This file is indexed.

/usr/share/pyshared/pexpect.py is in python-pexpect 2.4-1.

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
"""Pexpect is a Python module for spawning child applications and controlling
them automatically. Pexpect can be used for automating interactive applications
such as ssh, ftp, passwd, telnet, etc. It can be used to a automate setup
scripts for duplicating software package installations on different servers. It
can be used for automated software testing. Pexpect is in the spirit of Don
Libes' Expect, but Pexpect is pure Python. Other Expect-like modules for Python
require TCL and Expect or require C extensions to be compiled. Pexpect does not
use C, Expect, or TCL extensions. It should work on any platform that supports
the standard Python pty module. The Pexpect interface focuses on ease of use so
that simple tasks are easy.

There are two main interfaces to Pexpect -- the function, run() and the class,
spawn. You can call the run() function to execute a command and return the
output. This is a handy replacement for os.system().

For example::

    pexpect.run('ls -la')

The more powerful interface is the spawn class. You can use this to spawn an
external child command and then interact with the child by sending lines and
expecting responses.

For example::

    child = pexpect.spawn('scp foo myname@host.example.com:.')
    child.expect ('Password:')
    child.sendline (mypassword)

This works even for commands that ask for passwords or other input outside of
the normal stdio streams.

Credits: Noah Spurrier, Richard Holden, Marco Molteni, Kimberley Burchett,
Robert Stone, Hartmut Goebel, Chad Schroeder, Erick Tryzelaar, Dave Kirby, Ids
vander Molen, George Todd, Noel Taylor, Nicolas D. Cesar, Alexander Gattin,
Jacques-Etienne Baudoux, Geoffrey Marshall, Francisco Lourenco, Glen Mabey,
Karthik Gurusamy, Fernando Perez, Corey Minyard, Jon Cohen, Guillaume
Chazarain, Andrew Ryan, Nick Craig-Wood, Andrew Stone, Jorgen Grahn, John
Spiegel, Jan Grant (Let me know if I forgot anyone.)

Free, open source, and all that good stuff.

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
of the Software, and to permit persons to whom the Software is furnished to do
so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

Pexpect Copyright (c) 2008 Noah Spurrier
http://pexpect.sourceforge.net/

$Id: pexpect.py 516 2008-05-23 20:46:01Z noah $
"""

try:
    import os, sys, time
    import select
    import string
    import re
    import struct
    import resource
    import types
    import pty
    import tty
    import termios
    import fcntl
    import errno
    import traceback
    import signal
except ImportError, e:
    raise ImportError (str(e) + """

A critical module was not found. Probably this operating system does not
support it. Pexpect is intended for UNIX-like operating systems.""")

__version__ = '2.4'
__revision__ = '$Revision: 516 $'
__all__ = ['ExceptionPexpect', 'EOF', 'TIMEOUT', 'spawn', 'run', 'which',
    'split_command_line', '__version__', '__revision__']

# Exception classes used by this module.
class ExceptionPexpect(Exception):

    """Base class for all exceptions raised by this module.
    """

    def __init__(self, value):

        self.value = value

    def __str__(self):

        return str(self.value)

    def get_trace(self):

        """This returns an abbreviated stack trace with lines that only concern
        the caller. In other words, the stack trace inside the Pexpect module
        is not included. """

        tblist = traceback.extract_tb(sys.exc_info()[2])
        #tblist = filter(self.__filter_not_pexpect, tblist)
        tblist = [item for item in tblist if self.__filter_not_pexpect(item)]
        tblist = traceback.format_list(tblist)
        return ''.join(tblist)

    def __filter_not_pexpect(self, trace_list_item):

        """This returns True if list item 0 the string 'pexpect.py' in it. """

        if trace_list_item[0].find('pexpect.py') == -1:
            return True
        else:
            return False

class EOF(ExceptionPexpect):

    """Raised when EOF is read from a child. This usually means the child has exited."""

class TIMEOUT(ExceptionPexpect):

    """Raised when a read time exceeds the timeout. """

##class TIMEOUT_PATTERN(TIMEOUT):
##    """Raised when the pattern match time exceeds the timeout.
##    This is different than a read TIMEOUT because the child process may
##    give output, thus never give a TIMEOUT, but the output
##    may never match a pattern.
##    """
##class MAXBUFFER(ExceptionPexpect):
##    """Raised when a scan buffer fills before matching an expected pattern."""

def run (command, timeout=-1, withexitstatus=False, events=None, extra_args=None, logfile=None, cwd=None, env=None):

    """
    This function runs the given command; waits for it to finish; then
    returns all output as a string. STDERR is included in output. If the full
    path to the command is not given then the path is searched.

    Note that lines are terminated by CR/LF (\\r\\n) combination even on
    UNIX-like systems because this is the standard for pseudo ttys. If you set
    'withexitstatus' to true, then run will return a tuple of (command_output,
    exitstatus). If 'withexitstatus' is false then this returns just
    command_output.

    The run() function can often be used instead of creating a spawn instance.
    For example, the following code uses spawn::

        from pexpect import *
        child = spawn('scp foo myname@host.example.com:.')
        child.expect ('(?i)password')
        child.sendline (mypassword)

    The previous code can be replace with the following::

        from pexpect import *
        run ('scp foo myname@host.example.com:.', events={'(?i)password': mypassword})

    Examples
    ========

    Start the apache daemon on the local machine::

        from pexpect import *
        run ("/usr/local/apache/bin/apachectl start")

    Check in a file using SVN::

        from pexpect import *
        run ("svn ci -m 'automatic commit' my_file.py")

    Run a command and capture exit status::

        from pexpect import *
        (command_output, exitstatus) = run ('ls -l /bin', withexitstatus=1)

    Tricky Examples
    ===============

    The following will run SSH and execute 'ls -l' on the remote machine. The
    password 'secret' will be sent if the '(?i)password' pattern is ever seen::

        run ("ssh username@machine.example.com 'ls -l'", events={'(?i)password':'secret\\n'})

    This will start mencoder to rip a video from DVD. This will also display
    progress ticks every 5 seconds as it runs. For example::

        from pexpect import *
        def print_ticks(d):
            print d['event_count'],
        run ("mencoder dvd://1 -o video.avi -oac copy -ovc copy", events={TIMEOUT:print_ticks}, timeout=5)

    The 'events' argument should be a dictionary of patterns and responses.
    Whenever one of the patterns is seen in the command out run() will send the
    associated response string. Note that you should put newlines in your
    string if Enter is necessary. The responses may also contain callback
    functions. Any callback is function that takes a dictionary as an argument.
    The dictionary contains all the locals from the run() function, so you can
    access the child spawn object or any other variable defined in run()
    (event_count, child, and extra_args are the most useful). A callback may
    return True to stop the current run process otherwise run() continues until
    the next event. A callback may also return a string which will be sent to
    the child. 'extra_args' is not used by directly run(). It provides a way to
    pass data to a callback function through run() through the locals
    dictionary passed to a callback. """

    if timeout == -1:
        child = spawn(command, maxread=2000, logfile=logfile, cwd=cwd, env=env)
    else:
        child = spawn(command, timeout=timeout, maxread=2000, logfile=logfile, cwd=cwd, env=env)
    if events is not None:
        patterns = events.keys()
        responses = events.values()
    else:
        patterns=None # We assume that EOF or TIMEOUT will save us.
        responses=None
    child_result_list = []
    event_count = 0
    while 1:
        try:
            index = child.expect (patterns)
            if type(child.after) in types.StringTypes:
                child_result_list.append(child.before + child.after)
            else: # child.after may have been a TIMEOUT or EOF, so don't cat those.
                child_result_list.append(child.before)
            if type(responses[index]) in types.StringTypes:
                child.send(responses[index])
            elif type(responses[index]) is types.FunctionType:
                callback_result = responses[index](locals())
                sys.stdout.flush()
                if type(callback_result) in types.StringTypes:
                    child.send(callback_result)
                elif callback_result:
                    break
            else:
                raise TypeError ('The callback must be a string or function type.')
            event_count = event_count + 1
        except TIMEOUT, e:
            child_result_list.append(child.before)
            break
        except EOF, e:
            child_result_list.append(child.before)
            break
    child_result = ''.join(child_result_list)
    if withexitstatus:
        child.close()
        return (child_result, child.exitstatus)
    else:
        return child_result

class spawn (object):

    """This is the main class interface for Pexpect. Use this class to start
    and control child applications. """

    def __init__(self, command, args=[], timeout=30, maxread=2000, searchwindowsize=None, logfile=None, cwd=None, env=None):

        """This is the constructor. The command parameter may be a string that
        includes a command and any arguments to the command. For example::

            child = pexpect.spawn ('/usr/bin/ftp')
            child = pexpect.spawn ('/usr/bin/ssh user@example.com')
            child = pexpect.spawn ('ls -latr /tmp')

        You may also construct it with a list of arguments like so::

            child = pexpect.spawn ('/usr/bin/ftp', [])
            child = pexpect.spawn ('/usr/bin/ssh', ['user@example.com'])
            child = pexpect.spawn ('ls', ['-latr', '/tmp'])

        After this the child application will be created and will be ready to
        talk to. For normal use, see expect() and send() and sendline().

        Remember that Pexpect does NOT interpret shell meta characters such as
        redirect, pipe, or wild cards (>, |, or *). This is a common mistake.
        If you want to run a command and pipe it through another command then
        you must also start a shell. For example::

            child = pexpect.spawn('/bin/bash -c "ls -l | grep LOG > log_list.txt"')
            child.expect(pexpect.EOF)

        The second form of spawn (where you pass a list of arguments) is useful
        in situations where you wish to spawn a command and pass it its own
        argument list. This can make syntax more clear. For example, the
        following is equivalent to the previous example::

            shell_cmd = 'ls -l | grep LOG > log_list.txt'
            child = pexpect.spawn('/bin/bash', ['-c', shell_cmd])
            child.expect(pexpect.EOF)

        The maxread attribute sets the read buffer size. This is maximum number
        of bytes that Pexpect will try to read from a TTY at one time. Setting
        the maxread size to 1 will turn off buffering. Setting the maxread
        value higher may help performance in cases where large amounts of
        output are read back from the child. This feature is useful in
        conjunction with searchwindowsize.

        The searchwindowsize attribute sets the how far back in the incomming
        seach buffer Pexpect will search for pattern matches. Every time
        Pexpect reads some data from the child it will append the data to the
        incomming buffer. The default is to search from the beginning of the
        imcomming buffer each time new data is read from the child. But this is
        very inefficient if you are running a command that generates a large
        amount of data where you want to match The searchwindowsize does not
        effect the size of the incomming data buffer. You will still have
        access to the full buffer after expect() returns.

        The logfile member turns on or off logging. All input and output will
        be copied to the given file object. Set logfile to None to stop
        logging. This is the default. Set logfile to sys.stdout to echo
        everything to standard output. The logfile is flushed after each write.

        Example log input and output to a file::

            child = pexpect.spawn('some_command')
            fout = file('mylog.txt','w')
            child.logfile = fout

        Example log to stdout::

            child = pexpect.spawn('some_command')
            child.logfile = sys.stdout

        The logfile_read and logfile_send members can be used to separately log
        the input from the child and output sent to the child. Sometimes you
        don't want to see everything you write to the child. You only want to
        log what the child sends back. For example::
        
            child = pexpect.spawn('some_command')
            child.logfile_read = sys.stdout

        To separately log output sent to the child use logfile_send::
        
            self.logfile_send = fout

        The delaybeforesend helps overcome a weird behavior that many users
        were experiencing. The typical problem was that a user would expect() a
        "Password:" prompt and then immediately call sendline() to send the
        password. The user would then see that their password was echoed back
        to them. Passwords don't normally echo. The problem is caused by the
        fact that most applications print out the "Password" prompt and then
        turn off stdin echo, but if you send your password before the
        application turned off echo, then you get your password echoed.
        Normally this wouldn't be a problem when interacting with a human at a
        real keyboard. If you introduce a slight delay just before writing then
        this seems to clear up the problem. This was such a common problem for
        many users that I decided that the default pexpect behavior should be
        to sleep just before writing to the child application. 1/20th of a
        second (50 ms) seems to be enough to clear up the problem. You can set
        delaybeforesend to 0 to return to the old behavior. Most Linux machines
        don't like this to be below 0.03. I don't know why.

        Note that spawn is clever about finding commands on your path.
        It uses the same logic that "which" uses to find executables.

        If you wish to get the exit status of the child you must call the
        close() method. The exit or signal status of the child will be stored
        in self.exitstatus or self.signalstatus. If the child exited normally
        then exitstatus will store the exit return code and signalstatus will
        be None. If the child was terminated abnormally with a signal then
        signalstatus will store the signal value and exitstatus will be None.
        If you need more detail you can also read the self.status member which
        stores the status returned by os.waitpid. You can interpret this using
        os.WIFEXITED/os.WEXITSTATUS or os.WIFSIGNALED/os.TERMSIG. """

        self.STDIN_FILENO = pty.STDIN_FILENO
        self.STDOUT_FILENO = pty.STDOUT_FILENO
        self.STDERR_FILENO = pty.STDERR_FILENO
        self.stdin = sys.stdin
        self.stdout = sys.stdout
        self.stderr = sys.stderr

        self.searcher = None
        self.ignorecase = False
        self.before = None
        self.after = None
        self.match = None
        self.match_index = None
        self.terminated = True
        self.exitstatus = None
        self.signalstatus = None
        self.status = None # status returned by os.waitpid
        self.flag_eof = False
        self.pid = None
        self.child_fd = -1 # initially closed
        self.timeout = timeout
        self.delimiter = EOF
        self.logfile = logfile
        self.logfile_read = None # input from child (read_nonblocking)
        self.logfile_send = None # output to send (send, sendline)
        self.maxread = maxread # max bytes to read at one time into buffer
        self.buffer = '' # This is the read buffer. See maxread.
        self.searchwindowsize = searchwindowsize # Anything before searchwindowsize point is preserved, but not searched.
        # Most Linux machines don't like delaybeforesend to be below 0.03 (30 ms).
        self.delaybeforesend = 0.05 # Sets sleep time used just before sending data to child. Time in seconds.
        self.delayafterclose = 0.1 # Sets delay in close() method to allow kernel time to update process status. Time in seconds.
        self.delayafterterminate = 0.1 # Sets delay in terminate() method to allow kernel time to update process status. Time in seconds.
        self.softspace = False # File-like object.
        self.name = '<' + repr(self) + '>' # File-like object.
        self.encoding = None # File-like object.
        self.closed = True # File-like object.
        self.cwd = cwd
        self.env = env
        self.__irix_hack = (sys.platform.lower().find('irix')>=0) # This flags if we are running on irix
        # Solaris uses internal __fork_pty(). All others use pty.fork().
        if (sys.platform.lower().find('solaris')>=0) or (sys.platform.lower().find('sunos5')>=0):
            self.use_native_pty_fork = False
        else:
            self.use_native_pty_fork = True


        # allow dummy instances for subclasses that may not use command or args.
        if command is None:
            self.command = None
            self.args = None
            self.name = '<pexpect factory incomplete>'
        else:
            self._spawn (command, args)

    def __del__(self):

        """This makes sure that no system resources are left open. Python only
        garbage collects Python objects. OS file descriptors are not Python
        objects, so they must be handled explicitly. If the child file
        descriptor was opened outside of this class (passed to the constructor)
        then this does not close it. """

        if not self.closed:
            # It is possible for __del__ methods to execute during the
            # teardown of the Python VM itself. Thus self.close() may
            # trigger an exception because os.close may be None.
            # -- Fernando Perez
            try:
                self.close()
            except:
                pass

    def __str__(self):

        """This returns a human-readable string that represents the state of
        the object. """

        s = []
        s.append(repr(self))
        s.append('version: ' + __version__ + ' (' + __revision__ + ')')
        s.append('command: ' + str(self.command))
        s.append('args: ' + str(self.args))
        s.append('searcher: ' + str(self.searcher))
        s.append('buffer (last 100 chars): ' + str(self.buffer)[-100:])
        s.append('before (last 100 chars): ' + str(self.before)[-100:])
        s.append('after: ' + str(self.after))
        s.append('match: ' + str(self.match))
        s.append('match_index: ' + str(self.match_index))
        s.append('exitstatus: ' + str(self.exitstatus))
        s.append('flag_eof: ' + str(self.flag_eof))
        s.append('pid: ' + str(self.pid))
        s.append('child_fd: ' + str(self.child_fd))
        s.append('closed: ' + str(self.closed))
        s.append('timeout: ' + str(self.timeout))
        s.append('delimiter: ' + str(self.delimiter))
        s.append('logfile: ' + str(self.logfile))
        s.append('logfile_read: ' + str(self.logfile_read))
        s.append('logfile_send: ' + str(self.logfile_send))
        s.append('maxread: ' + str(self.maxread))
        s.append('ignorecase: ' + str(self.ignorecase))
        s.append('searchwindowsize: ' + str(self.searchwindowsize))
        s.append('delaybeforesend: ' + str(self.delaybeforesend))
        s.append('delayafterclose: ' + str(self.delayafterclose))
        s.append('delayafterterminate: ' + str(self.delayafterterminate))
        return '\n'.join(s)

    def _spawn(self,command,args=[]):

        """This starts the given command in a child process. This does all the
        fork/exec type of stuff for a pty. This is called by __init__. If args
        is empty then command will be parsed (split on spaces) and args will be
        set to parsed arguments. """

        # The pid and child_fd of this object get set by this method.
        # Note that it is difficult for this method to fail.
        # You cannot detect if the child process cannot start.
        # So the only way you can tell if the child process started
        # or not is to try to read from the file descriptor. If you get
        # EOF immediately then it means that the child is already dead.
        # That may not necessarily be bad because you may haved spawned a child
        # that performs some task; creates no stdout output; and then dies.

        # If command is an int type then it may represent a file descriptor.
        if type(command) == type(0):
            raise ExceptionPexpect ('Command is an int type. If this is a file descriptor then maybe you want to use fdpexpect.fdspawn which takes an existing file descriptor instead of a command string.')

        if type (args) != type([]):
            raise TypeError ('The argument, args, must be a list.')

        if args == []:
            self.args = split_command_line(command)
            self.command = self.args[0]
        else:
            self.args = args[:] # work with a copy
            self.args.insert (0, command)
            self.command = command

        command_with_path = which(self.command)
        if command_with_path is None:
            raise ExceptionPexpect ('The command was not found or was not executable: %s.' % self.command)
        self.command = command_with_path
        self.args[0] = self.command

        self.name = '<' + ' '.join (self.args) + '>'

        assert self.pid is None, 'The pid member should be None.'
        assert self.command is not None, 'The command member should not be None.'

        if self.use_native_pty_fork:
            try:
                self.pid, self.child_fd = pty.fork()
            except OSError, e:
                raise ExceptionPexpect('Error! pty.fork() failed: ' + str(e))
        else: # Use internal __fork_pty
            self.pid, self.child_fd = self.__fork_pty()

        if self.pid == 0: # Child
            try:
                self.child_fd = sys.stdout.fileno() # used by setwinsize()
                self.setwinsize(24, 80)
            except:
                # Some platforms do not like setwinsize (Cygwin).
                # This will cause problem when running applications that
                # are very picky about window size.
                # This is a serious limitation, but not a show stopper.
                pass
            # Do not allow child to inherit open file descriptors from parent.
            max_fd = resource.getrlimit(resource.RLIMIT_NOFILE)[0]
            for i in range (3, max_fd):
                try:
                    os.close (i)
                except OSError:
                    pass

            # I don't know why this works, but ignoring SIGHUP fixes a
            # problem when trying to start a Java daemon with sudo
            # (specifically, Tomcat).
            signal.signal(signal.SIGHUP, signal.SIG_IGN)

            if self.cwd is not None:
                os.chdir(self.cwd)
            if self.env is None:
                os.execv(self.command, self.args)
            else:
                os.execvpe(self.command, self.args, self.env)

        # Parent
        self.terminated = False
        self.closed = False

    def __fork_pty(self):

        """This implements a substitute for the forkpty system call. This
        should be more portable than the pty.fork() function. Specifically,
        this should work on Solaris.

        Modified 10.06.05 by Geoff Marshall: Implemented __fork_pty() method to
        resolve the issue with Python's pty.fork() not supporting Solaris,
        particularly ssh. Based on patch to posixmodule.c authored by Noah
        Spurrier::

            http://mail.python.org/pipermail/python-dev/2003-May/035281.html

        """

        parent_fd, child_fd = os.openpty()
        if parent_fd < 0 or child_fd < 0:
            raise ExceptionPexpect, "Error! Could not open pty with os.openpty()."

        pid = os.fork()
        if pid < 0:
            raise ExceptionPexpect, "Error! Failed os.fork()."
        elif pid == 0:
            # Child.
            os.close(parent_fd)
            self.__pty_make_controlling_tty(child_fd)

            os.dup2(child_fd, 0)
            os.dup2(child_fd, 1)
            os.dup2(child_fd, 2)

            if child_fd > 2:
                os.close(child_fd)
        else:
            # Parent.
            os.close(child_fd)

        return pid, parent_fd

    def __pty_make_controlling_tty(self, tty_fd):

        """This makes the pseudo-terminal the controlling tty. This should be
        more portable than the pty.fork() function. Specifically, this should
        work on Solaris. """

        child_name = os.ttyname(tty_fd)

        # Disconnect from controlling tty if still connected.
        try:
            fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY);
            if fd >= 0:
                os.close(fd)
        except:
            # We are already disconnected. Perhaps we are running inside cron.
            pass

        os.setsid()

        # Verify we are disconnected from controlling tty
        try:
            fd = os.open("/dev/tty", os.O_RDWR | os.O_NOCTTY);
            if fd >= 0:
                os.close(fd)
                raise ExceptionPexpect, "Error! We are not disconnected from a controlling tty."
        except:
            # Good! We are disconnected from a controlling tty.
            pass

        # Verify we can open child pty.
        fd = os.open(child_name, os.O_RDWR);
        if fd < 0:
            raise ExceptionPexpect, "Error! Could not open child pty, " + child_name
        else:
            os.close(fd)

        # Verify we now have a controlling tty.
        fd = os.open("/dev/tty", os.O_WRONLY)
        if fd < 0:
            raise ExceptionPexpect, "Error! Could not open controlling tty, /dev/tty"
        else:
            os.close(fd)

    def fileno (self):   # File-like object.

        """This returns the file descriptor of the pty for the child.
        """

        return self.child_fd

    def close (self, force=True):   # File-like object.

        """This closes the connection with the child application. Note that
        calling close() more than once is valid. This emulates standard Python
        behavior with files. Set force to True if you want to make sure that
        the child is terminated (SIGKILL is sent if the child ignores SIGHUP
        and SIGINT). """

        if not self.closed:
            self.flush()
            os.close (self.child_fd)
            time.sleep(self.delayafterclose) # Give kernel time to update process status.
            if self.isalive():
                if not self.terminate(force):
                    raise ExceptionPexpect ('close() could not terminate the child using terminate()')
            self.child_fd = -1
            self.closed = True
            #self.pid = None

    def flush (self):   # File-like object.

        """This does nothing. It is here to support the interface for a
        File-like object. """

        pass

    def isatty (self):   # File-like object.

        """This returns True if the file descriptor is open and connected to a
        tty(-like) device, else False. """

        return os.isatty(self.child_fd)

    def waitnoecho (self, timeout=-1):

        """This waits until the terminal ECHO flag is set False. This returns
        True if the echo mode is off. This returns False if the ECHO flag was
        not set False before the timeout. This can be used to detect when the
        child is waiting for a password. Usually a child application will turn
        off echo mode when it is waiting for the user to enter a password. For
        example, instead of expecting the "password:" prompt you can wait for
        the child to set ECHO off::

            p = pexpect.spawn ('ssh user@example.com')
            p.waitnoecho()
            p.sendline(mypassword)

        If timeout is None then this method to block forever until ECHO flag is
        False.

        """

        if timeout == -1:
            timeout = self.timeout
        if timeout is not None:
            end_time = time.time() + timeout 
        while True:
            if not self.getecho():
                return True
            if timeout < 0 and timeout is not None:
                return False
            if timeout is not None:
                timeout = end_time - time.time()
            time.sleep(0.1)

    def getecho (self):

        """This returns the terminal echo mode. This returns True if echo is
        on or False if echo is off. Child applications that are expecting you
        to enter a password often set ECHO False. See waitnoecho(). """

        attr = termios.tcgetattr(self.child_fd)
        if attr[3] & termios.ECHO:
            return True
        return False

    def setecho (self, state):

        """This sets the terminal echo mode on or off. Note that anything the
        child sent before the echo will be lost, so you should be sure that
        your input buffer is empty before you call setecho(). For example, the
        following will work as expected::

            p = pexpect.spawn('cat')
            p.sendline ('1234') # We will see this twice (once from tty echo and again from cat).
            p.expect (['1234'])
            p.expect (['1234'])
            p.setecho(False) # Turn off tty echo
            p.sendline ('abcd') # We will set this only once (echoed by cat).
            p.sendline ('wxyz') # We will set this only once (echoed by cat)
            p.expect (['abcd'])
            p.expect (['wxyz'])

        The following WILL NOT WORK because the lines sent before the setecho
        will be lost::

            p = pexpect.spawn('cat')
            p.sendline ('1234') # We will see this twice (once from tty echo and again from cat).
            p.setecho(False) # Turn off tty echo
            p.sendline ('abcd') # We will set this only once (echoed by cat).
            p.sendline ('wxyz') # We will set this only once (echoed by cat)
            p.expect (['1234'])
            p.expect (['1234'])
            p.expect (['abcd'])
            p.expect (['wxyz'])
        """

        self.child_fd
        attr = termios.tcgetattr(self.child_fd)
        if state:
            attr[3] = attr[3] | termios.ECHO
        else:
            attr[3] = attr[3] & ~termios.ECHO
        # I tried TCSADRAIN and TCSAFLUSH, but these were inconsistent
        # and blocked on some platforms. TCSADRAIN is probably ideal if it worked.
        termios.tcsetattr(self.child_fd, termios.TCSANOW, attr)

    def read_nonblocking (self, size = 1, timeout = -1):

        """This reads at most size characters from the child application. It
        includes a timeout. If the read does not complete within the timeout
        period then a TIMEOUT exception is raised. If the end of file is read
        then an EOF exception will be raised. If a log file was set using
        setlog() then all data will also be written to the log file.

        If timeout is None then the read may block indefinitely. If timeout is -1
        then the self.timeout value is used. If timeout is 0 then the child is
        polled and if there was no data immediately ready then this will raise
        a TIMEOUT exception.

        The timeout refers only to the amount of time to read at least one
        character. This is not effected by the 'size' parameter, so if you call
        read_nonblocking(size=100, timeout=30) and only one character is
        available right away then one character will be returned immediately.
        It will not wait for 30 seconds for another 99 characters to come in.

        This is a wrapper around os.read(). It uses select.select() to
        implement the timeout. """

        if self.closed:
            raise ValueError ('I/O operation on closed file in read_nonblocking().')

        if timeout == -1:
            timeout = self.timeout

        # Note that some systems such as Solaris do not give an EOF when
        # the child dies. In fact, you can still try to read
        # from the child_fd -- it will block forever or until TIMEOUT.
        # For this case, I test isalive() before doing any reading.
        # If isalive() is false, then I pretend that this is the same as EOF.
        if not self.isalive():
            r,w,e = self.__select([self.child_fd], [], [], 0) # timeout of 0 means "poll"
            if not r:
                self.flag_eof = True
                raise EOF ('End Of File (EOF) in read_nonblocking(). Braindead platform.')
        elif self.__irix_hack:
            # This is a hack for Irix. It seems that Irix requires a long delay before checking isalive.
            # This adds a 2 second delay, but only when the child is terminated.
            r, w, e = self.__select([self.child_fd], [], [], 2)
            if not r and not self.isalive():
                self.flag_eof = True
                raise EOF ('End Of File (EOF) in read_nonblocking(). Pokey platform.')

        r,w,e = self.__select([self.child_fd], [], [], timeout)

        if not r:
            if not self.isalive():
                # Some platforms, such as Irix, will claim that their processes are alive;
                # then timeout on the select; and then finally admit that they are not alive.
                self.flag_eof = True
                raise EOF ('End of File (EOF) in read_nonblocking(). Very pokey platform.')
            else:
                raise TIMEOUT ('Timeout exceeded in read_nonblocking().')

        if self.child_fd in r:
            try:
                s = os.read(self.child_fd, size)
            except OSError, e: # Linux does this
                self.flag_eof = True
                raise EOF ('End Of File (EOF) in read_nonblocking(). Exception style platform.')
            if s == '': # BSD style
                self.flag_eof = True
                raise EOF ('End Of File (EOF) in read_nonblocking(). Empty string style platform.')

            if self.logfile is not None:
                self.logfile.write (s)
                self.logfile.flush()
            if self.logfile_read is not None:
                self.logfile_read.write (s)
                self.logfile_read.flush()

            return s

        raise ExceptionPexpect ('Reached an unexpected state in read_nonblocking().')

    def read (self, size = -1):   # File-like object.

        """This reads at most "size" bytes from the file (less if the read hits
        EOF before obtaining size bytes). If the size argument is negative or
        omitted, read all data until EOF is reached. The bytes are returned as
        a string object. An empty string is returned when EOF is encountered
        immediately. """

        if size == 0:
            return ''
        if size < 0:
            self.expect (self.delimiter) # delimiter default is EOF
            return self.before

        # I could have done this more directly by not using expect(), but
        # I deliberately decided to couple read() to expect() so that
        # I would catch any bugs early and ensure consistant behavior.
        # It's a little less efficient, but there is less for me to
        # worry about if I have to later modify read() or expect().
        # Note, it's OK if size==-1 in the regex. That just means it
        # will never match anything in which case we stop only on EOF.
        cre = re.compile('.{%d}' % size, re.DOTALL)
        index = self.expect ([cre, self.delimiter]) # delimiter default is EOF
        if index == 0:
            return self.after ### self.before should be ''. Should I assert this?
        return self.before

    def readline (self, size = -1):    # File-like object.

        """This reads and returns one entire line. A trailing newline is kept
        in the string, but may be absent when a file ends with an incomplete
        line. Note: This readline() looks for a \\r\\n pair even on UNIX
        because this is what the pseudo tty device returns. So contrary to what
        you may expect you will receive the newline as \\r\\n. An empty string
        is returned when EOF is hit immediately. Currently, the size argument is
        mostly ignored, so this behavior is not standard for a file-like
        object. If size is 0 then an empty string is returned. """

        if size == 0:
            return ''
        index = self.expect (['\r\n', self.delimiter]) # delimiter default is EOF
        if index == 0:
            return self.before + '\r\n'
        else:
            return self.before

    def __iter__ (self):    # File-like object.

        """This is to support iterators over a file-like object.
        """

        return self

    def next (self):    # File-like object.

        """This is to support iterators over a file-like object.
        """

        result = self.readline()
        if result == "":
            raise StopIteration
        return result

    def readlines (self, sizehint = -1):    # File-like object.

        """This reads until EOF using readline() and returns a list containing
        the lines thus read. The optional "sizehint" argument is ignored. """

        lines = []
        while True:
            line = self.readline()
            if not line:
                break
            lines.append(line)
        return lines

    def write(self, s):   # File-like object.

        """This is similar to send() except that there is no return value.
        """

        self.send (s)

    def writelines (self, sequence):   # File-like object.

        """This calls write() for each element in the sequence. The sequence
        can be any iterable object producing strings, typically a list of
        strings. This does not add line separators There is no return value.
        """

        for s in sequence:
            self.write (s)

    def send(self, s):

        """This sends a string to the child process. This returns the number of
        bytes written. If a log file was set then the data is also written to
        the log. """

        time.sleep(self.delaybeforesend)
        if self.logfile is not None:
            self.logfile.write (s)
            self.logfile.flush()
        if self.logfile_send is not None:
            self.logfile_send.write (s)
            self.logfile_send.flush()
        c = os.write(self.child_fd, s)
        return c

    def sendline(self, s=''):

        """This is like send(), but it adds a line feed (os.linesep). This
        returns the number of bytes written. """

        n = self.send(s)
        n = n + self.send (os.linesep)
        return n

    def sendcontrol(self, char):

        """This sends a control character to the child such as Ctrl-C or
        Ctrl-D. For example, to send a Ctrl-G (ASCII 7)::

            child.sendcontrol('g')

        See also, sendintr() and sendeof().
        """

        char = char.lower()
        a = ord(char)
        if a>=97 and a<=122:
            a = a - ord('a') + 1
            return self.send (chr(a))
        d = {'@':0, '`':0,
            '[':27, '{':27,
            '\\':28, '|':28,
            ']':29, '}': 29,
            '^':30, '~':30,
            '_':31,
            '?':127}
        if char not in d:
            return 0
        return self.send (chr(d[char]))

    def sendeof(self):

        """This sends an EOF to the child. This sends a character which causes
        the pending parent output buffer to be sent to the waiting child
        program without waiting for end-of-line. If it is the first character
        of the line, the read() in the user program returns 0, which signifies
        end-of-file. This means to work as expected a sendeof() has to be
        called at the beginning of a line. This method does not send a newline.
        It is the responsibility of the caller to ensure the eof is sent at the
        beginning of a line. """

        ### Hmmm... how do I send an EOF?
        ###C  if ((m = write(pty, *buf, p - *buf)) < 0)
        ###C      return (errno == EWOULDBLOCK) ? n : -1;
        #fd = sys.stdin.fileno()
        #old = termios.tcgetattr(fd) # remember current state
        #attr = termios.tcgetattr(fd)
        #attr[3] = attr[3] | termios.ICANON # ICANON must be set to recognize EOF
        #try: # use try/finally to ensure state gets restored
        #    termios.tcsetattr(fd, termios.TCSADRAIN, attr)
        #    if hasattr(termios, 'CEOF'):
        #        os.write (self.child_fd, '%c' % termios.CEOF)
        #    else:
        #        # Silly platform does not define CEOF so assume CTRL-D
        #        os.write (self.child_fd, '%c' % 4)
        #finally: # restore state
        #    termios.tcsetattr(fd, termios.TCSADRAIN, old)
        if hasattr(termios, 'VEOF'):
            char = termios.tcgetattr(self.child_fd)[6][termios.VEOF]
        else:
            # platform does not define VEOF so assume CTRL-D
            char = chr(4)
        self.send(char)

    def sendintr(self):

        """This sends a SIGINT to the child. It does not require
        the SIGINT to be the first character on a line. """

        if hasattr(termios, 'VINTR'):
            char = termios.tcgetattr(self.child_fd)[6][termios.VINTR]
        else:
            # platform does not define VINTR so assume CTRL-C
            char = chr(3)
        self.send (char)

    def eof (self):

        """This returns True if the EOF exception was ever raised.
        """

        return self.flag_eof

    def terminate(self, force=False):

        """This forces a child process to terminate. It starts nicely with
        SIGHUP and SIGINT. If "force" is True then moves onto SIGKILL. This
        returns True if the child was terminated. This returns False if the
        child could not be terminated. """

        if not self.isalive():
            return True
        try:
            self.kill(signal.SIGHUP)
            time.sleep(self.delayafterterminate)
            if not self.isalive():
                return True
            self.kill(signal.SIGCONT)
            time.sleep(self.delayafterterminate)
            if not self.isalive():
                return True
            self.kill(signal.SIGINT)
            time.sleep(self.delayafterterminate)
            if not self.isalive():
                return True
            if force:
                self.kill(signal.SIGKILL)
                time.sleep(self.delayafterterminate)
                if not self.isalive():
                    return True
                else:
                    return False
            return False
        except OSError, e:
            # I think there are kernel timing issues that sometimes cause
            # this to happen. I think isalive() reports True, but the
            # process is dead to the kernel.
            # Make one last attempt to see if the kernel is up to date.
            time.sleep(self.delayafterterminate)
            if not self.isalive():
                return True
            else:
                return False

    def wait(self):

        """This waits until the child exits. This is a blocking call. This will
        not read any data from the child, so this will block forever if the
        child has unread output and has terminated. In other words, the child
        may have printed output then called exit(); but, technically, the child
        is still alive until its output is read. """

        if self.isalive():
            pid, status = os.waitpid(self.pid, 0)
        else:
            raise ExceptionPexpect ('Cannot wait for dead child process.')
        self.exitstatus = os.WEXITSTATUS(status)
        if os.WIFEXITED (status):
            self.status = status
            self.exitstatus = os.WEXITSTATUS(status)
            self.signalstatus = None
            self.terminated = True
        elif os.WIFSIGNALED (status):
            self.status = status
            self.exitstatus = None
            self.signalstatus = os.WTERMSIG(status)
            self.terminated = True
        elif os.WIFSTOPPED (status):
            raise ExceptionPexpect ('Wait was called for a child process that is stopped. This is not supported. Is some other process attempting job control with our child pid?')
        return self.exitstatus

    def isalive(self):

        """This tests if the child process is running or not. This is
        non-blocking. If the child was terminated then this will read the
        exitstatus or signalstatus of the child. This returns True if the child
        process appears to be running or False if not. It can take literally
        SECONDS for Solaris to return the right status. """

        if self.terminated:
            return False

        if self.flag_eof:
            # This is for Linux, which requires the blocking form of waitpid to get
            # status of a defunct process. This is super-lame. The flag_eof would have
            # been set in read_nonblocking(), so this should be safe.
            waitpid_options = 0
        else:
            waitpid_options = os.WNOHANG

        try:
            pid, status = os.waitpid(self.pid, waitpid_options)
        except OSError, e: # No child processes
            if e[0] == errno.ECHILD:
                raise ExceptionPexpect ('isalive() encountered condition where "terminated" is 0, but there was no child process. Did someone else call waitpid() on our process?')
            else:
                raise e

        # I have to do this twice for Solaris. I can't even believe that I figured this out...
        # If waitpid() returns 0 it means that no child process wishes to
        # report, and the value of status is undefined.
        if pid == 0:
            try:
                pid, status = os.waitpid(self.pid, waitpid_options) ### os.WNOHANG) # Solaris!
            except OSError, e: # This should never happen...
                if e[0] == errno.ECHILD:
                    raise ExceptionPexpect ('isalive() encountered condition that should never happen. There was no child process. Did someone else call waitpid() on our process?')
                else:
                    raise e

            # If pid is still 0 after two calls to waitpid() then
            # the process really is alive. This seems to work on all platforms, except
            # for Irix which seems to require a blocking call on waitpid or select, so I let read_nonblocking
            # take care of this situation (unfortunately, this requires waiting through the timeout).
            if pid == 0:
                return True

        if pid == 0:
            return True

        if os.WIFEXITED (status):
            self.status = status
            self.exitstatus = os.WEXITSTATUS(status)
            self.signalstatus = None
            self.terminated = True
        elif os.WIFSIGNALED (status):
            self.status = status
            self.exitstatus = None
            self.signalstatus = os.WTERMSIG(status)
            self.terminated = True
        elif os.WIFSTOPPED (status):
            raise ExceptionPexpect ('isalive() encountered condition where child process is stopped. This is not supported. Is some other process attempting job control with our child pid?')
        return False

    def kill(self, sig):

        """This sends the given signal to the child application. In keeping
        with UNIX tradition it has a misleading name. It does not necessarily
        kill the child unless you send the right signal. """

        # Same as os.kill, but the pid is given for you.
        if self.isalive():
            os.kill(self.pid, sig)

    def compile_pattern_list(self, patterns):

        """This compiles a pattern-string or a list of pattern-strings.
        Patterns must be a StringType, EOF, TIMEOUT, SRE_Pattern, or a list of
        those. Patterns may also be None which results in an empty list (you
        might do this if waiting for an EOF or TIMEOUT condition without
        expecting any pattern).

        This is used by expect() when calling expect_list(). Thus expect() is
        nothing more than::

             cpl = self.compile_pattern_list(pl)
             return self.expect_list(cpl, timeout)

        If you are using expect() within a loop it may be more
        efficient to compile the patterns first and then call expect_list().
        This avoid calls in a loop to compile_pattern_list()::

             cpl = self.compile_pattern_list(my_pattern)
             while some_condition:
                ...
                i = self.expect_list(clp, timeout)
                ...
        """

        if patterns is None:
            return []
        if type(patterns) is not types.ListType:
            patterns = [patterns]

        compile_flags = re.DOTALL # Allow dot to match \n
        if self.ignorecase:
            compile_flags = compile_flags | re.IGNORECASE
        compiled_pattern_list = []
        for p in patterns:
            if type(p) in types.StringTypes:
                compiled_pattern_list.append(re.compile(p, compile_flags))
            elif p is EOF:
                compiled_pattern_list.append(EOF)
            elif p is TIMEOUT:
                compiled_pattern_list.append(TIMEOUT)
            elif type(p) is type(re.compile('')):
                compiled_pattern_list.append(p)
            else:
                raise TypeError ('Argument must be one of StringTypes, EOF, TIMEOUT, SRE_Pattern, or a list of those type. %s' % str(type(p)))

        return compiled_pattern_list

    def expect(self, pattern, timeout = -1, searchwindowsize=-1):

        """This seeks through the stream until a pattern is matched. The
        pattern is overloaded and may take several types. The pattern can be a
        StringType, EOF, a compiled re, or a list of any of those types.
        Strings will be compiled to re types. This returns the index into the
        pattern list. If the pattern was not a list this returns index 0 on a
        successful match. This may raise exceptions for EOF or TIMEOUT. To
        avoid the EOF or TIMEOUT exceptions add EOF or TIMEOUT to the pattern
        list. That will cause expect to match an EOF or TIMEOUT condition
        instead of raising an exception.

        If you pass a list of patterns and more than one matches, the first match
        in the stream is chosen. If more than one pattern matches at that point,
        the leftmost in the pattern list is chosen. For example::

            # the input is 'foobar'
            index = p.expect (['bar', 'foo', 'foobar'])
            # returns 1 ('foo') even though 'foobar' is a "better" match

        Please note, however, that buffering can affect this behavior, since
        input arrives in unpredictable chunks. For example::

            # the input is 'foobar'
            index = p.expect (['foobar', 'foo'])
            # returns 0 ('foobar') if all input is available at once,
            # but returs 1 ('foo') if parts of the final 'bar' arrive late

        After a match is found the instance attributes 'before', 'after' and
        'match' will be set. You can see all the data read before the match in
        'before'. You can see the data that was matched in 'after'. The
        re.MatchObject used in the re match will be in 'match'. If an error
        occurred then 'before' will be set to all the data read so far and
        'after' and 'match' will be None.

        If timeout is -1 then timeout will be set to the self.timeout value.

        A list entry may be EOF or TIMEOUT instead of a string. This will
        catch these exceptions and return the index of the list entry instead
        of raising the exception. The attribute 'after' will be set to the
        exception type. The attribute 'match' will be None. This allows you to
        write code like this::

                index = p.expect (['good', 'bad', pexpect.EOF, pexpect.TIMEOUT])
                if index == 0:
                    do_something()
                elif index == 1:
                    do_something_else()
                elif index == 2:
                    do_some_other_thing()
                elif index == 3:
                    do_something_completely_different()

        instead of code like this::

                try:
                    index = p.expect (['good', 'bad'])
                    if index == 0:
                        do_something()
                    elif index == 1:
                        do_something_else()
                except EOF:
                    do_some_other_thing()
                except TIMEOUT:
                    do_something_completely_different()

        These two forms are equivalent. It all depends on what you want. You
        can also just expect the EOF if you are waiting for all output of a
        child to finish. For example::

                p = pexpect.spawn('/bin/ls')
                p.expect (pexpect.EOF)
                print p.before

        If you are trying to optimize for speed then see expect_list().
        """

        compiled_pattern_list = self.compile_pattern_list(pattern)
        return self.expect_list(compiled_pattern_list, timeout, searchwindowsize)

    def expect_list(self, pattern_list, timeout = -1, searchwindowsize = -1):

        """This takes a list of compiled regular expressions and returns the
        index into the pattern_list that matched the child output. The list may
        also contain EOF or TIMEOUT (which are not compiled regular
        expressions). This method is similar to the expect() method except that
        expect_list() does not recompile the pattern list on every call. This
        may help if you are trying to optimize for speed, otherwise just use
        the expect() method.  This is called by expect(). If timeout==-1 then
        the self.timeout value is used. If searchwindowsize==-1 then the
        self.searchwindowsize value is used. """

        return self.expect_loop(searcher_re(pattern_list), timeout, searchwindowsize)

    def expect_exact(self, pattern_list, timeout = -1, searchwindowsize = -1):

        """This is similar to expect(), but uses plain string matching instead
        of compiled regular expressions in 'pattern_list'. The 'pattern_list'
        may be a string; a list or other sequence of strings; or TIMEOUT and
        EOF.

        This call might be faster than expect() for two reasons: string
        searching is faster than RE matching and it is possible to limit the
        search to just the end of the input buffer.

        This method is also useful when you don't want to have to worry about
        escaping regular expression characters that you want to match."""

        if type(pattern_list) in types.StringTypes or pattern_list in (TIMEOUT, EOF):
            pattern_list = [pattern_list]
        return self.expect_loop(searcher_string(pattern_list), timeout, searchwindowsize)

    def expect_loop(self, searcher, timeout = -1, searchwindowsize = -1):

        """This is the common loop used inside expect. The 'searcher' should be
        an instance of searcher_re or searcher_string, which describes how and what
        to search for in the input.

        See expect() for other arguments, return value and exceptions. """

        self.searcher = searcher

        if timeout == -1:
            timeout = self.timeout
        if timeout is not None:
            end_time = time.time() + timeout 
        if searchwindowsize == -1:
            searchwindowsize = self.searchwindowsize

        try:
            incoming = self.buffer
            freshlen = len(incoming)
            while True: # Keep reading until exception or return.
                index = searcher.search(incoming, freshlen, searchwindowsize)
                if index >= 0:
                    self.buffer = incoming[searcher.end : ]
                    self.before = incoming[ : searcher.start]
                    self.after = incoming[searcher.start : searcher.end]
                    self.match = searcher.match
                    self.match_index = index
                    return self.match_index
                # No match at this point
                if timeout < 0 and timeout is not None:
                    raise TIMEOUT ('Timeout exceeded in expect_any().')
                # Still have time left, so read more data
                c = self.read_nonblocking (self.maxread, timeout)
                freshlen = len(c)
                time.sleep (0.0001)
                incoming = incoming + c
                if timeout is not None:
                    timeout = end_time - time.time()
        except EOF, e:
            self.buffer = ''
            self.before = incoming
            self.after = EOF
            index = searcher.eof_index
            if index >= 0:
                self.match = EOF
                self.match_index = index
                return self.match_index
            else:
                self.match = None
                self.match_index = None
                raise EOF (str(e) + '\n' + str(self))
        except TIMEOUT, e:
            self.buffer = incoming
            self.before = incoming
            self.after = TIMEOUT
            index = searcher.timeout_index
            if index >= 0:
                self.match = TIMEOUT
                self.match_index = index
                return self.match_index
            else:
                self.match = None
                self.match_index = None
                raise TIMEOUT (str(e) + '\n' + str(self))
        except:
            self.before = incoming
            self.after = None
            self.match = None
            self.match_index = None
            raise

    def getwinsize(self):

        """This returns the terminal window size of the child tty. The return
        value is a tuple of (rows, cols). """

        TIOCGWINSZ = getattr(termios, 'TIOCGWINSZ', 1074295912L)
        s = struct.pack('HHHH', 0, 0, 0, 0)
        x = fcntl.ioctl(self.fileno(), TIOCGWINSZ, s)
        return struct.unpack('HHHH', x)[0:2]

    def setwinsize(self, r, c):

        """This sets the terminal window size of the child tty. This will cause
        a SIGWINCH signal to be sent to the child. This does not change the
        physical window size. It changes the size reported to TTY-aware
        applications like vi or curses -- applications that respond to the
        SIGWINCH signal. """

        # Check for buggy platforms. Some Python versions on some platforms
        # (notably OSF1 Alpha and RedHat 7.1) truncate the value for
        # termios.TIOCSWINSZ. It is not clear why this happens.
        # These platforms don't seem to handle the signed int very well;
        # yet other platforms like OpenBSD have a large negative value for
        # TIOCSWINSZ and they don't have a truncate problem.
        # Newer versions of Linux have totally different values for TIOCSWINSZ.
        # Note that this fix is a hack.
        TIOCSWINSZ = getattr(termios, 'TIOCSWINSZ', -2146929561)
        if TIOCSWINSZ == 2148037735L: # L is not required in Python >= 2.2.
            TIOCSWINSZ = -2146929561 # Same bits, but with sign.
        # Note, assume ws_xpixel and ws_ypixel are zero.
        s = struct.pack('HHHH', r, c, 0, 0)
        fcntl.ioctl(self.fileno(), TIOCSWINSZ, s)

    def interact(self, escape_character = chr(29), input_filter = None, output_filter = None):

        """This gives control of the child process to the interactive user (the
        human at the keyboard). Keystrokes are sent to the child process, and
        the stdout and stderr output of the child process is printed. This
        simply echos the child stdout and child stderr to the real stdout and
        it echos the real stdin to the child stdin. When the user types the
        escape_character this method will stop. The default for
        escape_character is ^]. This should not be confused with ASCII 27 --
        the ESC character. ASCII 29 was chosen for historical merit because
        this is the character used by 'telnet' as the escape character. The
        escape_character will not be sent to the child process.

        You may pass in optional input and output filter functions. These
        functions should take a string and return a string. The output_filter
        will be passed all the output from the child process. The input_filter
        will be passed all the keyboard input from the user. The input_filter
        is run BEFORE the check for the escape_character.

        Note that if you change the window size of the parent the SIGWINCH
        signal will not be passed through to the child. If you want the child
        window size to change when the parent's window size changes then do
        something like the following example::

            import pexpect, struct, fcntl, termios, signal, sys
            def sigwinch_passthrough (sig, data):
                s = struct.pack("HHHH", 0, 0, 0, 0)
                a = struct.unpack('hhhh', fcntl.ioctl(sys.stdout.fileno(), termios.TIOCGWINSZ , s))
                global p
                p.setwinsize(a[0],a[1])
            p = pexpect.spawn('/bin/bash') # Note this is global and used in sigwinch_passthrough.
            signal.signal(signal.SIGWINCH, sigwinch_passthrough)
            p.interact()
        """

        # Flush the buffer.
        self.stdout.write (self.buffer)
        self.stdout.flush()
        self.buffer = ''
        mode = tty.tcgetattr(self.STDIN_FILENO)
        tty.setraw(self.STDIN_FILENO)
        try:
            self.__interact_copy(escape_character, input_filter, output_filter)
        finally:
            tty.tcsetattr(self.STDIN_FILENO, tty.TCSAFLUSH, mode)

    def __interact_writen(self, fd, data):

        """This is used by the interact() method.
        """

        while data != '' and self.isalive():
            n = os.write(fd, data)
            data = data[n:]

    def __interact_read(self, fd):

        """This is used by the interact() method.
        """

        return os.read(fd, 1000)

    def __interact_copy(self, escape_character = None, input_filter = None, output_filter = None):

        """This is used by the interact() method.
        """

        while self.isalive():
            r,w,e = self.__select([self.child_fd, self.STDIN_FILENO], [], [])
            if self.child_fd in r:
                data = self.__interact_read(self.child_fd)
                if output_filter: data = output_filter(data)
                if self.logfile is not None:
                    self.logfile.write (data)
                    self.logfile.flush()
                os.write(self.STDOUT_FILENO, data)
            if self.STDIN_FILENO in r:
                data = self.__interact_read(self.STDIN_FILENO)
                if input_filter: data = input_filter(data)
                i = data.rfind(escape_character)
                if i != -1:
                    data = data[:i]
                    self.__interact_writen(self.child_fd, data)
                    break
                self.__interact_writen(self.child_fd, data)

    def __select (self, iwtd, owtd, ewtd, timeout=None):

        """This is a wrapper around select.select() that ignores signals. If
        select.select raises a select.error exception and errno is an EINTR
        error then it is ignored. Mainly this is used to ignore sigwinch
        (terminal resize). """

        # if select() is interrupted by a signal (errno==EINTR) then
        # we loop back and enter the select() again.
        if timeout is not None:
            end_time = time.time() + timeout
        while True:
            try:
                return select.select (iwtd, owtd, ewtd, timeout)
            except select.error, e:
                if e[0] == errno.EINTR:
                    # if we loop back we have to subtract the amount of time we already waited.
                    if timeout is not None:
                        timeout = end_time - time.time()
                        if timeout < 0:
                            return ([],[],[])
                else: # something else caused the select.error, so this really is an exception
                    raise

##############################################################################
# The following methods are no longer supported or allowed.

    def setmaxread (self, maxread):

        """This method is no longer supported or allowed. I don't like getters
        and setters without a good reason. """

        raise ExceptionPexpect ('This method is no longer supported or allowed. Just assign a value to the maxread member variable.')

    def setlog (self, fileobject):

        """This method is no longer supported or allowed.
        """

        raise ExceptionPexpect ('This method is no longer supported or allowed. Just assign a value to the logfile member variable.')

##############################################################################
# End of spawn class
##############################################################################

class searcher_string (object):

    """This is a plain string search helper for the spawn.expect_any() method.

    Attributes:

        eof_index     - index of EOF, or -1
        timeout_index - index of TIMEOUT, or -1

    After a successful match by the search() method the following attributes
    are available:

        start - index into the buffer, first byte of match
        end   - index into the buffer, first byte after match
        match - the matching string itself
    """

    def __init__(self, strings):

        """This creates an instance of searcher_string. This argument 'strings'
        may be a list; a sequence of strings; or the EOF or TIMEOUT types. """

        self.eof_index = -1
        self.timeout_index = -1
        self._strings = []
        for n, s in zip(range(len(strings)), strings):
            if s is EOF:
                self.eof_index = n
                continue
            if s is TIMEOUT:
                self.timeout_index = n
                continue
            self._strings.append((n, s))

    def __str__(self):

        """This returns a human-readable string that represents the state of
        the object."""

        ss =  [ (ns[0],'    %d: "%s"' % ns) for ns in self._strings ]
        ss.append((-1,'searcher_string:'))
        if self.eof_index >= 0:
            ss.append ((self.eof_index,'    %d: EOF' % self.eof_index))
        if self.timeout_index >= 0:
            ss.append ((self.timeout_index,'    %d: TIMEOUT' % self.timeout_index))
        ss.sort()
        ss = zip(*ss)[1]
        return '\n'.join(ss)

    def search(self, buffer, freshlen, searchwindowsize=None):

        """This searches 'buffer' for the first occurence of one of the search
        strings.  'freshlen' must indicate the number of bytes at the end of
        'buffer' which have not been searched before. It helps to avoid
        searching the same, possibly big, buffer over and over again.

        See class spawn for the 'searchwindowsize' argument.

        If there is a match this returns the index of that string, and sets
        'start', 'end' and 'match'. Otherwise, this returns -1. """

        absurd_match = len(buffer)
        first_match = absurd_match

        # 'freshlen' helps a lot here. Further optimizations could
        # possibly include:
        #
        # using something like the Boyer-Moore Fast String Searching
        # Algorithm; pre-compiling the search through a list of
        # strings into something that can scan the input once to
        # search for all N strings; realize that if we search for
        # ['bar', 'baz'] and the input is '...foo' we need not bother
        # rescanning until we've read three more bytes.
        #
        # Sadly, I don't know enough about this interesting topic. /grahn
        
        for index, s in self._strings:
            if searchwindowsize is None:
                # the match, if any, can only be in the fresh data,
                # or at the very end of the old data
                offset = -(freshlen+len(s))
            else:
                # better obey searchwindowsize
                offset = -searchwindowsize
            n = buffer.find(s, offset)
            if n >= 0 and n < first_match:
                first_match = n
                best_index, best_match = index, s
        if first_match == absurd_match:
            return -1
        self.match = best_match
        self.start = first_match
        self.end = self.start + len(self.match)
        return best_index

class searcher_re (object):

    """This is regular expression string search helper for the
    spawn.expect_any() method.

    Attributes:

        eof_index     - index of EOF, or -1
        timeout_index - index of TIMEOUT, or -1

    After a successful match by the search() method the following attributes
    are available:

        start - index into the buffer, first byte of match
        end   - index into the buffer, first byte after match
        match - the re.match object returned by a succesful re.search

    """

    def __init__(self, patterns):

        """This creates an instance that searches for 'patterns' Where
        'patterns' may be a list or other sequence of compiled regular
        expressions, or the EOF or TIMEOUT types."""

        self.eof_index = -1
        self.timeout_index = -1
        self._searches = []
        for n, s in zip(range(len(patterns)), patterns):
            if s is EOF:
                self.eof_index = n
                continue
            if s is TIMEOUT:
                self.timeout_index = n
                continue
            self._searches.append((n, s))

    def __str__(self):

        """This returns a human-readable string that represents the state of
        the object."""

        ss =  [ (n,'    %d: re.compile("%s")' % (n,str(s.pattern))) for n,s in self._searches]
        ss.append((-1,'searcher_re:'))
        if self.eof_index >= 0:
            ss.append ((self.eof_index,'    %d: EOF' % self.eof_index))
        if self.timeout_index >= 0:
            ss.append ((self.timeout_index,'    %d: TIMEOUT' % self.timeout_index))
        ss.sort()
        ss = zip(*ss)[1]
        return '\n'.join(ss)

    def search(self, buffer, freshlen, searchwindowsize=None):

        """This searches 'buffer' for the first occurence of one of the regular
        expressions. 'freshlen' must indicate the number of bytes at the end of
        'buffer' which have not been searched before.

        See class spawn for the 'searchwindowsize' argument.
        
        If there is a match this returns the index of that string, and sets
        'start', 'end' and 'match'. Otherwise, returns -1."""

        absurd_match = len(buffer)
        first_match = absurd_match
        # 'freshlen' doesn't help here -- we cannot predict the
        # length of a match, and the re module provides no help.
        if searchwindowsize is None:
            searchstart = 0
        else:
            searchstart = max(0, len(buffer)-searchwindowsize)
        for index, s in self._searches:
            match = s.search(buffer, searchstart)
            if match is None:
                continue
            n = match.start()
            if n < first_match:
                first_match = n
                the_match = match
                best_index = index
        if first_match == absurd_match:
            return -1
        self.start = first_match
        self.match = the_match
        self.end = self.match.end()
        return best_index

def which (filename):

    """This takes a given filename; tries to find it in the environment path;
    then checks if it is executable. This returns the full path to the filename
    if found and executable. Otherwise this returns None."""

    # Special case where filename already contains a path.
    if os.path.dirname(filename) != '':
        if os.access (filename, os.X_OK):
            return filename

    if not os.environ.has_key('PATH') or os.environ['PATH'] == '':
        p = os.defpath
    else:
        p = os.environ['PATH']

    # Oddly enough this was the one line that made Pexpect
    # incompatible with Python 1.5.2.
    #pathlist = p.split (os.pathsep)
    pathlist = string.split (p, os.pathsep)

    for path in pathlist:
        f = os.path.join(path, filename)
        if os.access(f, os.X_OK):
            return f
    return None

def split_command_line(command_line):

    """This splits a command line into a list of arguments. It splits arguments
    on spaces, but handles embedded quotes, doublequotes, and escaped
    characters. It's impossible to do this with a regular expression, so I
    wrote a little state machine to parse the command line. """

    arg_list = []
    arg = ''

    # Constants to name the states we can be in.
    state_basic = 0
    state_esc = 1
    state_singlequote = 2
    state_doublequote = 3
    state_whitespace = 4 # The state of consuming whitespace between commands.
    state = state_basic

    for c in command_line:
        if state == state_basic or state == state_whitespace:
            if c == '\\': # Escape the next character
                state = state_esc
            elif c == r"'": # Handle single quote
                state = state_singlequote
            elif c == r'"': # Handle double quote
                state = state_doublequote
            elif c.isspace():
                # Add arg to arg_list if we aren't in the middle of whitespace.
                if state == state_whitespace:
                    None # Do nothing.
                else:
                    arg_list.append(arg)
                    arg = ''
                    state = state_whitespace
            else:
                arg = arg + c
                state = state_basic
        elif state == state_esc:
            arg = arg + c
            state = state_basic
        elif state == state_singlequote:
            if c == r"'":
                state = state_basic
            else:
                arg = arg + c
        elif state == state_doublequote:
            if c == r'"':
                state = state_basic
            else:
                arg = arg + c

    if arg != '':
        arg_list.append(arg)
    return arg_list

# vi:ts=4:sw=4:expandtab:ft=python: