the ‘<tt>:</tt>’; opening parentheses are handled specially, see above.
</p>
</dd>
</dl>
<hr>
<a name="Process-Substitution"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Modifiers" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Process-Substitution-1"></a>
<h2 class="section">14.2 Process Substitution</h2>
<p><a name="index-process-substitution"></a>
<a name="index-substitution_002c-process"></a>
Each part of a command argument that takes the form
‘<tt><(</tt><var>list</var><tt>)</tt>’,
‘<tt>>(</tt><var>list</var><tt>)</tt>’ or
‘<tt>=(</tt><var>list</var><tt>)</tt>’
is subject to process substitution. The expression may be preceded
or followed by other strings except that, to prevent clashes with
commonly occurring strings and patterns, the last
form must occur at the start of a command argument, and the forms
are only expanded when first parsing command or assignment arguments.
Process substitutions may be used following redirection operators; in this
case, the substitution must appear with no trailing string.
</p>
<p>Note that ‘<tt><<(</tt><var>list</var><tt>)</tt>’ is not a special syntax; it
is equivalent to ‘<tt>< <(</tt><var>list</var><tt>)</tt>’, redirecting
standard input from the result of process substitution. Hence all
the following documentation applies. The second form (with the space)
is recommended for clarity.
</p>
<p>In the case of the <tt><</tt> or <tt>></tt> forms, the shell runs the commands in
<var>list</var> as a subprocess of the job executing the shell command line.
If the system supports the <tt>/dev/fd</tt>
mechanism, the command argument is the name of the device file
corresponding to a file descriptor; otherwise, if the system supports named
pipes (FIFOs), the command argument will be a named pipe. If the form with
<tt>></tt> is selected then writing on this special file will provide input for
<var>list</var>. If <tt><</tt> is used, then the file passed as an argument will
be connected to the output of the <var>list</var> process. For example,
</p>
<div class="example">
<pre class="example"><tt>paste <(cut -f1</tt> <var>file1</var><tt>) <(cut -f3</tt> <var>file2</var><tt>) |
tee >(</tt><var>process1</var><tt>) >(</tt><var>process2</var><tt>) >/dev/null</tt>
</pre></div>
<p>cuts fields 1 and 3 from the files <var>file1</var> and <var>file2</var> respectively,
pastes the results together, and sends it to the processes
<var>process1</var> and <var>process2</var>.
</p>
<p>If <tt>=(</tt><var>...</var><tt>)</tt> is used instead of
<tt><(</tt><var>...</var><tt>)</tt>,
then the file passed as an argument will be the name
of a temporary file containing the output of the <var>list</var>
process. This may be used instead of the <tt><</tt>
form for a program that expects to lseek (see man page lseek(2))
on the input file.
</p>
<p>There is an optimisation for substitutions of the form
<tt>=(<<<</tt><var>arg</var><tt>)</tt>, where <var>arg</var> is a single-word argument
to the here-string redirection <tt><<<</tt>. This form produces a file name
containing the value of <var>arg</var> after any substitutions have been
performed. This is handled entirely within the current shell. This is
effectively the reverse of the special form <tt>$(<</tt><var>arg</var><tt>)</tt>
which treats <var>arg</var> as a file name and replaces it with the file’s
contents.
</p>
<p>The <tt>=</tt> form is useful as both the <tt>/dev/fd</tt> and the named pipe
implementation of <tt><(</tt><var>...</var><tt>)</tt> have drawbacks. In
the former case, some programmes may automatically close the file
descriptor in question before examining the file on the command line,
particularly if this is necessary for security reasons such as when the
programme is running setuid. In the second case, if the
programme does not actually open the file, the subshell attempting to read
from or write to the pipe will (in a typical implementation, different
operating systems may have different behaviour) block for ever and have to
be killed explicitly. In both cases, the shell actually supplies the
information using a pipe, so that programmes that expect to lseek
(see man page lseek(2)) on the file will not work.
</p>
<p>Also note that the previous example can be more compactly and
efficiently written (provided the <tt>MULTIOS</tt> option is set) as:
</p>
<div class="example">
<pre class="example"><tt>paste <(cut -f1</tt> <var>file1</var><tt>) <(cut -f3</tt> <var>file2</var><tt>)</tt> <tt>> >(</tt><var>process1</var><tt>) > >(</tt><var>process2</var><tt>)</tt>
</pre></div>
<p>The shell uses pipes instead of FIFOs to implement the latter
two process substitutions in the above example.
</p>
<p>There is an additional problem with <tt>>(</tt><var>process</var><tt>)</tt>; when
this is attached to an external command, the parent shell does not wait
for <var>process</var> to finish and hence an immediately following command
cannot rely on the results being complete. The problem and solution are
the same as described in the section <em>MULTIOS</em> in
<a href="Redirection.html#Redirection">Redirection</a>. Hence in a simplified
version of the example above:
</p>
<div class="example">
<pre class="example"><tt>paste <(cut -f1</tt> <var>file1</var><tt>) <(cut -f3</tt> <var>file2</var><tt>)</tt> <tt>> >(</tt><var>process</var><tt>)</tt>
</pre></div>
<p>(note that no <tt>MULTIOS</tt> are involved), <var>process</var> will be run
asynchronously as far as the parent shell is concerned. The workaround is:
</p>
<div class="example">
<pre class="example"><tt>{ paste <(cut -f1</tt> <var>file1</var><tt>) <(cut -f3</tt> <var>file2</var><tt>) }</tt> <tt>> >(</tt><var>process</var><tt>)</tt>
</pre></div>
<p>The extra processes here are
spawned from the parent shell which will wait for their completion.
</p>
<p>Another problem arises any time a job with a substitution that requires
a temporary file is disowned by the shell, including the case where
‘<tt>&!</tt>’ or ‘<tt>&|</tt>’ appears at the end of a command containing a
substitution. In that case the temporary file will not be cleaned up as
the shell no longer has any memory of the job. A workaround is to use
a subshell, for example,
</p>
<div class="example">
<pre class="example">(mycmd =(myoutput)) &!
</pre></div>
<p>as the forked subshell will wait for the command to finish then remove
the temporary file.
</p>
<p>A general workaround to ensure a process substitution endures for
an appropriate length of time is to pass it as a parameter to
an anonymous shell function (a piece of shell code that is run
immediately with function scope). For example, this code:
</p>
<div class="example">
<pre class="example">() {
print File $1:
cat $1
} =(print This be the verse)
</pre></div>
<p>outputs something resembling the following
</p>
<div class="example">
<pre class="example">File /tmp/zsh6nU0kS:
This be the verse
</pre></div>
<p>The temporary file created by the process substitution will be deleted
when the function exits.
</p>
<hr>
<a name="Parameter-Expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Process-Substitution" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion-Flags" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Parameter-Expansion-1"></a>
<h2 class="section">14.3 Parameter Expansion</h2>
<p><a name="index-parameter-expansion"></a>
<a name="index-expansion_002c-parameter"></a>
The character ‘<tt>$</tt>’ is used to introduce parameter expansions.
See
<a href="Parameters.html#Parameters">Parameters</a>
for a description of parameters, including arrays, associative arrays,
and subscript notation to access individual array elements.
</p>
<p>Note in particular the fact that words of unquoted parameters are not
automatically split on whitespace unless the option <tt>SH_WORD_SPLIT</tt> is
set; see references to this option below for more details. This is an
important difference from other shells.
</p>
<p>In the expansions discussed below that require a pattern, the form of
the pattern is the same as that used for filename generation;
see <a href="#Filename-Generation">Filename Generation</a>. Note that these patterns, along with
the replacement text of any substitutions, are themselves subject to
parameter expansion, command substitution, and arithmetic expansion.
In addition to the following operations, the colon modifiers described in
<a href="#Modifiers">Modifiers</a> in <a href="#History-Expansion">History Expansion</a> can be
applied: for example, <tt>${i:s/foo/bar/}</tt> performs string
substitution on the expansion of parameter <tt>$i</tt>.
</p>
<p>In the following descriptions, ‘word’ refers to a single word
substituted on the command line, not necessarily a space delimited word.
With default options, after the assignments:
</p>
<div class="example">
<pre class="example">array=("first word" "second word")
scalar="only word"
</pre></div>
<p>then <tt>$array</tt> substitutes two words, ‘<tt>first word</tt>’ and ‘<tt>second
word</tt>’, and <tt>$scalar</tt> substitutes a single word ‘<tt>only word</tt>’. This
may be modified by explicit or implicit word-splitting, however. The
full rules are complicated and are noted at the end.
</p>
<dl compact="compact">
<dt><tt>${</tt><var>name</var><tt>}</tt></dt>
<dd><p>The value, if any, of the parameter <var>name</var> is substituted.
The braces are required if the expansion is to be followed by
a letter, digit, or underscore that is not to be interpreted
as part of <var>name</var>. In addition, more complicated forms of substitution
usually require the braces to be present; exceptions, which only apply if
the option <tt>KSH_ARRAYS</tt> is not set, are a single subscript or any colon
modifiers appearing after the name, or any of the characters ‘<tt>^</tt>’,
‘<tt>=</tt>’, ‘<tt>~</tt>’, ‘<tt>#</tt>’ or ‘<tt>+</tt>’ appearing before the name, all of
which work with or without braces.
</p>
<p>If <var>name</var> is an array parameter, and the <tt>KSH_ARRAYS</tt> option is not
set, then the value of each
element of <var>name</var> is substituted, one element per word. Otherwise, the
expansion results in one word only; with <tt>KSH_ARRAYS</tt>, this is the first
element of an array. No field splitting is done on the result unless the
<tt>SH_WORD_SPLIT</tt> option is set.
See also the flags <tt>=</tt> and <tt>s:</tt><var>string</var><tt>:</tt>.
</p>
</dd>
<dt><tt>${+</tt><var>name</var><tt>}</tt></dt>
<dd><p>If <var>name</var> is the name of a set parameter ‘<tt>1</tt>’ is substituted,
otherwise ‘<tt>0</tt>’ is substituted.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>-</tt><var>word</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:-</tt><var>word</var><tt>}</tt></dt>
<dd><p>If <var>name</var> is set, or in the second form is non-null, then substitute
its value; otherwise substitute <var>word</var>. In the second form <var>name</var>
may be omitted, in which case <var>word</var> is always substituted.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>+</tt><var>word</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:+</tt><var>word</var><tt>}</tt></dt>
<dd><p>If <var>name</var> is set, or in the second form is non-null, then substitute
<var>word</var>; otherwise substitute nothing.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>=</tt><var>word</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:=</tt><var>word</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>::=</tt><var>word</var><tt>}</tt></dt>
<dd><p>In the first form, if <var>name</var> is unset then set it to <var>word</var>; in the
second form, if <var>name</var> is unset or null then set it to <var>word</var>; and
in the third form, unconditionally set <var>name</var> to <var>word</var>. In all
forms, the value of the parameter is then substituted.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>?</tt><var>word</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:?</tt><var>word</var><tt>}</tt></dt>
<dd><p>In the first form, if <var>name</var> is set, or in the second form if <var>name</var>
is both set and non-null, then substitute its value; otherwise, print
<var>word</var> and exit from the shell. Interactive shells instead return to
the prompt. If <var>word</var> is omitted, then a standard message is printed.
</p>
</dd>
</dl>
<p>In any of the above expressions that test a variable and substitute an
alternate <var>word</var>, note that you can use standard shell quoting in the
<var>word</var> value to selectively override the splitting done by the
<tt>SH_WORD_SPLIT</tt> option and the <tt>=</tt> flag, but not splitting by the
<tt>s:</tt><var>string</var><tt>:</tt> flag.
</p>
<p>In the following expressions, when <var>name</var> is an array and
the substitution is not quoted, or if the ‘<tt>(@)</tt>’ flag or the
<var>name</var><tt>[@]</tt> syntax is used, matching and replacement is
performed on each array element separately.
</p>
<dl compact="compact">
<dt><tt>${</tt><var>name</var><tt>#</tt><var>pattern</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>##</tt><var>pattern</var><tt>}</tt></dt>
<dd><p>If the <var>pattern</var> matches the beginning of the value of
<var>name</var>, then substitute the value of <var>name</var> with
the matched portion deleted; otherwise, just
substitute the value of <var>name</var>. In the first
form, the smallest matching pattern is preferred;
in the second form, the largest matching pattern is
preferred.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>%</tt><var>pattern</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>%%</tt><var>pattern</var><tt>}</tt></dt>
<dd><p>If the <var>pattern</var> matches the end of the value of
<var>name</var>, then substitute the value of <var>name</var> with
the matched portion deleted; otherwise, just
substitute the value of <var>name</var>. In the first
form, the smallest matching pattern is preferred;
in the second form, the largest matching pattern is
preferred.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>:#</tt><var>pattern</var><tt>}</tt></dt>
<dd><p>If the <var>pattern</var> matches the value of <var>name</var>, then substitute
the empty string; otherwise, just substitute the value of <var>name</var>.
If <var>name</var> is an array
the matching array elements are removed (use the ‘<tt>(M)</tt>’ flag to
remove the non-matched elements).
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>:|</tt><var>arrayname</var><tt>}</tt></dt>
<dd><p>If <var>arrayname</var> is the name (N.B., not contents) of an array
variable, then any elements contained in <var>arrayname</var> are removed
from the substitution of <var>name</var>. If the substitution is scalar,
either because <var>name</var> is a scalar variable or the expression is
quoted, the elements of <var>arrayname</var> are instead tested against the
entire expression.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>:*</tt><var>arrayname</var><tt>}</tt></dt>
<dd><p>Similar to the preceding substitution, but in the opposite sense,
so that entries present in both the original substitution and as
elements of <var>arrayname</var> are retained and others removed.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>:^</tt><var>arrayname</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:^^</tt><var>arrayname</var><tt>}</tt></dt>
<dd><p>Zips two arrays, such that the output array is twice as long as the
shortest (longest for ‘<tt>:^^</tt>’) of <tt>name</tt> and <tt>arrayname</tt>, with
the elements alternatingly being picked from them. For ‘<tt>:^</tt>’, if one
of the input arrays is longer, the output will stop when the end of the
shorter array is reached. Thus,
</p>
<div class="example">
<pre class="example">a=(1 2 3 4); b=(a b); print ${a:^b}
</pre></div>
<p>will output ‘<tt>1 a 2 b</tt>’. For ‘<tt>:^^</tt>’, then the input is repeated
until all of the longer array has been used up and the above will output
‘<tt>1 a 2 b 3 a 4 b</tt>’.
</p>
<p>Either or both inputs may be a scalar, they will be treated as an array
of length 1 with the scalar as the only element. If either array is empty,
the other array is output with no extra elements inserted.
</p>
<p>Currently the following code will output ‘<tt>a b</tt>’ and ‘<tt>1</tt>’ as two separate
elements, which can be unexpected. The second print provides a workaround which
should continue to work if this is changed.
</p>
<div class="example">
<pre class="example">a=(a b); b=(1 2); print -l "${a:^b}"; print -l "${${a:^b}}"
</pre></div>
</dd>
<dt><tt>${</tt><var>name</var><tt>:</tt><var>offset</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:</tt><var>offset</var><tt>:</tt><var>length</var><tt>}</tt></dt>
<dd><p>This syntax gives effects similar to parameter subscripting
in the form <tt>$</tt><var>name</var><tt>[</tt><var>start</var><tt>,</tt><var>end</var><tt>]</tt>, but is
compatible with other shells; note that both <var>offset</var> and <var>length</var>
are interpreted differently from the components of a subscript.
</p>
<p>If <var>offset</var> is non-negative, then if the variable <var>name</var> is a
scalar substitute the contents starting <var>offset</var> characters from the
first character of the string, and if <var>name</var> is an array substitute
elements starting <var>offset</var> elements from the first element. If
<var>length</var> is given, substitute that many characters or elements,
otherwise the entire rest of the scalar or array.
</p>
<p>A positive <var>offset</var> is always treated as the offset of a character or
element in <var>name</var> from the first character or element of the array
(this is different from native zsh subscript notation). Hence 0
refers to the first character or element regardless of the setting of
the option <tt>KSH_ARRAYS</tt>.
</p>
<p>A negative offset counts backwards from the end of the scalar or array,
so that -1 corresponds to the last character or element, and so on.
</p>
<p>When positive, <var>length</var> counts from the <var>offset</var> position
toward the end of the scalar or array. When negative, <var>length</var>
counts back from the end. If this results in a position smaller
than <var>offset</var>, a diagnostic is printed and nothing is substituted.
</p>
<p>The option <tt>MULTIBYTE</tt> is obeyed, i.e. the offset and length
count multibyte characters where appropriate.
</p>
<p><var>offset</var> and <var>length</var> undergo the same set of shell substitutions
as for scalar assignment; in addition, they are then subject to arithmetic
evaluation. Hence, for example
</p>
<div class="example">
<pre class="example">print ${foo:3}
print ${foo: 1 + 2}
print ${foo:$(( 1 + 2))}
print ${foo:$(echo 1 + 2)}
</pre></div>
<p>all have the same effect, extracting the string starting at the fourth
character of <tt>$foo</tt> if the substitution would otherwise return a scalar,
or the array starting at the fourth element if <tt>$foo</tt> would return an
array. Note that with the option <tt>KSH_ARRAYS</tt> <tt>$foo</tt> always returns
a scalar (regardless of the use of the offset syntax) and a form
such as <tt>${foo[*]:3}</tt> is required to extract elements of an array named
<tt>foo</tt>.
</p>
<p>If <var>offset</var> is negative, the <tt>-</tt> may not appear immediately
after the <tt>:</tt> as this indicates the
<tt>${</tt><var>name</var><tt>:-</tt><var>word</var><tt>}</tt> form of substitution. Instead, a space
may be inserted before the <tt>-</tt>. Furthermore, neither <var>offset</var> nor
<var>length</var> may begin with an alphabetic character or <tt>&</tt> as these are
used to indicate history-style modifiers. To substitute a value from a
variable, the recommended approach is to precede it with a <tt>$</tt> as this
signifies the intention (parameter substitution can easily be rendered
unreadable); however, as arithmetic substitution is performed, the
expression <tt>${var: offs}</tt> does work, retrieving the offset from
<tt>$offs</tt>.
</p>
<p>For further compatibility with other shells there is a special case
for array offset 0. This usually accesses the
first element of the array. However, if the substitution refers to the
positional parameter array, e.g. <tt>$@</tt> or <tt>$*</tt>, then offset 0
instead refers to <tt>$0</tt>, offset 1 refers to <tt>$1</tt>, and so on. In
other words, the positional parameter array is effectively extended by
prepending <tt>$0</tt>. Hence <tt>${*:0:1}</tt> substitutes <tt>$0</tt> and
<tt>${*:1:1}</tt> substitutes <tt>$1</tt>.
</p>
</dd>
<dt><tt>${</tt><var>name</var><tt>/</tt><var>pattern</var><tt>/</tt><var>repl</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>//</tt><var>pattern</var><tt>/</tt><var>repl</var><tt>}</tt></dt>
<dt><tt>${</tt><var>name</var><tt>:/</tt><var>pattern</var><tt>/</tt><var>repl</var><tt>}</tt></dt>
<dd><p>Replace the longest possible match of <var>pattern</var> in the expansion of
parameter <var>name</var> by string <var>repl</var>. The first form
replaces just the first occurrence, the second form all occurrences,
and the third form replaces only if <var>pattern</var> matches the entire string.
Both <var>pattern</var> and <var>repl</var> are subject to double-quoted substitution,
so that expressions like <tt>${name/$opat/$npat}</tt> will work, but obey the
usual rule that pattern characters in <tt>$opat</tt> are not treated specially
unless either the option <tt>GLOB_SUBST</tt> is set, or <tt>$opat</tt> is instead
substituted as <tt>${~opat}</tt>.
</p>
<p>The <var>pattern</var> may begin with a ‘<tt>#</tt>’, in which case the
<var>pattern</var> must match at the start of the string, or ‘<tt>%</tt>’, in
which case it must match at the end of the string, or ‘<tt>#%</tt>’ in which
case the <var>pattern</var> must match the entire string. The <var>repl</var> may
be an empty string, in which case the final ‘<tt>/</tt>’ may also be omitted.
To quote the final ‘<tt>/</tt>’ in other cases it should be preceded by a
single backslash; this is not necessary if the
‘<tt>/</tt>’ occurs inside a substituted parameter. Note also that the ‘<tt>#</tt>’,
‘<tt>%</tt>’ and ‘<tt>#%</tt> are not active if they occur inside a substituted
parameter, even at the start.
</p>
<p>If, after quoting rules apply, <tt>${</tt><var>name</var><tt>}</tt> expands to an array,
the replacements act on each element individually. Note also the
effect of the <tt>I</tt> and <tt>S</tt> parameter expansion flags below; however,
the flags <tt>M</tt>, <tt>R</tt>, <tt>B</tt>, <tt>E</tt> and <tt>N</tt> are not useful.
</p>
<p>For example,
</p>
<div class="example">
<pre class="example">foo="twinkle twinkle little star" sub="t*e" rep="spy"
print ${foo//${~sub}/$rep}
print ${(S)foo//${~sub}/$rep}
</pre></div>
<p>Here, the ‘<tt>~</tt>’ ensures that the text of <tt>$sub</tt> is treated as a
pattern rather than a plain string. In the first case, the longest
match for <tt>t*e</tt> is substituted and the result is ‘<tt>spy star</tt>’,
while in the second case, the shortest matches are taken and the
result is ‘<tt>spy spy lispy star</tt>’.
</p>
</dd>
<dt><tt>${#</tt><var>spec</var><tt>}</tt></dt>
<dd><p>If <var>spec</var> is one of the above substitutions, substitute
the length in characters of the result instead of
the result itself. If <var>spec</var> is an array expression,
substitute the number of elements of the result.
This has the side-effect that joining is skipped even in quoted
forms, which may affect other sub-expressions in <var>spec</var>.
Note that ‘<tt>^</tt>’, ‘<tt>=</tt>’, and ‘<tt>~</tt>’, below, must appear
to the left of ‘<tt>#</tt>’ when these forms are combined.
</p>
<p>If the option <tt>POSIX_IDENTIFIERS</tt> is not set, and <var>spec</var> is a
simple name, then the braces are optional; this is true even
for special parameters so e.g. <tt>$#-</tt> and <tt>$#*</tt> take the length
of the string <tt>$-</tt> and the array <tt>$*</tt> respectively. If
<tt>POSIX_IDENTIFIERS</tt> is set, then braces are required for
the <tt>#</tt> to be treated in this fashion.
</p>
</dd>
<dt><tt>${^</tt><var>spec</var><tt>}</tt></dt>
<dd><a name="index-RC_005fEXPAND_005fPARAM_002c-toggle"></a>
<a name="index-array-expansion-style_002c-rc"></a>
<a name="index-rc_002c-array-expansion-style"></a>
<p>Turn on the <tt>RC_EXPAND_PARAM</tt> option for the
evaluation of <var>spec</var>; if the ‘<tt>^</tt>’ is doubled, turn it off.
When this option is set, array expansions of the form
<var>foo</var><tt>${</tt><var>xx</var><tt>}</tt><var>bar</var>,
where the parameter <var>xx</var>
is set to <tt>(</tt><var>a b c</var><tt>)</tt>, are substituted with
‘<var>fooabar foobbar foocbar</var>’ instead of the default
‘<var>fooa b cbar</var>’. Note that an empty array will therefore cause
all arguments to be removed.
</p>
<p>Internally, each such expansion is converted into the
equivalent list for brace expansion. E.g., <tt>${^var}</tt> becomes
<tt>{$var[1],$var[2],</tt>...<tt>}</tt>, and is processed as described in
<a href="#Brace-Expansion">Brace Expansion</a> below.
If word splitting is also in effect the
<tt>$var[</tt><var>N</var><tt>]</tt> may themselves be split into different list
elements.
</p>
</dd>
<dt><tt>${=</tt><var>spec</var><tt>}</tt></dt>
<dd><a name="index-SH_005fWORD_005fSPLIT_002c-toggle"></a>
<a name="index-field-splitting_002c-sh-style_002c-parameter"></a>
<a name="index-sh_002c-field-splitting-style_002c-parameter"></a>
<p>Perform word splitting using the rules for <tt>SH_WORD_SPLIT</tt> during the
evaluation of <var>spec</var>, but regardless of whether the parameter appears in
double quotes; if the ‘<tt>=</tt>’ is doubled, turn it off.
<a name="index-IFS_002c-use-of"></a>
This forces parameter expansions to be split into
separate words before substitution, using <tt>IFS</tt> as a delimiter.
This is done by default in most other shells.
</p>
<p>Note that splitting is applied to <var>word</var> in the assignment forms
of <var>spec</var> <em>before</em> the assignment to <var>name</var> is performed.
This affects the result of array assignments with the <tt>A</tt> flag.
</p>
</dd>
<dt><tt>${~</tt><var>spec</var><tt>}</tt></dt>
<dd><a name="index-GLOB_005fSUBST_002c-toggle"></a>
<p>Turn on the <tt>GLOB_SUBST</tt> option for the evaluation of
<var>spec</var>; if the ‘<tt>~</tt>’ is doubled, turn it off. When this option is
set, the string resulting from the expansion will be interpreted as a
pattern anywhere that is possible, such as in filename expansion and
filename generation and pattern-matching contexts like the right
hand side of the ‘<tt>=</tt>’ and ‘<tt>!=</tt>’ operators in conditions.
</p>
<p>In nested substitutions, note that the effect of the <tt>~</tt> applies to the
result of the current level of substitution. A surrounding pattern
operation on the result may cancel it. Hence, for example, if the
parameter <tt>foo</tt> is set to <tt>*</tt>, <tt>${~foo//\*/*.c}</tt> is substituted by
the pattern <tt>*.c</tt>, which may be expanded by filename generation, but
<tt>${${~foo}//\*/*.c}</tt> substitutes to the string <tt>*.c</tt>, which will not
be further expanded.
</p>
</dd>
</dl>
<p>If a <tt>${</tt>...<tt>}</tt> type parameter expression or a
<tt>$(</tt>...<tt>)</tt> type command substitution is used in place of
<var>name</var> above, it is expanded first and the result is used as if
it were the value of <var>name</var>. Thus it is
possible to perform nested operations: <tt>${${foo#head}%tail}</tt>
substitutes the value of <tt>$foo</tt> with both ‘<tt>head</tt>’ and ‘<tt>tail</tt>’
deleted. The form with <tt>$(</tt>...<tt>)</tt> is often useful in
combination with the flags described next; see the examples below.
Each <var>name</var> or nested <tt>${</tt>...<tt>}</tt> in a parameter expansion may
also be followed by a subscript expression as described in
<a href="Parameters.html#Array-Parameters">Array Parameters</a>.
</p>
<p>Note that double quotes may appear around nested expressions, in which
case only the part inside is treated as quoted; for example,
<tt>${(f)"$(foo)"}</tt> quotes the result of <tt>$(foo)</tt>, but the flag ‘<tt>(f)</tt>’
(see below) is applied using the rules for unquoted expansions. Note
further that quotes are themselves nested in this context; for example, in
<tt>"${(@f)"$(foo)"}"</tt>, there are two sets of quotes, one surrounding the
whole expression, the other (redundant) surrounding the <tt>$(foo)</tt> as
before.
</p>
<hr>
<a name="Parameter-Expansion-Flags"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Rules" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.3.1 Parameter Expansion Flags</h3>
<p><a name="index-parameter-expansion-flags"></a>
<a name="index-flags_002c-parameter-expansion"></a>
<a name="index-substitution_002c-parameter_002c-flags"></a>
If the opening brace is directly followed by an opening parenthesis,
the string up to the matching closing parenthesis will be taken as a
list of flags. In cases where repeating a flag is meaningful, the
repetitions need not be consecutive; for example, ‘(<tt>q%q%q</tt>)’
means the same thing as the more readable ‘(<tt>%%qqq</tt>)’. The
following flags are supported:
</p>
<dl compact="compact">
<dt><tt>#</tt></dt>
<dd><p>Evaluate the resulting words as numeric expressions and output the
characters corresponding to the resulting integer. Note that this form is
entirely distinct from use of the <tt>#</tt> without parentheses.
</p>
<p>If the <tt>MULTIBYTE</tt> option is set and the number is greater than 127
(i.e. not an ASCII character) it is treated as a Unicode character.
</p>
</dd>
<dt><tt>%</tt></dt>
<dd><p>Expand all <tt>%</tt> escapes in the resulting words in the same way as in
prompts (see
<a href="Prompt-Expansion.html#Prompt-Expansion">Prompt Expansion</a>). If this flag is given twice,
full prompt expansion is done on the resulting words, depending on the
setting of the <tt>PROMPT_PERCENT</tt>, <tt>PROMPT_SUBST</tt> and <tt>PROMPT_BANG</tt>
options.
</p>
</dd>
<dt><tt>@</tt></dt>
<dd><p>In double quotes, array elements are put into separate words.
E.g., ‘<tt>"${(@)foo}"</tt>’ is equivalent to ‘<tt>"${foo[@]}"</tt>’ and
‘<tt>"${(@)foo[1,2]}"</tt>’ is the same as ‘<tt>"$foo[1]" "$foo[2]"</tt>’.
This is distinct from <em>field splitting</em> by the <tt>f</tt>, <tt>s</tt>
or <tt>z</tt> flags, which still applies within each array element.
</p>
</dd>
<dt><tt>A</tt></dt>
<dd><p>Create an array parameter with ‘<tt>${</tt>...<tt>=</tt>...<tt>}</tt>’,
‘<tt>${</tt>...<tt>:=</tt>...<tt>}</tt>’ or ‘<tt>${</tt>...<tt>::=</tt>...<tt>}</tt>’.
If this flag is repeated (as in ‘<tt>AA</tt>’), create an associative
array parameter. Assignment is made before sorting or padding;
if field splitting is active, the <var>word</var> part is split before
assignment. The <var>name</var> part may be a subscripted range for
ordinary arrays; the <var>word</var> part <em>must</em> be converted to
an array, for example by using ‘<tt>${(AA)=</tt><var>name</var><tt>=</tt>...<tt>}</tt>’
to activate field splitting, when creating an associative array.
</p>
</dd>
<dt><tt>a</tt></dt>
<dd><p>Sort in array index order; when combined with ‘<tt>O</tt>’ sort in reverse
array index order. Note that ‘<tt>a</tt>’ is therefore equivalent to the
default but ‘<tt>Oa</tt>’ is useful for obtaining an array’s elements in reverse
order.
</p>
</dd>
<dt><tt>b</tt></dt>
<dd><p>Quote with backslashes only characters that are special to pattern
matching. This is useful when the contents of the variable are to be
tested using <tt>GLOB_SUBST</tt>, including the <tt>${~</tt><var>...</var><tt>}</tt> switch.
</p>
<p>Quoting using one of the <tt>q</tt> family of flags does not work
for this purpose since quotes are not stripped from non-pattern
characters by <tt>GLOB_SUBST</tt>. In other words,
</p>
<div class="example">
<pre class="example">pattern=${(q)str}
[[ $str = ${~pattern} ]]
</pre></div>
<p>works if <tt>$str</tt> is ‘<tt>a*b</tt>’ but not if it is ‘<tt>a b</tt>’, whereas
</p>
<div class="example">
<pre class="example">pattern=${(b)str}
[[ $str = ${~pattern} ]]
</pre></div>
<p>is always true for any possible value of <tt>$str</tt>.
</p>
</dd>
<dt><tt>c</tt></dt>
<dd><p>With <tt>${#</tt><var>name</var><tt>}</tt>, count the total number of characters in an array,
as if the elements were concatenated with spaces between them. This is not
a true join of the array, so other expressions used with this flag may have
an effect on the elements of the array before it is counted.
</p>
</dd>
<dt><tt>C</tt></dt>
<dd><p>Capitalize the resulting words. ‘Words’ in this case refers to sequences
of alphanumeric characters separated by non-alphanumerics, <em>not</em> to words
that result from field splitting.
</p>
</dd>
<dt><tt>D</tt></dt>
<dd><p>Assume the string or array elements contain directories and attempt
to substitute the leading part of these by names. The remainder of
the path (the whole of it if the leading part was not substituted)
is then quoted so that the whole string can be used as a shell
argument. This is the reverse of ‘<tt>~</tt>’ substitution: see
<a href="#Filename-Expansion">Filename Expansion</a>.
</p>
</dd>
<dt><tt>e</tt></dt>
<dd><p>Perform <em>parameter expansion</em>, <em>command substitution</em> and
<em>arithmetic expansion</em> on the result. Such expansions can be
nested but too deep recursion may have unpredictable effects.
</p>
</dd>
<dt><tt>f</tt></dt>
<dd><p>Split the result of the expansion at newlines. This is a shorthand
for ‘<tt>ps:\n:</tt>’.
</p>
</dd>
<dt><tt>F</tt></dt>
<dd><p>Join the words of arrays together using newline as a separator.
This is a shorthand for ‘<tt>pj:\n:</tt>’.
</p>
</dd>
<dt><tt>g:</tt><var>opts</var><tt>:</tt></dt>
<dd><p>Process escape sequences like the echo builtin when no options are given
(<tt>g::</tt>). With the <tt>o</tt> option, octal escapes don’t take a leading
zero. With the <tt>c</tt> option, sequences like ‘<tt>^X</tt>’ are also processed.
With the <tt>e</tt> option, processes ‘<tt>\M-t</tt>’ and similar sequences like the
print builtin. With both of the <tt>o</tt> and <tt>e</tt> options, behaves like the
print builtin except that in none of these modes is ‘<tt>\c</tt>’ interpreted.
</p>
</dd>
<dt><tt>i</tt></dt>
<dd><p>Sort case-insensitively. May be combined with ‘<tt>n</tt>’ or ‘<tt>O</tt>’.
</p>
</dd>
<dt><tt>k</tt></dt>
<dd><p>If <var>name</var> refers to an associative array, substitute the <em>keys</em>
(element names) rather than the values of the elements. Used with
subscripts (including ordinary arrays), force indices or keys to be
substituted even if the subscript form refers to values. However,
this flag may not be combined with subscript ranges.
</p>
</dd>
<dt><tt>L</tt></dt>
<dd><p>Convert all letters in the result to lower case.
</p>
</dd>
<dt><tt>n</tt></dt>
<dd><p>Sort decimal integers numerically; if the first differing
characters of two test strings are not digits, sorting
is lexical. Integers with more initial zeroes
are sorted before those with fewer or none. Hence the array ‘<tt>foo1 foo02
foo2 foo3 foo20 foo23</tt>’ is sorted into the order shown.
May be combined with ‘<tt>i</tt>’ or ‘<tt>O</tt>’.
</p>
</dd>
<dt><tt>o</tt></dt>
<dd><p>Sort the resulting words in ascending order; if this appears on its
own the sorting is lexical and case-sensitive (unless the locale
renders it case-insensitive). Sorting in ascending order is the
default for other forms of sorting, so this is ignored if combined
with ‘<tt>a</tt>’, ‘<tt>i</tt>’ or ‘<tt>n</tt>’.
</p>
</dd>
<dt><tt>O</tt></dt>
<dd><p>Sort the resulting words in descending order; ‘<tt>O</tt>’ without ‘<tt>a</tt>’,
‘<tt>i</tt>’ or ‘<tt>n</tt>’ sorts in reverse lexical order. May be combined
with ‘<tt>a</tt>’, ‘<tt>i</tt>’ or ‘<tt>n</tt>’ to reverse the order of sorting.
</p>
</dd>
<dt><tt>P</tt></dt>
<dd><p>This forces the value of the parameter <var>name</var> to be interpreted as a
further parameter name, whose value will be used where appropriate.
Note that flags set with one of the <tt>typeset</tt> family of commands
(in particular case transformations) are not applied to the value of
<var>name</var> used in this fashion.
</p>
<p>If used with a nested parameter or command substitution, the result of that
will be taken as a parameter name in the same way. For example, if you
have ‘<tt>foo=bar</tt>’ and ‘<tt>bar=baz</tt>’, the strings <tt>${(P)foo}</tt>,
<tt>${(P)${foo}}</tt>, and <tt>${(P)$(echo bar)}</tt> will be expanded to
‘<tt>baz</tt>’.
</p>
<p>Likewise, if the reference is itself nested, the expression with the
flag is treated as if it were directly replaced by the parameter name.
It is an error if this nested substitution produces an array with more
than one word. For example, if ‘<tt>name=assoc</tt>’ where the parameter
<tt>assoc</tt> is an associative array, then
‘<tt>${${(P)name}[elt]}</tt>’ refers to the element of the associative
subscripted ‘<tt>elt</tt>’.
</p>
</dd>
<dt><tt>q</tt></dt>
<dd><p>Quote characters that are special to the shell in the resulting words with
backslashes; unprintable or invalid characters are quoted using the
<tt>$'\</tt><var>NNN</var><tt>'</tt> form, with separate quotes for each octet.
</p>
<p>If this flag is given twice, the resulting words are quoted in single
quotes and if it is given three times, the words are quoted in double
quotes; in these forms no special handling of unprintable or invalid
characters is attempted. If the flag is given four times, the words are
quoted in single quotes preceded by a <tt>$</tt>. Note that in all three of
these forms quoting is done unconditionally, even if this does not change
the way the resulting string would be interpreted by the shell.
</p>
<p>If a <tt>q-</tt> is given (only a single <tt>q</tt> may appear), a minimal
form of single quoting is used that only quotes the string if needed to
protect special characters. Typically this form gives the most readable
output.
</p>
<p>If a <tt>q+</tt> is given, an extended form of minmal quoting is used that
causes unprintable characters to be rendered using <tt>$'</tt><var>...</var><tt>'</tt>.
This quoting is similar to that used by the output of values by the
<tt>typeset</tt> family of commands.
</p>
</dd>
<dt><tt>Q</tt></dt>
<dd><p>Remove one level of quotes from the resulting words.
</p>
</dd>
<dt><tt>t</tt></dt>
<dd><p>Use a string describing the type of the parameter where the value
of the parameter would usually appear. This string consists of keywords
separated by hyphens (‘<tt>-</tt>’). The first keyword in the string describes
the main type, it can be one of ‘<tt>scalar</tt>’, ‘<tt>array</tt>’, ‘<tt>integer</tt>’,
‘<tt>float</tt>’ or ‘<tt>association</tt>’. The other keywords describe the type in
more detail:
</p>
<dl compact="compact">
<dt><tt>local</tt></dt>
<dd><p>for local parameters
</p>
</dd>
<dt><tt>left</tt></dt>
<dd><p>for left justified parameters
</p>
</dd>
<dt><tt>right_blanks</tt></dt>
<dd><p>for right justified parameters with leading blanks
</p>
</dd>
<dt><tt>right_zeros</tt></dt>
<dd><p>for right justified parameters with leading zeros
</p>
</dd>
<dt><tt>lower</tt></dt>
<dd><p>for parameters whose value is converted to all lower case when it is
expanded
</p>
</dd>
<dt><tt>upper</tt></dt>
<dd><p>for parameters whose value is converted to all upper case when it is
expanded
</p>
</dd>
<dt><tt>readonly</tt></dt>
<dd><p>for readonly parameters
</p>
</dd>
<dt><tt>tag</tt></dt>
<dd><p>for tagged parameters
</p>
</dd>
<dt><tt>export</tt></dt>
<dd><p>for exported parameters
</p>
</dd>
<dt><tt>unique</tt></dt>
<dd><p>for arrays which keep only the first occurrence of duplicated values
</p>
</dd>
<dt><tt>hide</tt></dt>
<dd><p>for parameters with the ‘hide’ flag
</p>
</dd>
<dt><tt>hideval</tt></dt>
<dd><p>for parameters with the ‘hideval’ flag
</p>
</dd>
<dt><tt>special</tt></dt>
<dd><p>for special parameters defined by the shell
</p>
</dd>
</dl>
</dd>
<dt><tt>u</tt></dt>
<dd><p>Expand only the first occurrence of each unique word.
</p>
</dd>
<dt><tt>U</tt></dt>
<dd><p>Convert all letters in the result to upper case.
</p>
</dd>
<dt><tt>v</tt></dt>
<dd><p>Used with <tt>k</tt>, substitute (as two consecutive words) both the key
and the value of each associative array element. Used with subscripts,
force values to be substituted even if the subscript form refers to
indices or keys.
</p>
</dd>
<dt><tt>V</tt></dt>
<dd><p>Make any special characters in the resulting words visible.
</p>
</dd>
<dt><tt>w</tt></dt>
<dd><p>With <tt>${#</tt><var>name</var><tt>}</tt>, count words in arrays or strings; the <tt>s</tt>
flag may be used to set a word delimiter.
</p>
</dd>
<dt><tt>W</tt></dt>
<dd><p>Similar to <tt>w</tt> with the difference that empty words between
repeated delimiters are also counted.
</p>
</dd>
<dt><tt>X</tt></dt>
<dd><p>With this flag, parsing errors occurring with the <tt>Q</tt>, <tt>e</tt> and <tt>#</tt>
flags or the pattern matching forms such as
‘<tt>${</tt><var>name</var><tt>#</tt><var>pattern</var><tt>}</tt>’ are reported. Without the flag,
errors are silently ignored.
</p>
</dd>
<dt><tt>z</tt></dt>
<dd><p>Split the result of the expansion into words using shell parsing to
find the words, i.e. taking into account any quoting in the value.
Comments are not treated specially but as ordinary strings, similar
to interactive shells with the <tt>INTERACTIVE_COMMENTS</tt> option unset
(however, see the <tt>Z</tt> flag below for related options)
</p>
<p>Note that this is done very late, even later than the ‘<tt>(s)</tt>’ flag. So to
access single words in the result use nested expansions as
in ‘<tt>${${(z)foo}[2]}</tt>’. Likewise, to remove the quotes in the
resulting words use ‘<tt>${(Q)${(z)foo}}</tt>’.
</p>
</dd>
<dt><tt>0</tt></dt>
<dd><p>Split the result of the expansion on null bytes. This is a shorthand
for ‘<tt>ps:\0:</tt>’.
</p>
</dd>
</dl>
<p>The following flags (except <tt>p</tt>) are followed by one or more arguments
as shown. Any character, or the matching pairs ‘<tt>(</tt>...<tt>)</tt>’,
‘<tt>{</tt>...<tt>}</tt>’, ‘<tt>[</tt>...<tt>]</tt>’, or ‘<tt><</tt>...<tt>></tt>’, may be used in place
of a colon as delimiters, but note that when a flag takes more than one
argument, a matched pair of delimiters must surround each argument.
</p>
<dl compact="compact">
<dt><tt>p</tt></dt>
<dd><p>Recognize the same escape sequences as the <tt>print</tt> builtin
in string arguments to any of the flags described below that
follow this argument.
</p>
<p>Alternatively, with this option string arguments may be in the form
<tt>$</tt><var>var</var> in which case the value of the variable is substituted.
Note this form is strict; the string argument does not undergo general
parameter expansion.
</p>
<p>For example,
</p>
<div class="example">
<pre class="example">sep=:
val=a:b:c
print ${(ps.$sep.)val}
</pre></div>
<p>splits the variable on a <tt>:</tt>.
</p>
</dd>
<dt><tt>~</tt></dt>
<dd><p>Strings inserted into the expansion by any of the flags below are to
be treated as patterns. This applies to the string arguments of flags
that follow <tt>~</tt> within the same set of parentheses. Compare with <tt>~</tt>
outside parentheses, which forces the entire substituted string to
be treated as a pattern. Hence, for example,
</p>
<div class="example">
<pre class="example">[[ "?" = ${(~j.|.)array} ]]
</pre></div>
<p>treats ‘<tt>|</tt>’ as a pattern and succeeds if and only if <tt>$array</tt>
contains the string ‘<tt>?</tt>’ as an element. The <tt>~</tt> may be
repeated to toggle the behaviour; its effect only lasts to the
end of the parenthesised group.
</p>
</dd>
<dt><tt>j:</tt><var>string</var><tt>:</tt></dt>
<dd><p>Join the words of arrays together using <var>string</var> as a separator.
<a name="index-SH_005fWORD_005fSPLIT_002c-use-of"></a>
Note that this occurs before field splitting by the <tt>s:</tt><var>string</var><tt>:</tt>
flag or the <tt>SH_WORD_SPLIT</tt> option.
</p>
</dd>
<dt><tt>l:</tt><var>expr</var><tt>::</tt><var>string1</var><tt>::</tt><var>string2</var><tt>:</tt></dt>
<dd><p>Pad the resulting words on the left. Each word will be truncated if
required and placed in a field <var>expr</var> characters wide.
</p>
<p>The arguments <tt>:</tt><var>string1</var><tt>:</tt> and <tt>:</tt><var>string2</var><tt>:</tt> are
optional; neither, the first, or both may be given. Note that the same
pairs of delimiters must be used for each of the three arguments. The
space to the left will be filled with <var>string1</var> (concatenated as
often as needed) or spaces if <var>string1</var> is not given. If both
<var>string1</var> and <var>string2</var> are given, <var>string2</var> is inserted once
directly to the left of each word, truncated if necessary, before
<var>string1</var> is used to produce any remaining padding.
</p>
<p>If either of <var>string1</var> or <var>string2</var> is present but empty,
i.e. there are two delimiters together at that point, the first
character of <tt>$IFS</tt> is used instead.
</p>
<p>If the <tt>MULTIBYTE</tt> option is in effect, the flag <tt>m</tt> may also
be given, in which case widths will be used for the calculation of
padding; otherwise individual multibyte characters are treated as occupying
one unit of width.
</p>
<p>If the <tt>MULTIBYTE</tt> option is not in effect, each byte in the string is
treated as occupying one unit of width.
</p>
<p>Control characters are always assumed to be one unit wide; this allows the
mechanism to be used for generating repetitions of control characters.
</p>
</dd>
<dt><tt>m</tt></dt>
<dd><p>Only useful together with one of the flags <tt>l</tt> or <tt>r</tt> or with the
<tt>#</tt> length operator when the <tt>MULTIBYTE</tt> option
is in effect. Use the character width reported by the system in
calculating how much of the string it occupies or the overall
length of the string. Most printable characters have a width of one
unit, however certain Asian character sets and certain special effects
use wider characters; combining characters have zero width.
Non-printable characters are arbitrarily counted as zero width; how they
would actually be displayed will vary.
</p>
<p>If the <tt>m</tt> is repeated, the character either counts zero (if it has
zero width), else one. For printable character strings this has the
effect of counting the number of glyphs (visibly separate characters),
except for the case where combining characters themselves have non-zero
width (true in certain alphabets).
</p>
</dd>
<dt><tt>r:</tt><var>expr</var><tt>::</tt><var>string1</var><tt>::</tt><var>string2</var><tt>:</tt></dt>
<dd><p>As <tt>l</tt>, but pad the words on the right and insert <var>string2</var>
immediately to the right of the string to be padded.
</p>
<p>Left and right padding may be used together. In this case the strategy
is to apply left padding to the first half width of each of the resulting
words, and right padding to the second half. If the string to be
padded has odd width the extra padding is applied on the left.
</p>
</dd>
<dt><tt>s:</tt><var>string</var><tt>:</tt></dt>
<dd><p>Force field splitting at the
separator <var>string</var>. Note that a <var>string</var> of two or more
characters means that all of them must match in sequence; this differs from
the treatment of two or more characters in the <tt>IFS</tt> parameter.
See also the <tt>=</tt> flag and the <tt>SH_WORD_SPLIT</tt> option. An empty
string may also be given in which case every character will be a separate
element.
</p>
<p>For historical reasons, the usual behaviour that empty array elements
are retained inside double quotes is disabled for arrays generated
by splitting; hence the following:
</p>
<div class="example">
<pre class="example">line="one::three"
print -l "${(s.:.)line}"
</pre></div>
<p>produces two lines of output for <tt>one</tt> and <tt>three</tt> and elides the
empty field. To override this behaviour, supply the ‘<tt>(@)</tt>’ flag as well,
i.e. <tt>"${(@s.:.)line}"</tt>.
</p>
</dd>
<dt><tt>Z:</tt><var>opts</var><tt>:</tt></dt>
<dd><p>As <tt>z</tt> but takes a combination of option letters between a following
pair of delimiter characters. With no options the effect is identical
to <tt>z</tt>. <tt>(Z+c+)</tt>
causes comments to be parsed as a string and retained; any field in the
resulting array beginning with an unquoted comment character is a
comment. <tt>(Z+C+)</tt> causes comments to be parsed
and removed. The rule for comments is standard: anything between a word
starting with the third character of <tt>$HISTCHARS</tt>, default <tt>#</tt>, up to
the next newline is a comment. <tt>(Z+n+)</tt> causes
unquoted newlines to be treated as ordinary whitespace, else they are
treated as if they are shell code delimiters and converted to
semicolons. Options are combined within the same set of delimiters,
e.g. <tt>(Z+Cn+)</tt>.
</p>
</dd>
<dt><tt>_:</tt><var>flags</var><tt>:</tt></dt>
<dd><p>The underscore (<tt>_</tt>) flag is reserved for future use. As of this
revision of zsh, there are no valid <var>flags</var>; anything following an
underscore, other than an empty pair of delimiters, is treated as an
error, and the flag itself has no effect.
</p>
</dd>
</dl>
<p>The following flags are meaningful with the <tt>${</tt>...<tt>#</tt>...<tt>}</tt> or
<tt>${</tt>...<tt>%</tt>...<tt>}</tt> forms. The <tt>S</tt> and <tt>I</tt> flags may also be
used with the <tt>${</tt>...<tt>/</tt>...<tt>}</tt> forms.
</p>
<dl compact="compact">
<dt><tt>S</tt></dt>
<dd><p>Search substrings as well as beginnings or ends; with <tt>#</tt> start
from the beginning and with <tt>%</tt> start from the end of the string.
With substitution via <tt>${</tt>...<tt>/</tt>...<tt>}</tt> or
<tt>${</tt>...<tt>//</tt>...<tt>}</tt>, specifies non-greedy matching, i.e. that the
shortest instead of the longest match should be replaced.
</p>
</dd>
<dt><tt>I:</tt><var>expr</var><tt>:</tt></dt>
<dd><p>Search the <var>expr</var>th match (where <var>expr</var> evaluates to a number).
This only applies when searching for substrings, either with the <tt>S</tt>
flag, or with <tt>${</tt>...<tt>/</tt>...<tt>}</tt> (only the <var>expr</var>th match is
substituted) or <tt>${</tt>...<tt>//</tt>...<tt>}</tt> (all matches from the
<var>expr</var>th on are substituted). The default is to take the first match.
</p>
<p>The <var>expr</var>th match is counted such that there is either one or zero
matches from each starting position in the string, although for global
substitution matches overlapping previous replacements are ignored. With
the <tt>${</tt>...<tt>%</tt>...<tt>}</tt> and <tt>${</tt>...<tt>%%</tt>...<tt>}</tt> forms, the starting
position for the match moves backwards from the end as the index increases,
while with the other forms it moves forward from the start.
</p>
<p>Hence with the string
</p><div class="example">
<pre class="example">which switch is the right switch for Ipswich?
</pre></div>
<p>substitutions of the form
<tt>${</tt>(<tt>SI:</tt><var>N</var><tt>:</tt>)<tt>string#w*ch}</tt> as <var>N</var> increases
from 1 will match and remove ‘<tt>which</tt>’, ‘<tt>witch</tt>’, ‘<tt>witch</tt>’ and
‘<tt>wich</tt>’; the form using ‘<tt>##</tt>’ will match and remove ‘<tt>which switch
is the right switch for Ipswich</tt>’, ‘<tt>witch is the right switch for
Ipswich</tt>’, ‘<tt>witch for Ipswich</tt>’ and ‘<tt>wich</tt>’. The form using ‘<tt>%</tt>’
will remove the same matches as for ‘<tt>#</tt>’, but in reverse order, and the
form using ‘<tt>%%</tt>’ will remove the same matches as for ‘<tt>##</tt>’ in reverse
order.
</p>
</dd>
<dt><tt>B</tt></dt>
<dd><p>Include the index of the beginning of the match in the result.
</p>
</dd>
<dt><tt>E</tt></dt>
<dd><p>Include the index one character past the end of the match in the result
(note this is inconsistent with other uses of parameter index).
</p>
</dd>
<dt><tt>M</tt></dt>
<dd><p>Include the matched portion in the result.
</p>
</dd>
<dt><tt>N</tt></dt>
<dd><p>Include the length of the match in the result.
</p>
</dd>
<dt><tt>R</tt></dt>
<dd><p>Include the unmatched portion in the result (the <em>R</em>est).
</p>
</dd>
</dl>
<hr>
<a name="Rules"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion-Flags" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Examples" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.3.2 Rules</h3>
<p>Here is a summary of the rules for substitution; this assumes that braces
are present around the substitution, i.e. <tt>${</tt><var>...</var><tt>}</tt>. Some particular
examples are given below. Note that the Zsh Development Group accepts
<em>no responsibility</em> for any brain damage which may occur during the
reading of the following rules.
</p>
<dl compact="compact">
<dt><tt>1.</tt> <em>Nested substitution</em></dt>
<dd><p>If multiple nested <tt>${</tt><var>...</var><tt>}</tt> forms are present, substitution is
performed from the inside outwards. At each level, the substitution takes
account of whether the current value is a scalar or an array, whether the
whole substitution is in double quotes, and what flags are supplied to the
current level of substitution, just as if the nested substitution were the
outermost. The flags are not propagated up to enclosing
substitutions; the nested substitution will return either a scalar or an
array as determined by the flags, possibly adjusted for quoting. All the
following steps take place where applicable at all levels of substitution.
</p>
<p>Note that, unless the ‘<tt>(P)</tt>’ flag is present, the flags and any
subscripts apply directly to the value of the nested substitution; for
example, the expansion <tt>${${foo}}</tt> behaves exactly the same as
<tt>${foo}</tt>. When the ‘<tt>(P)</tt>’ flag is present in a nested substitution,
the other substitution rules are applied to the value <em>before</em> it is
interpreted as a name, so <tt>${${(P)foo}}</tt> may differ from <tt>${(P)foo}</tt>.
</p>
<p>At each nested level of substitution, the substituted words undergo all
forms of single-word substitution (i.e. not filename generation), including
command substitution, arithmetic expansion and filename expansion
(i.e. leading <tt>~</tt> and <tt>=</tt>). Thus, for example, <tt>${${:-=cat}:h}</tt>
expands to the directory where the <tt>cat</tt> program resides. (Explanation:
the internal substitution has no parameter but a default value <tt>=cat</tt>,
which is expanded by filename expansion to a full path; the outer
substitution then applies the modifier <tt>:h</tt> and takes the directory part
of the path.)
</p>
</dd>
<dt><tt>2.</tt> <em>Internal parameter flags</em></dt>
<dd><p>Any parameter flags set by one of the <tt>typeset</tt> family of commands, in
particular the <tt>-L</tt>, <tt>-R</tt>, <tt>-Z</tt>, <tt>-u</tt> and <tt>-l</tt> options for
padding and capitalization, are applied directly to the parameter value.
Note these flags are options to the command, e.g. ‘<tt>typeset -Z</tt>’; they
are not the same as the flags used within parameter substitutions.
</p>
<p>At the outermost level of substitution, the ‘<tt>(P)</tt>’ flag (rule <tt>4.</tt>)
ignores these transformations and uses the unmodified value of the
parameter as the name to be replaced. This is usually the desired
behavior because padding may make the value syntactically illegal as a
parameter name, but if capitalization changes are desired, use the
<tt>${${(P)foo}}</tt> form (rule <tt>25.</tt>).
</p>
</dd>
<dt><tt>3.</tt> <em>Parameter subscripting</em></dt>
<dd><p>If the value is a raw parameter reference with a subscript, such as
<tt>${</tt><var>var</var><tt>[3]}</tt>, the effect of subscripting is applied directly to
the parameter. Subscripts are evaluated left to right; subsequent
subscripts apply to the scalar or array value yielded by the previous
subscript. Thus if <tt>var</tt> is an array, <tt>${var[1][2]}</tt> is the second
character of the first word, but <tt>${var[2,4][2]}</tt> is the entire third
word (the second word of the range of words two through four of the
original array). Any number of subscripts may appear. Flags such as
‘<tt>(k)</tt>’ and ‘<tt>(v)</tt>’ which alter the result of subscripting are applied.
</p>
</dd>
<dt><tt>4.</tt> <em>Parameter name replacement</em></dt>
<dd><p>At the outermost level of nesting only, the ‘<tt>(P)</tt>’ flag is applied. This
treats the value so far as a parameter name (which may include a subscript
expression) and replaces that with the corresponding value. This
replacement occurs later if the ‘<tt>(P)</tt>’ flag appears in a nested
substitution.
</p>
<p>If the value so far names a parameter that has internal flags (rule <tt>2.</tt>),
those internal flags are applied to the new value after replacement.
</p>
</dd>
<dt><tt>5.</tt> <em>Double-quoted joining</em></dt>
<dd><p>If the value after this process is an array, and the substitution
appears in double quotes, and neither an ‘<tt>(@)</tt>’ flag nor a ‘<tt>#</tt>’
length operator is present at the current level, then words of the
value are joined with the first character of the parameter <tt>$IFS</tt>,
by default a space, between each word (single word arrays are not
modified). If the ‘<tt>(j)</tt>’ flag is present, that is used for joining
instead of <tt>$IFS</tt>.
</p>
</dd>
<dt><tt>6.</tt> <em>Nested subscripting</em></dt>
<dd><p>Any remaining subscripts (i.e. of a nested substitution) are evaluated at
this point, based on whether the value is an array or a scalar. As with
<tt>3.</tt>, multiple subscripts can appear. Note that <tt>${foo[2,4][2]}</tt> is
thus equivalent to <tt>${${foo[2,4]}[2]}</tt> and also to
<tt>"${${(@)foo[2,4]}[2]}"</tt> (the nested substitution returns an array in
both cases), but not to <tt>"${${foo[2,4]}[2]}"</tt> (the nested substitution
returns a scalar because of the quotes).
</p>
</dd>
<dt><tt>7.</tt> <em>Modifiers</em></dt>
<dd><p>Any modifiers, as specified by a trailing ‘<tt>#</tt>’, ‘<tt>%</tt>’, ‘<tt>/</tt>’
(possibly doubled) or by a set of modifiers of the form ‘<tt>:...</tt>’ (see
<a href="#Modifiers">Modifiers</a> in <a href="#History-Expansion">History Expansion</a>), are applied to the words
of the value at this level.
</p>
</dd>
<dt><tt>8.</tt> <em>Character evaluation</em></dt>
<dd><p>Any ‘<tt>(#)</tt>’ flag is applied, evaluating the result so far numerically
as a character.
</p>
</dd>
<dt><tt>9.</tt> <em>Length</em></dt>
<dd><p>Any initial ‘<tt>#</tt>’ modifier, i.e. in the form <tt>${#</tt><var>var</var><tt>}</tt>, is
used to evaluate the length of the expression so far.
</p>
</dd>
<dt><tt>10.</tt> <em>Forced joining</em></dt>
<dd><p>If the ‘<tt>(j)</tt>’ flag is present, or no ‘<tt>(j)</tt>’ flag is present but
the string is to be split as given by rule <tt>11.</tt>, and joining
did not take place at rule <tt>5.</tt>, any words in the value are joined
together using the given string or the first character of <tt>$IFS</tt> if none.
Note that the ‘<tt>(F)</tt>’ flag implicitly supplies a string for joining in this
manner.
</p>
</dd>
<dt><tt>11.</tt> <em>Simple word splitting</em></dt>
<dd><p>If one of the ‘<tt>(s)</tt>’ or ‘<tt>(f)</tt>’ flags are present, or the ‘<tt>=</tt>’
specifier was present (e.g. <tt>${=</tt><var>var</var><tt>}</tt>), the word is split on
occurrences of the specified string, or (for <tt>=</tt> with neither of the two
flags present) any of the characters in <tt>$IFS</tt>.
</p>
<p>If no ‘<tt>(s)</tt>’, ‘<tt>(f)</tt>’ or ‘<tt>=</tt>’ was given, but the word is not
quoted and the option <tt>SH_WORD_SPLIT</tt> is set, the word is split on
occurrences of any of the characters in <tt>$IFS</tt>. Note this step, too,
takes place at all levels of a nested substitution.
</p>
</dd>
<dt><tt>12.</tt> <em>Case modification</em></dt>
<dd><p>Any case modification from one of the flags ‘<tt>(L)</tt>’, ‘<tt>(U)</tt>’ or ‘<tt>(C)</tt>’
is applied.
</p>
</dd>
<dt><tt>13.</tt> <em>Escape sequence replacement</em></dt>
<dd><p>First any replacements from the ‘<tt>(g)</tt>’ flag are performed, then any
prompt-style formatting from the ‘<tt>(%)</tt>’ family of flags is applied.
</p>
</dd>
<dt><tt>14.</tt> <em>Quote application</em></dt>
<dd><p>Any quoting or unquoting using ‘<tt>(q)</tt>’ and ‘<tt>(Q)</tt>’ and related flags
is applied.
</p>
</dd>
<dt><tt>15.</tt> <em>Directory naming</em></dt>
<dd><p>Any directory name substitution using ‘<tt>(D)</tt>’ flag is applied.
</p>
</dd>
<dt><tt>16.</tt> <em>Visibility enhancement</em></dt>
<dd><p>Any modifications to make characters visible using the ‘<tt>(V)</tt>’ flag
are applied.
</p>
</dd>
<dt><tt>17.</tt> <em>Lexical word splitting</em></dt>
<dd><p>If the ’<tt>(z)</tt>’ flag or one of the forms of the ’<tt>(Z)</tt>’ flag is
present, the word is split as if it were a shell command line, so that
quotation marks and other metacharacters are used to decide what
constitutes a word. Note this form of splitting is entirely distinct
from that described by rule <tt>11.</tt>: it does not use <tt>$IFS</tt>, and
does not cause forced joining.
</p>
</dd>
<dt><tt>18.</tt> <em>Uniqueness</em></dt>
<dd><p>If the result is an array and the ‘<tt>(u)</tt>’ flag was present, duplicate
elements are removed from the array.
</p>
</dd>
<dt><tt>19.</tt> <em>Ordering</em></dt>
<dd><p>If the result is still an array and one of the ‘<tt>(o)</tt>’ or ‘<tt>(O)</tt>’ flags
was present, the array is reordered.
</p>
</dd>
<dt><tt>20.</tt> <tt>RC_EXPAND_PARAM</tt></dt>
<dd><p>At this point the decision is made whether any resulting array elements
are to be combined element by element with surrounding text, as given
by either the <tt>RC_EXPAND_PARAM</tt> option or the ‘<tt>^</tt>’ flag.
</p>
</dd>
<dt><tt>21.</tt> <em>Re-evaluation</em></dt>
<dd><p>Any ‘<tt>(e)</tt>’ flag is applied to the value, forcing it to be re-examined
for new parameter substitutions, but also for command and arithmetic
substitutions.
</p>
</dd>
<dt><tt>22.</tt> <em>Padding</em></dt>
<dd><p>Any padding of the value by the ‘<tt>(l.</tt><var>fill</var><tt>.)</tt>’ or
‘<tt>(r.</tt><var>fill</var><tt>.)</tt>’ flags is applied.
</p>
</dd>
<dt><tt>23.</tt> <em>Semantic joining</em></dt>
<dd><p>In contexts where expansion semantics requires a single word to
result, all words are rejoined with the first character of <tt>IFS</tt>
between. So in ‘<tt>${(P</tt><tt>)${(f</tt><tt>)lines}}</tt>’
the value of <tt>${lines}</tt> is split at newlines, but then must be
joined again before the ‘<tt>(P)</tt>’ flag can be applied.
</p>
<p>If a single word is not required, this rule is skipped.
</p>
</dd>
<dt><tt>24.</tt> <em>Empty argument removal</em></dt>
<dd><p>If the substitution does not appear in double quotes, any resulting
zero-length argument, whether from a scalar or an element of an array,
is elided from the list of arguments inserted into the command line.
</p>
<p>Strictly speaking, the removal happens later as the same happens with
other forms of substitution; the point to note here is simply that
it occurs after any of the above parameter operations.
</p>
</dd>
<dt><tt>25.</tt> <em>Nested parameter name replacement</em></dt>
<dd><p>If the ‘<tt>(P)</tt>’ flag is present and rule <tt>4.</tt> has not applied, the
value so far is treated as a parameter name (which may include a subscript
expression) and replaced with the corresponding value, with internal flags
(rule <tt>2.</tt>) applied to the new value.
</p>
</dd>
</dl>
<hr>
<a name="Examples"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Rules" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Parameter-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Command-Substitution" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.3.3 Examples</h3>
<p>The flag <tt>f</tt> is useful to split a double-quoted substitution line by
line. For example, <tt>${(f)"$(<</tt><var>file</var><tt>)"}</tt>
substitutes the contents of <var>file</var> divided so that each line is
an element of the resulting array. Compare this with the effect of
<tt>$</tt><tt>(<</tt><var>file</var><tt>)</tt> alone, which divides the file
up by words, or the same inside double quotes, which makes the entire
content of the file a single string.
</p>
<p>The following illustrates the rules for nested parameter expansions.
Suppose that <tt>$foo</tt> contains the array <tt>(bar baz</tt><tt>)</tt>:
</p>
<dl compact="compact">
<dt><tt>"${(@)${foo}[1]}"</tt></dt>
<dd><p>This produces the result <tt>b</tt>. First, the inner substitution
<tt>"${foo}"</tt>, which has no array (<tt>@</tt>) flag, produces a single word
result <tt>"bar baz"</tt>. The outer substitution <tt>"${(@)...[1]}"</tt> detects
that this is a scalar, so that (despite the ‘<tt>(@)</tt>’ flag) the subscript
picks the first character.
</p>
</dd>
<dt><tt>"${${(@)foo}[1]}"</tt></dt>
<dd><p>This produces the result ‘<tt>bar</tt>’. In this case, the inner substitution
<tt>"${(@)foo}"</tt> produces the array ‘<tt>(bar baz</tt><tt>)</tt>’. The outer
substitution <tt>"${...[1]}"</tt> detects that this is an array and picks the
first word. This is similar to the simple case <tt>"${foo[1]}"</tt>.
</p>
</dd>
</dl>
<p>As an example of the rules for word splitting and joining, suppose <tt>$foo</tt>
contains the array ‘<tt>(ax1 bx1</tt><tt>)</tt>’. Then
</p>
<dl compact="compact">
<dt><tt>${(s/x/)foo}</tt></dt>
<dd><p>produces the words ‘<tt>a</tt>’, ‘<tt>1 b</tt>’ and ‘<tt>1</tt>’.
</p>
</dd>
<dt><tt>${(j/x/s/x/)foo}</tt></dt>
<dd><p>produces ‘<tt>a</tt>’, ‘<tt>1</tt>’, ‘<tt>b</tt>’ and ‘<tt>1</tt>’.
</p>
</dd>
<dt><tt>${(s/x/)foo%%1*}</tt></dt>
<dd><p>produces ‘<tt>a</tt>’ and ‘<tt> b</tt>’ (note the extra space). As substitution
occurs before either joining or splitting, the operation first generates
the modified array <tt>(ax bx</tt><tt>)</tt>, which is joined to give
<tt>"ax bx"</tt>, and then split to give ‘<tt>a</tt>’, ‘<tt> b</tt>’ and ‘’. The final
empty string will then be elided, as it is not in double quotes.
</p>
</dd>
</dl>
<hr>
<a name="Command-Substitution"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Examples" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Arithmetic-Expansion" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Command-Substitution-1"></a>
<h2 class="section">14.4 Command Substitution</h2>
<p><a name="index-command-substitution"></a>
<a name="index-substitution_002c-command"></a>
A command enclosed in parentheses preceded by a dollar sign, like
‘<tt>$(</tt>...<tt>)</tt>’, or quoted with grave
accents, like ‘<tt>`</tt>...<tt>`</tt>’, is replaced with its standard output, with
any trailing newlines deleted.
If the substitution is not enclosed in double quotes, the
output is broken into words using the <tt>IFS</tt> parameter.
<a name="index-IFS_002c-use-of-1"></a>
The substitution ‘<tt>$(cat</tt> <var>foo</var><tt>)</tt>’ may be replaced
by the equivalent but faster ‘<tt>$(<</tt><var>foo</var><tt>)</tt>’.
In either case, if the option <tt>GLOB_SUBST</tt> is set,
the output is eligible for filename generation.
</p><hr>
<a name="Arithmetic-Expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Command-Substitution" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Brace-Expansion" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Arithmetic-Expansion-1"></a>
<h2 class="section">14.5 Arithmetic Expansion</h2>
<p><a name="index-arithmetic-expansion"></a>
<a name="index-expansion_002c-arithmetic"></a>
A string of the form ‘<tt>$[</tt><var>exp</var><tt>]</tt>’ or
‘<tt>$((</tt><var>exp</var><tt>))</tt>’ is substituted
with the value of the arithmetic expression <var>exp</var>. <var>exp</var> is
subjected to <em>parameter expansion</em>, <em>command substitution</em>
and <em>arithmetic expansion</em> before it is evaluated.
See <a href="Arithmetic-Evaluation.html#Arithmetic-Evaluation">Arithmetic Evaluation</a>.
</p><hr>
<a name="Brace-Expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Arithmetic-Expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Expansion" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Brace-Expansion-1"></a>
<h2 class="section">14.6 Brace Expansion</h2>
<p><a name="index-brace-expansion"></a>
<a name="index-expansion_002c-brace"></a>
A string of the form
‘<var>foo</var><tt>{</tt><var>xx</var><tt>,</tt><var>yy</var><tt>,</tt><var>zz</var><tt>}</tt><var>bar</var>’
is expanded to the individual words
‘<var>fooxxbar</var>’, ‘<var>fooyybar</var>’ and ‘<var>foozzbar</var>’.
Left-to-right order is preserved. This construct
may be nested. Commas may be quoted in order to
include them literally in a word.
</p>
<p>An expression of the form ‘<tt>{</tt><var>n1</var><tt>..</tt><var>n2</var><tt>}</tt>’,
where <var>n1</var> and <var>n2</var> are integers,
is expanded to every number between
<var>n1</var> and <var>n2</var> inclusive. If either number begins with a
zero, all the resulting numbers will be padded with leading zeroes to
that minimum width, but for negative numbers the <tt>-</tt> character is also
included in the width. If the numbers are in decreasing order the
resulting sequence will also be in decreasing order.
</p>
<p>An expression of the form ‘<tt>{</tt><var>n1</var><tt>..</tt><var>n2</var><tt>..</tt><var>n3</var><tt>}</tt>’,
where <var>n1</var>, <var>n2</var>, and <var>n3</var> are integers,
is expanded as above, but only every <var>n3</var>th number starting from <var>n1</var>
is output. If <var>n3</var> is negative the numbers are output in reverse order,
this is slightly different from simply swapping <var>n1</var> and <var>n2</var> in the case
that the step <var>n3</var> doesn’t evenly divide the range. Zero padding can be
specified in any of the three numbers, specifying it in the third can be useful
to pad for example ‘<tt>{-99..100..01}</tt>’ which is not possible to specify by putting a
0 on either of the first two numbers (i.e. pad to two characters).
</p>
<p>An expression of the form ‘<tt>{</tt><var>c1</var><tt>..</tt><var>c2</var><tt>}</tt>’, where
<var>c1</var> and <var>c2</var> are single characters (which may be multibyte
characters), is expanded to every character in the range from <var>c1</var> to
<var>c2</var> in whatever character sequence is used internally. For
characters with code points below 128 this is US ASCII (this is the only
case most users will need). If any intervening character is not
printable, appropriate quotation is used to render it printable.
If the character sequence is reversed, the output is in reverse
order, e.g. ‘<tt>{d..a}</tt>’ is substituted as ‘<tt>d c b a</tt>’.
</p>
<p>If a brace expression matches none of the above forms, it is left
unchanged, unless the option <tt>BRACE_CCL</tt> (an abbreviation for ‘brace
character class’) is set.
<a name="index-BRACE_005fCCL_002c-use-of"></a>
In that case, it is expanded to a list of the individual
characters between the braces sorted into the order of the characters
in the ASCII character set (multibyte characters are not currently
handled). The syntax is similar to a
<tt>[</tt>...<tt>]</tt> expression in filename generation:
‘<tt>-</tt>’ is treated specially to denote a range of characters, but ‘<tt>^</tt>’ or
‘<tt>!</tt>’ as the first character is treated normally. For example,
‘<tt>{abcdef0-9}</tt>’ expands to 16 words <tt>0 1 2 3 4 5 6 7 8 9 a b c d e f</tt>.
</p>
<p>Note that brace expansion is not part of filename generation (globbing); an
expression such as <tt>*/{foo,bar}</tt> is split into two separate words
<tt>*/foo</tt> and <tt>*/bar</tt> before filename generation takes place. In
particular, note that this is liable to produce a ‘no match’ error if
<em>either</em> of the two expressions does not match; this is to be contrasted
with <tt>*/(foo|bar)</tt>, which is treated as a single pattern but otherwise
has similar effects.
</p>
<p>To combine brace expansion with array expansion, see the
<tt>${^</tt><var>spec</var><tt>}</tt> form described
in <a href="#Parameter-Expansion">Parameter Expansion</a>
above.
</p>
<hr>
<a name="Filename-Expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Brace-Expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Dynamic-named-directories" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Filename-Expansion-1"></a>
<h2 class="section">14.7 Filename Expansion</h2>
<p><a name="index-filename-expansion"></a>
<a name="index-expansion_002c-filename"></a>
Each word is checked to see if it begins with an unquoted ‘<tt>~</tt>’.
If it does, then the word up to a ‘<tt>/</tt>’,
or the end of the word if there is no ‘<tt>/</tt>’,
is checked to see if it can be substituted in one of the ways
described here. If so, then the ‘<tt>~</tt>’ and the checked portion are
replaced with the appropriate substitute value.
</p>
<p>A ‘<tt>~</tt>’ by itself is replaced by the value of <tt>$HOME</tt>.
A ‘<tt>~</tt>’ followed by a ‘<tt>+</tt>’ or a ‘<tt>-</tt>’ is replaced by current
or previous working directory, respectively.
</p>
<p>A ‘<tt>~</tt>’ followed by a number is replaced by the directory at that
position in the directory stack.
‘<tt>~0</tt>’ is equivalent to ‘<tt>~+</tt>’,
and ‘<tt>~1</tt>’ is the top of the stack.
‘<tt>~+</tt>’ followed by a number is replaced by the directory at that
position in the directory stack.
‘<tt>~+0</tt>’ is equivalent to ‘<tt>~+</tt>’,
and ‘<tt>~+1</tt>’ is the top of the stack.
‘<tt>~-</tt>’ followed by a number is replaced by the directory that
many positions from the bottom of the stack.
‘<tt>~-0</tt>’ is the bottom of the stack.
<a name="index-PUSHD_005fMINUS_002c-use-of"></a>
The <tt>PUSHD_MINUS</tt>
option exchanges the effects of ‘<tt>~+</tt>’ and ‘<tt>~-</tt>’ where they are
followed by a number.
</p>
<hr>
<a name="Dynamic-named-directories"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Static-named-directories" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.7.1 Dynamic named directories</h3>
<p><a name="index-directories_002c-named_002c-dynamic"></a>
<a name="index-named-directories_002c-dynamic"></a>
<a name="index-dynamic-named-directories"></a>
</p>
<p>If the function <tt>zsh_directory_name</tt> exists, or the shell variable
<tt>zsh_directory_name_functions</tt> exists and contains an array of
function names, then the functions are used to implement dynamic
directory naming. The functions are tried in order until one returns
status zero, so it is important that functions test whether they can
handle the case in question and return an appropriate status.
</p>
<p>A ‘<tt>~</tt>’ followed by a string <var>namstr</var> in unquoted square brackets is
treated specially as a dynamic directory name. Note that the first
unquoted closing square bracket always terminates <var>namstr</var>. The shell
function is passed two arguments: the string <tt>n</tt> (for name) and
<var>namstr</var>. It should either set the array <tt>reply</tt> to a single element
which is the directory corresponding to the name and return status zero
(executing an assignment as the last statement is usually sufficient), or
it should return status non-zero. In the former case the element of reply
is used as the directory; in the latter case the substitution is deemed to
have failed. If all functions fail and the option <tt>NOMATCH</tt> is set,
an error results.
</p>
<p>The functions defined as above are also used to see if a directory can
be turned into a name, for example when printing the directory stack or
when expanding <tt>%~</tt> in prompts. In this case each function is passed two
arguments: the string <tt>d</tt> (for directory) and the candidate for dynamic
naming. The function should either return non-zero status, if the
directory cannot be named by the function, or it should set the array reply
to consist of two elements: the first is the dynamic name for the directory
(as would appear within ‘<tt>~[</tt><var>...</var><tt>]</tt>’), and the second is the
prefix length of the directory to be replaced. For example, if the trial
directory is <tt>/home/myname/src/zsh</tt> and the dynamic name for
<tt>/home/myname/src</tt> (which has 16 characters) is <tt>s</tt>, then the function
sets
</p>
<div class="example">
<pre class="example">reply=(s 16)
</pre></div>
<p>The directory name so returned is compared with possible static names for
parts of the directory path, as described below; it is used if the prefix
length matched (16 in the example) is longer than that matched by any
static name.
</p>
<p>It is not a requirement that a function implements both
<tt>n</tt> and <tt>d</tt> calls; for example, it might be appropriate for certain
dynamic forms of expansion not to be contracted to names. In that case
any call with the first argument <tt>d</tt> should cause a non-zero status to
be returned.
</p>
<p>The completion system calls ‘<tt>zsh_directory_name c</tt>’ followed by
equivalent calls to elements of the array
<tt>zsh_directory_name_functions</tt>, if it exists, in order to
complete dynamic names for directories. The code for this should be
as for any other completion function as described in
<a href="Completion-System.html#Completion-System">Completion System</a>.
</p>
<p>As a working example, here is a function that expands any dynamic names
beginning with the string <tt>p:</tt> to directories below
<tt>/home/pws/perforce</tt>. In this simple case a static name for the
directory would be just as effective.
</p>
<div class="example">
<pre class="example">zsh_directory_name() {
emulate -L zsh
setopt extendedglob
local -a match mbegin mend
if [[ $1 = d ]]; then
# turn the directory into a name
if [[ $2 = (#b)(/home/pws/perforce/)([^/]##)* ]]; then
typeset -ga reply
reply=(p:$match[2] $(( ${#match[1]} + ${#match[2]} )) )
else
return 1
fi
elif [[ $1 = n ]]; then
# turn the name into a directory
[[ $2 != (#b)p:(?*) ]] && return 1
typeset -ga reply
reply=(/home/pws/perforce/$match[1])
elif [[ $1 = c ]]; then
# complete names
local expl
local -a dirs
dirs=(/home/pws/perforce/*(/:t))
dirs=(p:${^dirs})
_wanted dynamic-dirs expl 'dynamic directory' compadd -S\] -a dirs
return
else
return 1
fi
return 0
}
</pre></div>
<hr>
<a name="Static-named-directories"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Dynamic-named-directories" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#g_t_0060_003d_0027-expansion" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.7.2 Static named directories</h3>
<p><a name="index-directories_002c-named_002c-static"></a>
<a name="index-named-directories_002c-static"></a>
<a name="index-static-named-directories"></a>
A ‘<tt>~</tt>’ followed by anything not already covered consisting
of any number of alphanumeric characters or underscore (‘<tt>_</tt>’),
hyphen (‘<tt>-</tt>’), or dot (‘<tt>.</tt>’) is looked up as a
named directory, and replaced by the value of that named directory if found.
Named directories are typically home directories for users on the system.
They may also be defined if the text after the ‘<tt>~</tt>’ is the name
of a string shell parameter whose value begins with a ‘<tt>/</tt>’.
Note that trailing slashes will be removed from the path to the directory
(though the original parameter is not modified).
</p>
<p>It is also possible to define directory names using the <tt>-d</tt> option to the
<tt>hash</tt> builtin.
</p>
<p>When the shell prints a path (e.g. when expanding <tt>%~</tt> in prompts or when
printing the directory stack), the path is checked to see if it has a named
directory as its prefix. If so, then the prefix portion is replaced with a
‘<tt>~</tt>’ followed by the name of the directory.
The shorter of the two ways of referring to the directory is used,
i.e. either the directory name or the full path; the name is used
if they are the same length.
The parameters <tt>$PWD</tt> and <tt>$OLDPWD</tt> are never abbreviated in this fashion.
</p>
<hr>
<a name="g_t_0060_003d_0027-expansion"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Static-named-directories" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Notes" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.7.3 ‘=’ expansion</h3>
<p>If a word begins with an unquoted ‘<tt>=</tt>’
and the <tt>EQUALS</tt> option is set,
the remainder of the word is taken as the
name of a command. If a command
exists by that name, the word is replaced
by the full pathname of the command.
</p>
<hr>
<a name="Notes"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#g_t_0060_003d_0027-expansion" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.7.4 Notes</h3>
<p>Filename expansion is performed on the right hand side of a parameter
assignment, including those appearing after commands of the
<tt>typeset</tt> family. In this case, the right hand side will be treated
as a colon-separated list in the manner of the <tt>PATH</tt> parameter,
so that a ‘<tt>~</tt>’ or an ‘<tt>=</tt>’ following a ‘<tt>:</tt>’ is eligible for expansion.
All such behaviour can be
disabled by quoting the ‘<tt>~</tt>’, the ‘<tt>=</tt>’, or the whole expression (but not
simply the colon); the <tt>EQUALS</tt> option is also respected.
</p>
<p>If the option <tt>MAGIC_EQUAL_SUBST</tt> is set, any unquoted shell
argument in the form ‘<var>identifier</var><tt>=</tt><var>expression</var>’ becomes eligible
for file expansion as described in the previous paragraph. Quoting the
first ‘<tt>=</tt>’ also inhibits this.
</p>
<hr>
<a name="Filename-Generation"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Notes" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Expansion" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Glob-Operators" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<a name="Filename-Generation-1"></a>
<h2 class="section">14.8 Filename Generation</h2>
<p><a name="index-filename-generation"></a>
If a word contains an unquoted instance of one of the characters
‘<tt>*</tt>’, ‘<tt>(</tt>’, ‘<tt>|</tt>’, ‘<tt><</tt>’, ‘<tt>[</tt>’, or ‘<tt>?</tt>’, it is regarded
as a pattern for filename generation, unless the <tt>GLOB</tt> option is unset.
<a name="index-GLOB_002c-use-of"></a>
If the <tt>EXTENDED_GLOB</tt> option is set,
<a name="index-EXTENDED_005fGLOB_002c-use-of"></a>
the ‘<tt>^</tt>’ and ‘<tt>#</tt>’ characters also denote a pattern; otherwise
they are not treated specially by the shell.
</p>
<p>The word is replaced with a list of sorted filenames that match
the pattern. If no matching pattern is found, the shell gives
an error message, unless the <tt>NULL_GLOB</tt> option is set,
<a name="index-NULL_005fGLOB_002c-use-of"></a>
in which case the word is deleted; or unless the <tt>NOMATCH</tt>
option is unset, in which case the word is left unchanged.
<a name="index-NOMATCH_002c-use-of"></a>
</p>
<p>In filename generation,
the character ‘<tt>/</tt>’ must be matched explicitly;
also, a ‘<tt>.</tt>’ must be matched
explicitly at the beginning of a pattern or after a ‘<tt>/</tt>’, unless the
<tt>GLOB_DOTS</tt> option is set.
<a name="index-GLOB_005fDOTS_002c-use-of"></a>
No filename generation pattern
matches the files ‘<tt>.</tt>’ or ‘<tt>..</tt>’. In other instances of pattern
matching, the ‘<tt>/</tt>’ and ‘<tt>.</tt>’ are not treated specially.
</p>
<hr>
<a name="Glob-Operators"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#ksh_002dlike-Glob-Operators" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.1 Glob Operators</h3>
<dl compact="compact">
<dt><tt>*</tt></dt>
<dd><p>Matches any string, including the null string.
</p>
</dd>
<dt><tt>?</tt></dt>
<dd><p>Matches any character.
</p>
</dd>
<dt><tt>[</tt>...<tt>]</tt></dt>
<dd><p>Matches any of the enclosed characters. Ranges of characters
can be specified by separating two characters by a ‘<tt>-</tt>’.
A ‘<tt>-</tt>’ or ‘<tt>]</tt>’ may be matched by including it as the
first character in the list.
<a name="index-character-classes"></a>
There are also several named classes of characters, in the form
‘<tt>[:</tt><var>name</var><tt>:]</tt>’ with the following meanings.
The first set use the macros provided by
the operating system to test for the given character combinations,
including any modifications due to local language settings, see
man page ctype(3):
</p>
<dl compact="compact">
<dt><tt>[:alnum:]</tt></dt>
<dd><p>The character is alphanumeric
</p>
</dd>
<dt><tt>[:alpha:]</tt></dt>
<dd><p>The character is alphabetic
</p>
</dd>
<dt><tt>[:ascii:]</tt></dt>
<dd><p>The character is 7-bit, i.e. is a single-byte character without
the top bit set.
</p>
</dd>
<dt><tt>[:blank:]</tt></dt>
<dd><p>The character is either space or tab
</p>
</dd>
<dt><tt>[:cntrl:]</tt></dt>
<dd><p>The character is a control character
</p>
</dd>
<dt><tt>[:digit:]</tt></dt>
<dd><p>The character is a decimal digit
</p>
</dd>
<dt><tt>[:graph:]</tt></dt>
<dd><p>The character is a printable character other than whitespace
</p>
</dd>
<dt><tt>[:lower:]</tt></dt>
<dd><p>The character is a lowercase letter
</p>
</dd>
<dt><tt>[:print:]</tt></dt>
<dd><p>The character is printable
</p>
</dd>
<dt><tt>[:punct:]</tt></dt>
<dd><p>The character is printable but neither alphanumeric nor whitespace
</p>
</dd>
<dt><tt>[:space:]</tt></dt>
<dd><p>The character is whitespace
</p>
</dd>
<dt><tt>[:upper:]</tt></dt>
<dd><p>The character is an uppercase letter
</p>
</dd>
<dt><tt>[:xdigit:]</tt></dt>
<dd><p>The character is a hexadecimal digit
</p>
</dd>
</dl>
<p>Another set of named classes is handled internally by the shell and
is not sensitive to the locale:
</p>
<dl compact="compact">
<dt><tt>[:IDENT:]</tt></dt>
<dd><p>The character is allowed to form part of a shell identifier, such
as a parameter name
</p>
</dd>
<dt><tt>[:IFS:]</tt></dt>
<dd><p>The character is used as an input field separator, i.e. is contained in the
<tt>IFS</tt> parameter
</p>
</dd>
<dt><tt>[:IFSSPACE:]</tt></dt>
<dd><p>The character is an IFS white space character; see the documentation
for <tt>IFS</tt> in
<a href="Parameters.html#Parameters-Used-By-The-Shell">Parameters Used By The Shell</a>.
</p>
</dd>
<dt><tt>[:INCOMPLETE:]</tt></dt>
<dd><p>Matches a byte that starts an incomplete multibyte character.
Note that there may be a sequence of more than one bytes that
taken together form the prefix of a multibyte character. To
test for a potentially incomplete byte sequence, use the pattern
‘<tt>[[:INCOMPLETE:]]*</tt>’. This will never match a sequence starting
with a valid multibyte character.
</p>
</dd>
<dt><tt>[:INVALID:]</tt></dt>
<dd><p>Matches a byte that does not start a valid multibyte character.
Note this may be a continuation byte of an incomplete multibyte
character as any part of a multibyte string consisting of invalid and
incomplete multibyte characters is treated as single bytes.
</p>
</dd>
<dt><tt>[:WORD:]</tt></dt>
<dd><p>The character is treated as part of a word; this test is sensitive
to the value of the <tt>WORDCHARS</tt> parameter
</p>
</dd>
</dl>
<p>Note that the square brackets are additional
to those enclosing the whole set of characters, so to test for a
single alphanumeric character you need ‘<tt>[[:alnum:]]</tt>’. Named
character sets can be used alongside other types,
e.g. ‘<tt>[[:alpha:]0-9]</tt>’.
</p>
</dd>
<dt><tt>[^</tt>...<tt>]</tt></dt>
<dt><tt>[!</tt>...<tt>]</tt></dt>
<dd><p>Like <tt>[</tt>...<tt>]</tt>, except that it matches any character which is
not in the given set.
</p>
</dd>
<dt><tt><</tt>[<var>x</var>]<tt>-</tt>[<var>y</var>]<tt>></tt></dt>
<dd><p>Matches any number in the range <var>x</var> to <var>y</var>, inclusive.
Either of the numbers may be omitted to make the range open-ended;
hence ‘<tt><-></tt>’ matches any number. To match individual digits, the
<tt>[</tt>...<tt>]</tt> form is more efficient.
</p>
<p>Be careful when using other wildcards adjacent to patterns of this form;
for example, <tt><0-9>*</tt> will actually match any number whatsoever at the
start of the string, since the ‘<tt><0-9></tt>’ will match the first digit, and
the ‘<tt>*</tt>’ will match any others. This is a trap for the unwary, but is
in fact an inevitable consequence of the rule that the longest possible
match always succeeds. Expressions such as ‘<tt><0-9>[^[:digit:]]*</tt>’ can be
used instead.
</p>
</dd>
<dt><tt>(</tt>...<tt>)</tt></dt>
<dd><p>Matches the enclosed pattern. This is used for grouping.
If the <tt>KSH_GLOB</tt> option is set, then a
‘<tt>@</tt>’, ‘<tt>*</tt>’, ‘<tt>+</tt>’, ‘<tt>?</tt>’ or ‘<tt>!</tt>’ immediately preceding
the ‘<tt>(</tt>’ is treated specially, as detailed below. The option
<tt>SH_GLOB</tt> prevents bare parentheses from being used in this way, though
the <tt>KSH_GLOB</tt> option is still available.
</p>
<p>Note that grouping cannot extend over multiple directories: it is an error
to have a ‘<tt>/</tt>’ within a group (this only applies for patterns used in
filename generation). There is one exception: a group of the form
<tt>(</tt><var>pat</var><tt>/)#</tt> appearing as a complete path segment can
match a sequence of directories. For example, <tt>foo/(a*/)#bar</tt> matches
<tt>foo/bar</tt>, <tt>foo/any/bar</tt>, <tt>foo/any/anyother/bar</tt>, and so on.
</p>
</dd>
<dt><var>x</var><tt>|</tt><var>y</var></dt>
<dd><p>Matches either <var>x</var> or <var>y</var>.
This operator has lower precedence than any other.
The ‘<tt>|</tt>’ character
must be within parentheses, to avoid interpretation as a pipeline.
</p>
</dd>
<dt><tt>^</tt><var>x</var></dt>
<dd><p>(Requires <tt>EXTENDED_GLOB</tt> to be set.)
Matches anything except the pattern <var>x</var>.
This has a higher precedence than ‘<tt>/</tt>’, so ‘<tt>^foo/bar</tt>’
will search directories in ‘<tt>.</tt>’ except ‘<tt>./foo</tt>’
for a file named ‘<tt>bar</tt>’.
</p>
</dd>
<dt><var>x</var><tt>~</tt><var>y</var></dt>
<dd><p>(Requires <tt>EXTENDED_GLOB</tt> to be set.)
Match anything that matches the pattern <var>x</var> but does not match <var>y</var>.
This has lower precedence than any operator except ‘<tt>|</tt>’, so
‘<tt>*/*~foo/bar</tt>’ will search for all files in all directories in ‘<tt>.</tt>’
and then exclude ‘<tt>foo/bar</tt>’ if there was such a match.
Multiple patterns can be excluded by
‘<var>foo</var><tt>~</tt><var>bar</var><tt>~</tt><var>baz</var>’.
In the exclusion pattern (<var>y</var>), ‘<tt>/</tt>’ and ‘<tt>.</tt>’ are not treated
specially the way they usually are in globbing.
</p>
</dd>
<dt><var>x</var><tt>#</tt></dt>
<dd><p>(Requires <tt>EXTENDED_GLOB</tt> to be set.)
Matches zero or more occurrences of the pattern <var>x</var>.
This operator has high precedence; ‘<tt>12#</tt>’ is equivalent to ‘<tt>1(2#)</tt>’,
rather than ‘<tt>(12)#</tt>’. It is an error for an unquoted ‘<tt>#</tt>’ to follow
something which cannot be repeated; this includes an empty string, a
pattern already followed by ‘<tt>##</tt>’, or parentheses when part of a
<tt>KSH_GLOB</tt> pattern (for example, ‘<tt>!(</tt><var>foo</var><tt>)#</tt>’ is
invalid and must be replaced by
‘<tt>*(!(</tt><var>foo</var><tt>))</tt>’).
</p>
</dd>
<dt><var>x</var><tt>##</tt></dt>
<dd><p>(Requires <tt>EXTENDED_GLOB</tt> to be set.)
Matches one or more occurrences of the pattern <var>x</var>.
This operator has high precedence; ‘<tt>12##</tt>’ is equivalent to ‘<tt>1(2##)</tt>’,
rather than ‘<tt>(12)##</tt>’. No more than two active ‘<tt>#</tt>’ characters may
appear together. (Note the potential clash with glob qualifiers in the
form ‘<tt>1(2##)</tt>’ which should therefore be avoided.)
</p>
</dd>
</dl>
<hr>
<a name="ksh_002dlike-Glob-Operators"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Glob-Operators" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Precedence" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.2 ksh-like Glob Operators</h3>
<p><a name="index-KSH_005fGLOB_002c-use-of"></a>
If the <tt>KSH_GLOB</tt> option is set, the effects of parentheses can be
modified by a preceding ‘<tt>@</tt>’, ‘<tt>*</tt>’, ‘<tt>+</tt>’, ‘<tt>?</tt>’ or ‘<tt>!</tt>’.
This character need not be unquoted to have special effects,
but the ‘<tt>(</tt>’ must be.
</p>
<dl compact="compact">
<dt><tt>@(</tt>...<tt>)</tt></dt>
<dd><p>Match the pattern in the parentheses. (Like ‘<tt>(</tt>...<tt>)</tt>’.)
</p>
</dd>
<dt><tt>*(</tt>...<tt>)</tt></dt>
<dd><p>Match any number of occurrences. (Like ‘<tt>(</tt>...<tt>)#</tt>’,
except that recursive directory searching is not supported.)
</p>
</dd>
<dt><tt>+(</tt>...<tt>)</tt></dt>
<dd><p>Match at least one occurrence. (Like ‘<tt>(</tt>...<tt>)##</tt>’,
except that recursive directory searching is not supported.)
</p>
</dd>
<dt><tt>?(</tt>...<tt>)</tt></dt>
<dd><p>Match zero or one occurrence. (Like ‘<tt>(|</tt>...<tt>)</tt>’.)
</p>
</dd>
<dt><tt>!(</tt>...<tt>)</tt></dt>
<dd><p>Match anything but the expression in parentheses.
(Like ‘<tt>(^(</tt>...<tt>))</tt>’.)
</p>
</dd>
</dl>
<hr>
<a name="Precedence"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#ksh_002dlike-Glob-Operators" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Globbing-Flags" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.3 Precedence</h3>
<p><a name="index-precedence-of-glob-operators"></a>
The precedence of the operators given above is (highest) ‘<tt>^</tt>’, ‘<tt>/</tt>’,
‘<tt>~</tt>’, ‘<tt>|</tt>’ (lowest); the
remaining operators are simply treated from left to right as part of a
string, with ‘<tt>#</tt>’ and ‘<tt>##</tt>’ applying to the shortest possible
preceding unit (i.e. a character, ‘<tt>?</tt>’, ‘<tt>[</tt>...<tt>]</tt>’,
‘<tt><</tt>...<tt>></tt>’, or a parenthesised expression). As mentioned
above, a ‘<tt>/</tt>’ used as a directory separator may not appear inside
parentheses, while a ‘<tt>|</tt>’ must do so; in patterns used in other contexts
than filename generation (for example, in <tt>case</tt> statements and tests
within ‘<tt>[[</tt>...<tt>]]</tt>’), a ‘<tt>/</tt>’ is not special; and ‘<tt>/</tt>’ is also
not special after a ‘<tt>~</tt>’ appearing outside parentheses in a filename
pattern.
</p>
<hr>
<a name="Globbing-Flags"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Precedence" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Approximate-Matching" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.4 Globbing Flags</h3>
<p>There are various flags which affect any text to their right up to the
end of the enclosing group or to the end of the pattern; they require
the <tt>EXTENDED_GLOB</tt> option. All take the form
<tt>(#</tt><var>X</var><tt>)</tt> where <var>X</var> may have one of the following
forms:
</p>
<dl compact="compact">
<dt><tt>i</tt></dt>
<dd><p>Case insensitive: upper or lower case characters in the pattern match
upper or lower case characters.
</p>
</dd>
<dt><tt>l</tt></dt>
<dd><p>Lower case characters in the pattern match upper or lower case
characters; upper case characters in the pattern still only match
upper case characters.
</p>
</dd>
<dt><tt>I</tt></dt>
<dd><p>Case sensitive: locally negates the effect of <tt>i</tt> or <tt>l</tt> from
that point on.
</p>
<a name="index-match"></a>
<a name="index-mbegin"></a>
<a name="index-mend"></a>
</dd>
<dt><tt>b</tt></dt>
<dd><p>Activate backreferences for parenthesised groups in the pattern;
this does not work in filename generation. When a pattern with a set of
active parentheses is matched, the strings matched by the groups are
stored in the array <tt>$match</tt>, the indices of the beginning of the matched
parentheses in the array <tt>$mbegin</tt>, and the indices of the end in the array
<tt>$mend</tt>, with the first element of each array corresponding to the first
parenthesised group, and so on. These arrays are not otherwise special to
the shell. The indices use the same convention as does parameter
substitution, so that elements of <tt>$mend</tt> and <tt>$mbegin</tt> may be used in
subscripts; the <tt>KSH_ARRAYS</tt> option is respected. Sets of globbing flags
are not considered parenthesised groups; only the first nine active
parentheses can be referenced.
</p>
<p>For example,
</p>
<div class="example">
<pre class="example">foo="a string with a message"
if [[ $foo = (a|an)' '(#b)(*)' '* ]]; then
print ${foo[$mbegin[1],$mend[1]]}
fi
</pre></div>
<p>prints ‘<tt>string with a</tt>’. Note that the first parenthesis is before the
<tt>(#b)</tt> and does not create a backreference.
</p>
<p>Backreferences work with all forms of pattern matching other than filename
generation, but note that when performing matches on an entire array, such
as <tt>${</tt><var>array</var><tt>#</tt><var>pattern</var><tt>}</tt>, or a global substitution, such
as <tt>${</tt><var>param</var><tt>//</tt><var>pat</var><tt>/</tt><var>repl</var><tt>}</tt>, only the data for the
last match remains available. In the case of global replacements this may
still be useful. See the example for the <tt>m</tt> flag below.
</p>
<p>The numbering of backreferences strictly follows the order of the opening
parentheses from left to right in the pattern string, although sets of
parentheses may be nested. There are special rules for parentheses followed
by ‘<tt>#</tt>’ or ‘<tt>##</tt>’. Only the last match of the parenthesis is
remembered: for example, in ‘<tt>[[ abab = (#b)([ab])# ]]</tt>’, only the final
‘<tt>b</tt>’ is stored in <tt>match[1]</tt>. Thus extra parentheses may be necessary
to match the complete segment: for example, use
‘<tt>X((ab|cd)#)Y</tt>’ to match
a whole string of either ‘<tt>ab</tt>’ or ‘<tt>cd</tt>’ between ‘<tt>X</tt>’ and ‘<tt>Y</tt>’,
using the value of <tt>$match[1]</tt> rather than <tt>$match[2]</tt>.
</p>
<p>If the match fails none of the parameters is altered, so in some cases it
may be necessary to initialise them beforehand. If some of the
backreferences fail to match — which happens if they are in an alternate
branch which fails to match, or if they are followed by <tt>#</tt> and matched
zero times — then the matched string is set to the empty string, and the
start and end indices are set to -1.
</p>
<p>Pattern matching with backreferences is slightly slower than without.
</p>
</dd>
<dt><tt>B</tt></dt>
<dd><p>Deactivate backreferences, negating the effect of the <tt>b</tt> flag from that
point on.
</p>
</dd>
<dt><tt>c</tt><var>N</var><tt>,</tt><var>M</var></dt>
<dd><p>The flag <tt>(#c</tt><var>N</var><tt>,</tt><var>M</var><tt>)</tt> can be used anywhere
that the <tt>#</tt> or <tt>##</tt> operators can be used except in the expressions
‘<tt>(*/)#</tt>’ and ‘<tt>(*/)##</tt>’ in filename generation, where ‘<tt>/</tt>’
has special meaning; it cannot be combined with other globbing flags and
a bad pattern error occurs if it is misplaced. It is equivalent to the
form <tt>{</tt><var>N</var><tt>,</tt><var>M</var><tt>}</tt> in regular expressions. The previous
character or group is required to match between <var>N</var> and <var>M</var> times,
inclusive. The form <tt>(#c</tt><var>N</var><tt>)</tt> requires exactly <tt>N</tt>
matches; <tt>(#c,</tt><var>M</var><tt>)</tt> is equivalent to specifying <var>N</var>
as 0; <tt>(#c</tt><var>N</var><tt>,)</tt> specifies that there is no maximum
limit on the number of matches.
</p>
<a name="index-MATCH"></a>
<a name="index-MBEGIN"></a>
<a name="index-MEND"></a>
</dd>
<dt><tt>m</tt></dt>
<dd><p>Set references to the match data for the entire string matched; this is
similar to backreferencing and does not work in filename generation. The
flag must be in effect at the end of the pattern, i.e. not local to a
group. The parameters <tt>$MATCH</tt>, <tt>$MBEGIN</tt> and <tt>$MEND</tt> will be set to
the string matched and to the indices of the beginning and end of the
string, respectively. This is most useful in parameter substitutions, as
otherwise the string matched is obvious.
</p>
<p>For example,
</p>
<div class="example">
<pre class="example">arr=(veldt jynx grimps waqf zho buck)
print ${arr//(#m)[aeiou]/${(U)MATCH}}
</pre></div>
<p>forces all the matches (i.e. all vowels) into uppercase, printing
‘<tt>vEldt jynx grImps wAqf zhO bUck</tt>’.
</p>
<p>Unlike backreferences, there is no speed penalty for using match
references, other than the extra substitutions required for the
replacement strings in cases such as the example shown.
</p>
</dd>
<dt><tt>M</tt></dt>
<dd><p>Deactivate the <tt>m</tt> flag, hence no references to match data will be
created.
</p>
</dd>
<dt><tt>a</tt><var>num</var></dt>
<dd><p>Approximate matching: <var>num</var> errors are allowed in the string matched by
the pattern. The rules for this are described in the next subsection.
</p>
</dd>
<dt><tt>s</tt>, <tt>e</tt></dt>
<dd><p>Unlike the other flags, these have only a local effect, and each must
appear on its own: ‘<tt>(#s)</tt>’ and ‘<tt>(#e)</tt>’ are the only valid forms.
The ‘<tt>(#s)</tt>’ flag succeeds only at the start of the test string, and the
‘<tt>(#e)</tt>’ flag succeeds only at the end of the test string; they
correspond to ‘<tt>^</tt>’ and ‘<tt>$</tt>’ in standard regular expressions. They
are useful for matching path segments in patterns other than those in
filename generation (where path segments are in any case treated
separately). For example, ‘<tt>*((#s)|/)test((#e)|/)*</tt>’ matches
a path segment ‘<tt>test</tt>’ in any of the following strings: <tt>test</tt>,
<tt>test/at/start</tt>, <tt>at/end/test</tt>, <tt>in/test/middle</tt>.
</p>
<p>Another use is in parameter substitution; for example
‘<tt>${array/(#s)A*Z(#e)}</tt>’ will remove only elements of an
array which
match the complete pattern ‘<tt>A*Z</tt>’. There are other ways of performing
many operations of this type, however the combination of the substitution
operations ‘<tt>/</tt>’ and ‘<tt>//</tt>’ with the ‘<tt>(#s)</tt>’ and ‘<tt>(#e)</tt>’ flags
provides a single simple and memorable method.
</p>
<p>Note that assertions of the form ‘<tt>(^(#s))</tt>’ also work, i.e. match
anywhere except at the start of the string, although this actually means
‘anything except a zero-length portion at the start of the string’; you
need to use ‘<tt>(""~(#s))</tt>’ to match a zero-length portion of the string
not at the start.
</p>
</dd>
<dt><tt>q</tt></dt>
<dd><p>A ‘<tt>q</tt>’ and everything up to the closing parenthesis of the globbing
flags are ignored by the pattern matching code. This is intended to
support the use of glob qualifiers, see below. The result is that
the pattern ‘<tt>(#b)(*).c(#q.)</tt>’ can be used both for globbing
and for
matching against a string. In the former case, the ‘<tt>(#q.)</tt>’ will be
treated as a glob qualifier and the ‘<tt>(#b)</tt>’ will not be useful, while in
the latter case the ‘<tt>(#b)</tt>’ is useful for backreferences and the
‘<tt>(#q.)</tt>’ will be ignored. Note that colon modifiers in the glob
qualifiers are also not applied in ordinary pattern matching.
</p>
</dd>
<dt><tt>u</tt></dt>
<dd><p>Respect the current locale in determining the presence of multibyte
characters in a pattern, provided the shell was compiled with
<tt>MULTIBYTE_SUPPORT</tt>. This overrides the <tt>MULTIBYTE</tt>
option; the default behaviour is taken from the option. Compare <tt>U</tt>.
(Mnemonic: typically multibyte characters are from Unicode in the UTF-8
encoding, although any extension of ASCII supported by the system
library may be used.)
</p>
</dd>
<dt><tt>U</tt></dt>
<dd><p>All characters are considered to be a single byte long. The opposite
of <tt>u</tt>. This overrides the <tt>MULTIBYTE</tt> option.
</p>
</dd>
</dl>
<p>For example, the test string <tt>fooxx</tt> can be matched by the pattern
<tt>(#i</tt><tt>)FOOXX</tt>, but not by <tt>(#l</tt><tt>)FOOXX</tt>,
<tt>(#i</tt><tt>)FOO</tt><tt>(#I</tt><tt>)XX</tt> or
<tt>((#i</tt><tt>)FOOX</tt><tt>)X</tt>. The string
<tt>(#ia2</tt><tt>)readme</tt> specifies case-insensitive matching of
<tt>readme</tt> with up to two errors.
</p>
<p>When using the ksh syntax for grouping both <tt>KSH_GLOB</tt> and
<tt>EXTENDED_GLOB</tt> must be set and the left parenthesis should be
preceded by <tt>@</tt>. Note also that the flags do not affect letters
inside <tt>[</tt>...<tt>]</tt> groups, in other words <tt>(#i</tt><tt>)[a-z]</tt>
still matches only lowercase letters. Finally, note that when
examining whole paths case-insensitively every directory must be
searched for all files which match, so that a pattern of the form
<tt>(#i</tt><tt>)/foo/bar/...</tt> is potentially slow.
</p>
<hr>
<a name="Approximate-Matching"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Globbing-Flags" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Recursive-Globbing" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.5 Approximate Matching</h3>
<p>When matching approximately, the shell keeps a count of the errors found,
which cannot exceed the number specified in the
<tt>(#a</tt><var>num</var><tt>)</tt> flags. Four types of error are recognised:
</p>
<dl compact="compact">
<dt>1.</dt>
<dd><p>Different characters, as in <tt>fooxbar</tt> and <tt>fooybar</tt>.
</p>
</dd>
<dt>2.</dt>
<dd><p>Transposition of characters, as in <tt>banana</tt> and <tt>abnana</tt>.
</p>
</dd>
<dt>3.</dt>
<dd><p>A character missing in the target string, as with the pattern <tt>road</tt> and
target string <tt>rod</tt>.
</p>
</dd>
<dt>4.</dt>
<dd><p>An extra character appearing in the target string, as with <tt>stove</tt>
and <tt>strove</tt>.
</p>
</dd>
</dl>
<p>Thus, the pattern <tt>(#a3</tt><tt>)abcd</tt> matches <tt>dcba</tt>, with the
errors occurring by using the first rule twice and the second once,
grouping the string as <tt>[d][cb][a]</tt> and <tt>[a][bc][d]</tt>.
</p>
<p>Non-literal parts of the pattern must match exactly, including characters
in character ranges: hence <tt>(#a1</tt><tt>)???</tt> matches strings of
length four, by applying rule 4 to an empty part of the pattern, but not
strings of length two, since all the <tt>?</tt> must match. Other characters
which must match exactly are initial dots in filenames (unless the
<tt>GLOB_DOTS</tt> option is set), and all slashes in filenames, so that
<tt>a/bc</tt> is two errors from <tt>ab/c</tt> (the slash cannot be transposed with
another character). Similarly, errors are counted separately for
non-contiguous strings in the pattern, so that <tt>(ab|cd</tt><tt>)ef</tt>
is two errors from <tt>aebf</tt>.
</p>
<p>When using exclusion via the <tt>~</tt> operator, approximate matching is
treated entirely separately for the excluded part and must be activated
separately. Thus, <tt>(#a1</tt><tt>)README~READ_ME</tt> matches
<tt>READ.ME</tt> but not <tt>READ_ME</tt>, as the trailing <tt>READ_ME</tt> is matched
without approximation. However,
<tt>(#a1</tt><tt>)README~(#a1</tt><tt>)READ_ME</tt>
does not match any pattern of the form <tt>READ</tt><var>?</var><tt>ME</tt> as all
such forms are now excluded.
</p>
<p>Apart from exclusions, there is only one overall error count; however, the
maximum errors allowed may be altered locally, and this can be delimited by
grouping. For example,
<tt>(#a1</tt><tt>)cat</tt><tt>((#a0</tt><tt>)dog</tt><tt>)fox</tt>
allows one error in total, which may not occur in the <tt>dog</tt> section, and
the pattern
<tt>(#a1</tt><tt>)cat</tt><tt>(#a0</tt><tt>)dog</tt><tt>(#a1</tt><tt>)fox</tt>
is equivalent. Note that the point at which an error is first found is the
crucial one for establishing whether to use approximation; for example,
<tt>(#a1)abc(#a0)xyz</tt> will not match <tt>abcdxyz</tt>, because the
error occurs at the ‘<tt>x</tt>’, where approximation is turned off.
</p>
<p>Entire path segments may be matched approximately, so that
‘<tt>(#a1)/foo/d/is/available/at/the/bar</tt>’ allows one error in any path
segment. This is much less efficient than without the <tt>(#a1)</tt>, however,
since every directory in the path must be scanned for a possible
approximate match. It is best to place the <tt>(#a1)</tt> after any path
segments which are known to be correct.
</p>
<hr>
<a name="Recursive-Globbing"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Approximate-Matching" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="#Glob-Qualifiers" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.6 Recursive Globbing</h3>
<p>A pathname component of the form ‘<tt>(</tt><var>foo</var><tt>/)#</tt>’
matches a path consisting of zero or more directories
matching the pattern <var>foo</var>.
</p>
<p>As a shorthand, ‘<tt>**/</tt>’ is equivalent to ‘<tt>(*/)#</tt>’; note that this
therefore matches files in the current directory as well as
subdirectories.
Thus:
</p>
<div class="example">
<pre class="example">ls (*/)#bar
</pre></div>
<p>or
</p>
<div class="example">
<pre class="example">ls **/bar
</pre></div>
<p>does a recursive directory search for files named ‘<tt>bar</tt>’ (potentially
including the file ‘<tt>bar</tt>’ in the current directory). This form does not
follow symbolic links; the alternative form ‘<tt>***/</tt>’ does, but is
otherwise identical. Neither of these can be combined with other forms of
globbing within the same path segment; in that case, the ‘<tt>*</tt>’
operators revert to their usual effect.
</p>
<p>Even shorter forms are available when the option <tt>GLOB_STAR_SHORT</tt> is
set. In that case if no <tt>/</tt> immediately follows a <tt>**</tt> or <tt>***</tt>
they are treated as if both a <tt>/</tt> plus a further <tt>*</tt> are present.
Hence:
</p>
<div class="example">
<pre class="example">setopt GLOBSTARSHORT
ls **.c
</pre></div>
<p>is equivalent to
</p>
<div class="example">
<pre class="example">ls **/*.c
</pre></div>
<hr>
<a name="Glob-Qualifiers"></a>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="#Recursive-Globbing" title="Previous section in reading order"> < </a>]</td>
<td valign="middle" align="left">[<a href="#Filename-Generation" title="Up section"> Up </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next section in reading order"> > </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<h3 class="subsection">14.8.7 Glob Qualifiers</h3>
<p><a name="index-globbing_002c-qualifiers"></a>
<a name="index-qualifiers_002c-globbing"></a>
Patterns used for filename generation may end in a
list of qualifiers enclosed in parentheses.
The qualifiers specify which filenames that otherwise match the given pattern
will be inserted in the argument list.
</p>
<p><a name="index-BARE_005fGLOB_005fQUAL_002c-use-of"></a>
If the option <tt>BARE_GLOB_QUAL</tt> is set, then a trailing set of parentheses
containing no ‘<tt>|</tt>’ or ‘<tt>(</tt>’ characters (or ‘<tt>~</tt>’ if it is special)
is taken as a set of
glob qualifiers. A glob subexpression that would normally be taken as glob
qualifiers, for example ‘<tt>(^x)</tt>’, can be forced to be treated as part of
the glob pattern by doubling the parentheses, in this case producing
‘<tt>((^x))</tt>’.
</p>
<p>If the option <tt>EXTENDED_GLOB</tt> is set, a different syntax for glob
qualifiers is available, namely ‘<tt>(#q</tt><var>x</var><tt>)</tt>’
where <var>x</var> is any of the same
glob qualifiers used in the other format. The qualifiers must still appear
at the end of the pattern. However, with this syntax multiple glob
qualifiers may be chained together. They are treated as a logical AND of
the individual sets of flags. Also, as the syntax is unambiguous, the
expression will be treated as glob qualifiers just as long any parentheses
contained within it are balanced; appearance of ‘<tt>|</tt>’, ‘<tt>(</tt>’ or
‘<tt>~</tt>’ does not negate the effect. Note that qualifiers will be
recognised in this form even if a bare glob qualifier exists at the end of
the pattern, for example ‘<tt>*(#q*)(.)</tt>’ will recognise executable regular
files if both options are set; however, mixed syntax should probably be
avoided for the sake of clarity. Note that within conditions using the
‘<tt>[[</tt>’ form the presence of a parenthesised expression
<tt>(#q</tt><var>...</var><tt>)</tt> at the end of a string indicates that globbing
should be performed; the expression may include glob qualifiers, but
it is also valid if it is simply <tt>(#q)</tt>. This does
not apply to the right hand side of pattern match operators as the
syntax already has special significance.
</p>
<p>A qualifier may be any one of the following:
</p>
<dl compact="compact">
<dt><tt>/</tt></dt>
<dd><p>directories
</p>
</dd>
<dt><tt>F</tt></dt>
<dd><p>‘full’ (i.e. non-empty) directories. Note that the
opposite sense <tt>(^F</tt><tt>)</tt> expands to empty directories
and all non-directories. Use <tt>(/^F</tt><tt>)</tt> for
empty directories.
</p>
</dd>
<dt><tt>.</tt></dt>
<dd><p>plain files
</p>
</dd>
<dt><tt>@</tt></dt>
<dd><p>symbolic links
</p>
</dd>
<dt><tt>=</tt></dt>
<dd><p>sockets
</p>
</dd>
<dt><tt>p</tt></dt>
<dd><p>named pipes (FIFOs)
</p>
</dd>
<dt><tt>*</tt></dt>
<dd><p>executable plain files (0100 or 0010 or 0001)
</p>
</dd>
<dt><tt>%</tt></dt>
<dd><p>device files (character or block special)
</p>
</dd>
<dt><tt>%b</tt></dt>
<dd><p>block special files
</p>
</dd>
<dt><tt>%c</tt></dt>
<dd><p>character special files
</p>
</dd>
<dt><tt>r</tt></dt>
<dd><p>owner-readable files (0400)
</p>
</dd>
<dt><tt>w</tt></dt>
<dd><p>owner-writable files (0200)
</p>
</dd>
<dt><tt>x</tt></dt>
<dd><p>owner-executable files (0100)
</p>
</dd>
<dt><tt>A</tt></dt>
<dd><p>group-readable files (0040)
</p>
</dd>
<dt><tt>I</tt></dt>
<dd><p>group-writable files (0020)
</p>
</dd>
<dt><tt>E</tt></dt>
<dd><p>group-executable files (0010)
</p>
</dd>
<dt><tt>R</tt></dt>
<dd><p>world-readable files (0004)
</p>
</dd>
<dt><tt>W</tt></dt>
<dd><p>world-writable files (0002)
</p>
</dd>
<dt><tt>X</tt></dt>
<dd><p>world-executable files (0001)
</p>
</dd>
<dt><tt>s</tt></dt>
<dd><p>setuid files (04000)
</p>
</dd>
<dt><tt>S</tt></dt>
<dd><p>setgid files (02000)
</p>
</dd>
<dt><tt>t</tt></dt>
<dd><p>files with the sticky bit (01000)
</p>
</dd>
<dt><tt>f</tt><var>spec</var></dt>
<dd><p>files with access rights matching <var>spec</var>. This <var>spec</var> may be a
octal number optionally preceded by a ‘<tt>=</tt>’, a ‘<tt>+</tt>’, or a
‘<tt>-</tt>’. If none of these characters is given, the behavior is the
same as for ‘<tt>=</tt>’. The octal number describes the mode bits to be
expected, if combined with a ‘<tt>=</tt>’, the value given must match the
file-modes exactly, with a ‘<tt>+</tt>’, at least the bits in the
given number must be set in the file-modes, and with a ‘<tt>-</tt>’, the
bits in the number must not be set. Giving a ‘<tt>?</tt>’ instead of a
octal digit anywhere in the number ensures that the corresponding bits
in the file-modes are not checked, this is only useful in combination
with ‘<tt>=</tt>’.
</p>
<p>If the qualifier ‘<tt>f</tt>’ is followed by any other character anything
up to the next matching character (‘<tt>[</tt>’, ‘<tt>{</tt>’, and ‘<tt><</tt>’ match
‘<tt>]</tt>’, ‘<tt>}</tt>’, and ‘<tt>></tt>’ respectively, any other character
matches itself) is taken as a list of comma-separated
<var>sub-spec</var>s. Each <var>sub-spec</var> may be either an octal number as
described above or a list of any of the characters ‘<tt>u</tt>’, ‘<tt>g</tt>’,
‘<tt>o</tt>’, and ‘<tt>a</tt>’, followed by a ‘<tt>=</tt>’, a ‘<tt>+</tt>’, or a
‘<tt>-</tt>’, followed by a list of any of the characters ‘<tt>r</tt>’, ‘<tt>w</tt>’,
‘<tt>x</tt>’, ‘<tt>s</tt>’, and ‘<tt>t</tt>’, or an octal digit. The first list of
characters specify which access rights are to be checked. If a ‘<tt>u</tt>’
is given, those for the owner of the file are used, if a ‘<tt>g</tt>’ is
given, those of the group are checked, a ‘<tt>o</tt>’ means to test those
of other users, and the ‘<tt>a</tt>’ says to test all three groups. The
‘<tt>=</tt>’, ‘<tt>+</tt>’, and ‘<tt>-</tt>’ again says how the modes are to be
checked and have the same meaning as described for the first form
above. The second list of characters finally says which access rights
are to be expected: ‘<tt>r</tt>’ for read access, ‘<tt>w</tt>’ for write access,
‘<tt>x</tt>’ for the right to execute the file (or to search a directory),
‘<tt>s</tt>’ for the setuid and setgid bits, and ‘<tt>t</tt>’ for the sticky
bit.
</p>
<p>Thus, ‘<tt>*(f70?)</tt>’ gives the files for which the owner has read,
write, and execute permission, and for which other group members have
no rights, independent of the permissions for other users. The pattern
‘<tt>*(f-100)</tt>’ gives all files for which the owner does not have
execute permission, and ‘<tt>*(f:gu+w,o-rx:)</tt>’ gives the files for which
the owner and the other members of the group have at least write
permission, and for which other users don’t have read or execute
permission.
</p>
</dd>
<dt><tt>e</tt><var>string</var></dt>
<dt><tt>+</tt><var>cmd</var></dt>
<dd><p>The <var>string</var> will be executed as shell code. The filename will be
included in the list if and only if the code returns a zero status (usually
the status of the last command).
</p>
<p>In the first form, the first character after the ‘<tt>e</tt>’
will be used as a separator and anything up to the next matching separator
will be taken as the <var>string</var>; ‘<tt>[</tt>’, ‘<tt>{</tt>’, and ‘<tt><</tt>’ match
‘<tt>]</tt>’, ‘<tt>}</tt>’, and ‘<tt>></tt>’, respectively, while any other character
matches itself. Note that expansions must be quoted in the <var>string</var>
to prevent them from being expanded before globbing is done.
<var>string</var> is then executed as shell code. The string <tt>globqual</tt>
is appended to the array <tt>zsh_eval_context</tt> the duration of
execution.
</p>
<p><a name="index-REPLY_002c-use-of-1"></a>
<a name="index-reply_002c-use-of"></a>
During the execution of <var>string</var> the filename currently being tested is
available in the parameter <tt>REPLY</tt>; the parameter may be altered to
a string to be inserted into the list instead of the original
filename. In addition, the parameter <tt>reply</tt> may be set to an array or a
string, which overrides the value of <tt>REPLY</tt>. If set to an array, the
latter is inserted into the command line word by word.
</p>
<p>For example, suppose a directory contains a single file ‘<tt>lonely</tt>’. Then
the expression ‘<tt>*(e:'reply=(${REPLY}{1,2})':)</tt>’ will cause the words
‘<tt>lonely1</tt>’ and ‘<tt>lonely2</tt>’ to be inserted into the command line. Note
the quoting of <var>string</var>.
</p>
<p>The form <tt>+</tt><var>cmd</var> has the same effect, but no delimiters appear
around <var>cmd</var>. Instead, <var>cmd</var> is taken as the longest sequence of
characters following the <tt>+</tt> that are alphanumeric or underscore.
Typically <var>cmd</var> will be the name of a shell function that contains the
appropriate test. For example,
</p>
<div class="example">
<pre class="example">nt() { [[ $REPLY -nt $NTREF ]] }
NTREF=reffile
ls -l *(+nt)
</pre></div>
<p>lists all files in the directory that have been modified more recently than
<tt>reffile</tt>.
</p>
</dd>
<dt><tt>d</tt><var>dev</var></dt>
<dd><p>files on the device <var>dev</var>
</p>
</dd>
<dt><tt>l</tt>[<tt>-</tt>|<tt>+</tt>]<var>ct</var></dt>
<dd><p>files having a link count less than <var>ct</var> (<tt>-</tt>), greater than
<var>ct</var> (<tt>+</tt>), or equal to <var>ct</var>
</p>
</dd>
<dt><tt>U</tt></dt>
<dd><p>files owned by the effective user ID
</p>
</dd>
<dt><tt>G</tt></dt>
<dd><p>files owned by the effective group ID
</p>
</dd>
<dt><tt>u</tt><var>id</var></dt>
<dd><p>files owned by user ID <var>id</var> if that is a number. Otherwise,
<var>id</var> specifies a user name: the
character after the ‘<tt>u</tt>’ will be taken as a separator and the string
between it and the next matching separator will be taken as a user name.
The starting separators ‘<tt>[</tt>’, ‘<tt>{</tt>’, and ‘<tt><</tt>’
match the final separators ‘<tt>]</tt>’, ‘<tt>}</tt>’, and ‘<tt>></tt>’, respectively;
any other character matches itself. The selected files are those
owned by this user. For example, ‘<tt>u:foo:</tt>’ or ‘<tt>u[foo]</tt>’ selects
files owned by user ‘<tt>foo</tt>’.
</p>
</dd>
<dt><tt>g</tt><var>id</var></dt>
<dd><p>like <tt>u</tt><var>id</var> but with group IDs or names
</p>
</dd>
<dt><tt>a</tt>[<tt>Mwhms</tt>][<tt>-</tt>|<tt>+</tt>]<var>n</var></dt>
<dd><p>files accessed exactly <var>n</var> days ago. Files accessed within the last
<var>n</var> days are selected using a negative value for <var>n</var> (<tt>-</tt><var>n</var>).
Files accessed more than <var>n</var> days ago are selected by a positive <var>n</var>
value (<tt>+</tt><var>n</var>). Optional unit specifiers ‘<tt>M</tt>’, ‘<tt>w</tt>’,
‘<tt>h</tt>’, ‘<tt>m</tt>’ or ‘<tt>s</tt>’ (e.g. ‘<tt>ah5</tt>’) cause the check to be
performed with months (of 30 days), weeks, hours, minutes or seconds
instead of days, respectively. An explicit ‘<tt>d</tt>’ for days is also
allowed.
</p>
<p>Any fractional part of the difference between the access time and the
current part in the appropriate units is ignored in the comparison. For
instance, ‘<tt>echo *(ah-5)</tt>’ would echo files accessed within the last
five hours, while ‘<tt>echo *(ah+5)</tt>’ would echo files accessed at least
six hours ago, as times strictly between five and six hours are treated
as five hours.
</p>
</dd>
<dt><tt>m</tt>[<tt>Mwhms</tt>][<tt>-</tt>|<tt>+</tt>]<var>n</var></dt>
<dd><p>like the file access qualifier, except that it uses the file modification
time.
</p>
</dd>
<dt><tt>c</tt>[<tt>Mwhms</tt>][<tt>-</tt>|<tt>+</tt>]<var>n</var></dt>
<dd><p>like the file access qualifier, except that it uses the file inode change
time.
</p>
</dd>
<dt><tt>L</tt>[<tt>+</tt>|<tt>-</tt>]<var>n</var></dt>
<dd><p>files less than <var>n</var> bytes (<tt>-</tt>), more than <var>n</var> bytes (<tt>+</tt>), or
exactly <var>n</var> bytes in length.
</p>
<p>If this flag is directly followed by a <em>size specifier</em> ‘<tt>k</tt>’ (‘<tt>K</tt>’),
‘<tt>m</tt>’ (‘<tt>M</tt>’), or ‘<tt>p</tt>’ (‘<tt>P</tt>’) (e.g. ‘<tt>Lk-50</tt>’) the check is
performed with kilobytes, megabytes, or blocks (of 512 bytes) instead.
(On some systems additional specifiers are available for gigabytes,
‘<tt>g</tt>’ or ‘<tt>G</tt>’, and terabytes, ‘<tt>t</tt>’ or ‘<tt>T</tt>’.) If a size specifier
is used a file is regarded as "exactly" the size if the file size rounded up
to the next unit is equal to the test size. Hence ‘<tt>*(Lm1)</tt>’
matches files from 1 byte up to 1 Megabyte inclusive. Note also that
the set of files "less than" the test size only includes files that would
not match the equality test; hence ‘<tt>*(Lm-1)</tt>’ only matches
files of zero size.
</p>
</dd>
<dt><tt>^</tt></dt>
<dd><p>negates all qualifiers following it
</p>
</dd>
<dt><tt>-</tt></dt>
<dd><p>toggles between making the qualifiers work on symbolic links (the
default) and the files they point to
</p>
</dd>
<dt><tt>M</tt></dt>
<dd><p>sets the <tt>MARK_DIRS</tt> option for the current pattern
<a name="index-MARK_005fDIRS_002c-setting-in-pattern"></a>
</p>
</dd>
<dt><tt>T</tt></dt>
<dd><p>appends a trailing qualifier mark to the filenames, analogous to the
<tt>LIST_TYPES</tt> option, for the current pattern (overrides <tt>M</tt>)
</p>
</dd>
<dt><tt>N</tt></dt>
<dd><p>sets the <tt>NULL_GLOB</tt> option for the current pattern
<a name="index-NULL_005fGLOB_002c-setting-in-pattern"></a>
</p>
</dd>
<dt><tt>D</tt></dt>
<dd><p>sets the <tt>GLOB_DOTS</tt> option for the current pattern
<a name="index-GLOB_005fDOTS_002c-setting-in-pattern"></a>
</p>
</dd>
<dt><tt>n</tt></dt>
<dd><p>sets the <tt>NUMERIC_GLOB_SORT</tt> option for the current pattern
<a name="index-NUMERIC_005fGLOB_005fSORT_002c-setting-in-pattern"></a>
</p>
</dd>
<dt><tt>Y</tt><var>n</var></dt>
<dd><p>enables short-circuit mode: the pattern will expand to at most <var>n</var>
filenames. If more than <var>n</var> matches exist, only the first <var>n</var>
matches in directory traversal order will be considered.
</p>
<p>Implies <tt>oN</tt> when no <tt>o</tt><var>c</var> qualifier is used.
</p>
</dd>
<dt><tt>o</tt><var>c</var></dt>
<dd><p>specifies how the names of the files should be sorted. If <var>c</var> is
<tt>n</tt> they are sorted by name; if it is <tt>L</tt> they
are sorted depending on the size (length) of the files; if <tt>l</tt>
they are sorted by the number of links; if <tt>a</tt>, <tt>m</tt>, or <tt>c</tt>
they are sorted by the time of the last access, modification, or
inode change respectively; if <tt>d</tt>, files in subdirectories appear before
those in the current directory at each level of the search — this is best
combined with other criteria, for example ‘<tt>odon</tt>’ to sort on names for
files within the same directory; if <tt>N</tt>, no sorting is performed.
Note that <tt>a</tt>, <tt>m</tt>, and <tt>c</tt> compare
the age against the current time, hence the first name in the list is the
youngest file. Also note that the modifiers <tt>^</tt> and <tt>-</tt> are used,
so ‘<tt>*(^-oL)</tt>’ gives a list of all files sorted by file size in descending
order, following any symbolic links. Unless <tt>oN</tt> is used, multiple order
specifiers may occur to resolve ties.
</p>
<p>The default sorting is <tt>n</tt> (by name) unless the <tt>Y</tt> glob qualifier is used,
in which case it is <tt>N</tt> (unsorted).
</p>
<p><tt>oe</tt> and <tt>o+</tt> are special cases; they are each followed by shell code,
delimited as for the <tt>e</tt> glob qualifier and the <tt>+</tt> glob qualifier
respectively (see above). The code is executed for each matched file with
the parameter <tt>REPLY</tt> set to the name of the file on entry and
<tt>globsort</tt> appended to <tt>zsh_eval_context</tt>. The code
should modify the parameter <tt>REPLY</tt> in some fashion. On return, the
value of the parameter is used instead of the file name as the string on
which to sort. Unlike other sort operators, <tt>oe</tt> and <tt>o+</tt> may be
repeated, but note that the maximum number of sort operators of any kind
that may appear in any glob expression is 12.
</p>
</dd>
<dt><tt>O</tt><var>c</var></dt>
<dd><p>like ‘<tt>o</tt>’, but sorts in descending order; i.e. ‘<tt>*(^oc)</tt>’ is the
same as ‘<tt>*(Oc)</tt>’ and ‘<tt>*(^Oc)</tt>’ is the same as ‘<tt>*(oc)</tt>’; ‘<tt>Od</tt>’
puts files in the current directory before those in subdirectories at each
level of the search.
</p>
</dd>
<dt><tt>[</tt><var>beg</var>[<tt>,</tt><var>end</var>]<tt>]</tt></dt>
<dd><p>specifies which of the matched filenames should be included in the
returned list. The syntax is the same as for array
subscripts. <var>beg</var> and the optional <var>end</var> may be mathematical
expressions. As in parameter subscripting they may be negative to make
them count from the last match backward. E.g.: ‘<tt>*(-OL[1,3])</tt>’
gives a list of the names of the three largest files.
</p>
</dd>
<dt><tt>P</tt><var>string</var></dt>
<dd><p>The <var>string</var> will be prepended to each glob match as a separate
word. <var>string</var> is delimited in the same way as arguments to the
<tt>e</tt> glob qualifier described above. The qualifier can be repeated;
the words are prepended separately so that the resulting command
line contains the words in the same order they were given in the
list of glob qualifiers.
</p>
<p>A typical use for this is to prepend an option before all occurrences
of a file name; for example, the pattern ‘<tt>*(P:-f:)</tt>’ produces the
command line arguments ‘<tt>-f</tt> <var>file1</var> <tt>-f</tt> <var>file2</var> ...’
</p>
<p>If the modifier <tt>^</tt> is active, then <var>string</var> will be appended
instead of prepended. Prepending and appending is done independently
so both can be used on the same glob expression; for example by writing
‘<tt>*(P:foo:^P:bar:^P:baz:)</tt>’ which produces the command line arguments
‘<tt>foo</tt> <tt>baz</tt> <var>file1</var> <tt>bar</tt> ...’
</p>
</dd>
</dl>
<p>More than one of these lists can be combined, separated by commas. The
whole list matches if at least one of the sublists matches (they are
‘or’ed, the qualifiers in the sublists are ‘and’ed). Some qualifiers,
however, affect all matches generated, independent of the sublist in
which they are given. These are the qualifiers ‘<tt>M</tt>’, ‘<tt>T</tt>’,
‘<tt>N</tt>’, ‘<tt>D</tt>’, ‘<tt>n</tt>’, ‘<tt>o</tt>’, ‘<tt>O</tt>’ and the subscripts given
in brackets (‘<tt>[</tt><var>...</var><tt>]</tt>’).
</p>
<p>If a ‘<tt>:</tt>’ appears in a qualifier list, the remainder of the expression in
parenthesis is interpreted as a modifier (see <a href="#Modifiers">Modifiers</a>
in <a href="#History-Expansion">History Expansion</a>). Each modifier must be introduced by a
separate ‘<tt>:</tt>’. Note also that the result after modification does not
have to be an existing file. The name of any existing file can be followed
by a modifier of the form ‘<tt>(:</tt><var>...</var><tt>)</tt>’
even if no actual filename generation
is performed, although note that the presence of the parentheses
causes the entire expression to be subjected to any global pattern matching
options such as <tt>NULL_GLOB</tt>. Thus:
</p>
<div class="example">
<pre class="example">ls *(-/)
</pre></div>
<p>lists all directories and symbolic links that point to directories,
and
</p>
<div class="example">
<pre class="example">ls *(-@)
</pre></div>
<p>lists all broken symbolic links, and
</p>
<div class="example">
<pre class="example">ls *(%W)
</pre></div>
<p>lists all world-writable device files in the current directory, and
</p>
<div class="example">
<pre class="example">ls *(W,X)
</pre></div>
<p>lists all files in the current directory that are
world-writable or world-executable, and
</p>
<div class="example">
<pre class="example">echo /tmp/foo*(u0^@:t)
</pre></div>
<p>outputs the basename of all root-owned files beginning with the string
‘<tt>foo</tt>’ in <tt>/tmp</tt>, ignoring symlinks, and
</p>
<div class="example">
<pre class="example">ls *.*~(lex|parse).[ch](^D^l1)
</pre></div>
<p>lists all files having a link count of one whose names contain a dot
(but not those starting with a dot, since <tt>GLOB_DOTS</tt> is explicitly
switched off) except for <tt>lex.c</tt>, <tt>lex.h</tt>, <tt>parse.c</tt> and <tt>parse.h</tt>.
</p>
<div class="example">
<pre class="example">print b*.pro(#q:s/pro/shmo/)(#q.:s/builtin/shmiltin/)
</pre></div>
<p>demonstrates how colon modifiers and other qualifiers may be chained
together. The ordinary qualifier ‘<tt>.</tt>’ is applied first, then the colon
modifiers in order from left to right. So if <tt>EXTENDED_GLOB</tt> is set and
the base pattern matches the regular file <tt>builtin.pro</tt>, the shell will
print ‘<tt>shmiltin.shmo</tt>’.
</p><hr>
<table class="header" cellpadding="1" cellspacing="1" border="0">
<tr><td valign="middle" align="left">[<a href="#Expansion" title="Beginning of this chapter or previous chapter"> << </a>]</td>
<td valign="middle" align="left">[<a href="Parameters.html#Parameters" title="Next chapter"> >> </a>]</td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left"> </td>
<td valign="middle" align="left">[<a href="index.html#Top" title="Cover (top) of document">Top</a>]</td>
<td valign="middle" align="left">[<a href="zsh_toc.html#SEC_Contents" title="Table of contents">Contents</a>]</td>
<td valign="middle" align="left">[<a href="Concept-Index.html#Concept-Index" title="Index">Index</a>]</td>
<td valign="middle" align="left">[<a href="zsh_abt.html#SEC_About" title="About (help)"> ? </a>]</td>
</tr></table>
<p><font size="-1">
This document was generated on <em>April 11, 2017</em> using <a href="http://www.gnu.org/software/texinfo/"><em>texi2any</em></a>.
</font></p>
<font size="-1">Zsh version 5.3.1, released on December 21, 2016.</font>
</body>
</html>
|