This file is indexed.

/usr/bin/tzselect is in libc-bin 2.19-18+deb8u10.

This file is owned by root:root, with mode 0o755.

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
#!/bin/bash

PKGVERSION="(Debian GLIBC 2.19-18+deb8u10) "
TZVERSION="2.19"
REPORT_BUGS_TO="<http://www.debian.org/Bugs/>"

# Ask the user about the time zone, and output the resulting TZ value to stdout.
# Interact with the user via stderr and stdin.

# Contributed by Paul Eggert.

# Porting notes:
#
# This script requires a Posix-like shell and prefers the extension of a
# 'select' statement.  The 'select' statement was introduced in the
# Korn shell and is available in Bash and other shell implementations.
# If your host lacks both Bash and the Korn shell, you can get their
# source from one of these locations:
#
#	Bash <http://www.gnu.org/software/bash/bash.html>
#	Korn Shell <http://www.kornshell.com/>
#	Public Domain Korn Shell <http://www.cs.mun.ca/~michael/pdksh/>
#
# For portability to Solaris 9 /bin/sh this script avoids some POSIX
# features and common extensions, such as $(...) (which works sometimes
# but not others), $((...)), and $10.
#
# This script also uses several features of modern awk programs.
# If your host lacks awk, or has an old awk that does not conform to Posix,
# you can use either of the following free programs instead:
#
#	Gawk (GNU awk) <http://www.gnu.org/software/gawk/>
#	mawk <http://invisible-island.net/mawk/>


# Specify default values for environment variables if they are unset.
: ${AWK=awk}
: ${TZDIR=/usr/share/zoneinfo}

# Check for awk Posix compliance.
($AWK -v x=y 'BEGIN { exit 123 }') </dev/null >/dev/null 2>&1
[ $? = 123 ] || {
	echo >&2 "$0: Sorry, your \`$AWK' program is not Posix compatible."
	exit 1
}

coord=
location_limit=10

usage="Usage: tzselect [--version] [--help] [-c COORD] [-n LIMIT]
Select a time zone interactively.

Options:

  -c COORD
    Instead of asking for continent and then country and then city,
    ask for selection from time zones whose largest cities
    are closest to the location with geographical coordinates COORD.
    COORD should use ISO 6709 notation, for example, '-c +4852+00220'
    for Paris (in degrees and minutes, North and East), or
    '-c -35-058' for Buenos Aires (in degrees, South and West).

  -n LIMIT
    Display at most LIMIT locations when -c is used (default $location_limit).

  --version
    Output version information.

  --help
    Output this help.

Report bugs to $REPORT_BUGS_TO."

# Ask the user to select from the function's arguments,
# and assign the selected argument to the variable 'select_result'.
# Exit on EOF or I/O error.  Use the shell's 'select' builtin if available,
# falling back on a less-nice but portable substitute otherwise.
if
  case $BASH_VERSION in
  ?*) : ;;
  '')
    # '; exit' should be redundant, but Dash doesn't properly fail without it.
    (eval 'set --; select x; do break; done; exit') 2>/dev/null
  esac
then
  # Do this inside 'eval', as otherwise the shell might exit when parsing it
  # even though it is never executed.
  eval '
    doselect() {
      select select_result
      do
	case $select_result in
	"") echo >&2 "Please enter a number in range." ;;
	?*) break
	esac
      done || exit
    }

    # Work around a bug in bash 1.14.7 and earlier, where $PS3 is sent to stdout.
    case $BASH_VERSION in
    [01].*)
      case `echo 1 | (select x in x; do break; done) 2>/dev/null` in
      ?*) PS3=
      esac
    esac
  '
else
  doselect() {
    # Field width of the prompt numbers.
    select_width=`expr $# : '.*'`

    select_i=

    while :
    do
      case $select_i in
      '')
	select_i=0
	for select_word
	do
	  select_i=`expr $select_i + 1`
	  printf >&2 "%${select_width}d) %s\\n" $select_i "$select_word"
	done ;;
      *[!0-9]*)
	echo >&2 'Please enter a number in range.' ;;
      *)
	if test 1 -le $select_i && test $select_i -le $#; then
	  shift `expr $select_i - 1`
	  select_result=$1
	  break
	fi
	echo >&2 'Please enter a number in range.'
      esac

      # Prompt and read input.
      printf >&2 %s "${PS3-#? }"
      read select_i || exit
    done
  }
fi

while getopts c:n:-: opt
do
    case $opt$OPTARG in
    c*)
	coord=$OPTARG ;;
    n*)
	location_limit=$OPTARG ;;
    -help)
	exec echo "$usage" ;;
    -version)
	exec echo "tzselect $PKGVERSION$TZVERSION" ;;
    -*)
	echo >&2 "$0: -$opt$OPTARG: unknown option; try '$0 --help'"; exit 1 ;;
    *)
	echo >&2 "$0: try '$0 --help'"; exit 1 ;;
    esac
done

shift `expr $OPTIND - 1`
case $# in
0) ;;
*) echo >&2 "$0: $1: unknown argument"; exit 1 ;;
esac

# Make sure the tables are readable.
TZ_COUNTRY_TABLE=$TZDIR/iso3166.tab
TZ_ZONE_TABLE=$TZDIR/zone.tab
for f in $TZ_COUNTRY_TABLE $TZ_ZONE_TABLE
do
	<$f || {
		echo >&2 "$0: time zone files are not set up correctly"
		exit 1
	}
done

newline='
'
IFS=$newline


# Awk script to read a time zone table and output the same table,
# with each column preceded by its distance from 'here'.
output_distances='
  BEGIN {
    FS = "\t"
    while (getline <TZ_COUNTRY_TABLE)
      if ($0 ~ /^[^#]/)
        country[$1] = $2
    country["US"] = "US" # Otherwise the strings get too long.
  }
  function convert_coord(coord, deg, min, ilen, sign, sec) {
    if (coord ~ /^[-+]?[0-9]?[0-9][0-9][0-9][0-9][0-9][0-9]([^0-9]|$)/) {
      degminsec = coord
      intdeg = degminsec < 0 ? -int(-degminsec / 10000) : int(degminsec / 10000)
      minsec = degminsec - intdeg * 10000
      intmin = minsec < 0 ? -int(-minsec / 100) : int(minsec / 100)
      sec = minsec - intmin * 100
      deg = (intdeg * 3600 + intmin * 60 + sec) / 3600
    } else if (coord ~ /^[-+]?[0-9]?[0-9][0-9][0-9][0-9]([^0-9]|$)/) {
      degmin = coord
      intdeg = degmin < 0 ? -int(-degmin / 100) : int(degmin / 100)
      min = degmin - intdeg * 100
      deg = (intdeg * 60 + min) / 60
    } else
      deg = coord
    return deg * 0.017453292519943296
  }
  function convert_latitude(coord) {
    match(coord, /..*[-+]/)
    return convert_coord(substr(coord, 1, RLENGTH - 1))
  }
  function convert_longitude(coord) {
    match(coord, /..*[-+]/)
    return convert_coord(substr(coord, RLENGTH))
  }
  # Great-circle distance between points with given latitude and longitude.
  # Inputs and output are in radians.  This uses the great-circle special
  # case of the Vicenty formula for distances on ellipsoids.
  function dist(lat1, long1, lat2, long2, dlong, x, y, num, denom) {
    dlong = long2 - long1
    x = cos (lat2) * sin (dlong)
    y = cos (lat1) * sin (lat2) - sin (lat1) * cos (lat2) * cos (dlong)
    num = sqrt (x * x + y * y)
    denom = sin (lat1) * sin (lat2) + cos (lat1) * cos (lat2) * cos (dlong)
    return atan2(num, denom)
  }
  BEGIN {
    coord_lat = convert_latitude(coord)
    coord_long = convert_longitude(coord)
  }
  /^[^#]/ {
    here_lat = convert_latitude($2)
    here_long = convert_longitude($2)
    line = $1 "\t" $2 "\t" $3 "\t" country[$1]
    if (NF == 4)
      line = line " - " $4
    printf "%g\t%s\n", dist(coord_lat, coord_long, here_lat, here_long), line
  }
'

# Begin the main loop.  We come back here if the user wants to retry.
while

	echo >&2 'Please identify a location' \
		'so that time zone rules can be set correctly.'

	continent=
	country=
	region=

	case $coord in
	?*)
		continent=coord;;
	'')

	# Ask the user for continent or ocean.

	echo >&2 'Please select a continent, ocean, "coord", or "TZ".'

        quoted_continents=`
	  $AWK '
	    BEGIN { FS = "\t" }
	    /^[^#]/ {
              entry = substr($3, 1, index($3, "/") - 1)
              if (entry == "America")
		entry = entry "s"
              if (entry ~ /^(Arctic|Atlantic|Indian|Pacific)$/)
		entry = entry " Ocean"
              printf "'\''%s'\''\n", entry
            }
          ' $TZ_ZONE_TABLE |
	  sort -u |
	  tr '\n' ' '
	  echo ''
	`

	eval '
	    doselect '"$quoted_continents"' \
		"coord - I want to use geographical coordinates." \
		"TZ - I want to specify the time zone using the Posix TZ format."
	    continent=$select_result
	    case $continent in
	    Americas) continent=America;;
	    *" "*) continent=`expr "$continent" : '\''\([^ ]*\)'\''`
	    esac
	'
	esac

	case $continent in
	TZ)
		# Ask the user for a Posix TZ string.  Check that it conforms.
		while
			echo >&2 'Please enter the desired value' \
				'of the TZ environment variable.'
			echo >&2 'For example, GST-10 is a zone named GST' \
				'that is 10 hours ahead (east) of UTC.'
			read TZ
			$AWK -v TZ="$TZ" 'BEGIN {
				tzname = "[^-+,0-9][^-+,0-9][^-+,0-9]+"
				time = "[0-2]?[0-9](:[0-5][0-9](:[0-5][0-9])?)?"
				offset = "[-+]?" time
				date = "(J?[0-9]+|M[0-9]+\.[0-9]+\.[0-9]+)"
				datetime = "," date "(/" time ")?"
				tzpattern = "^(:.*|" tzname offset "(" tzname \
				  "(" offset ")?(" datetime datetime ")?)?)$"
				if (TZ ~ tzpattern) exit 1
				exit 0
			}'
		do
			echo >&2 "\`$TZ' is not a conforming" \
				'Posix time zone string.'
		done
		TZ_for_date=$TZ;;
	*)
		case $continent in
		coord)
		    case $coord in
		    '')
			echo >&2 'Please enter coordinates' \
				'in ISO 6709 notation.'
			echo >&2 'For example, +4042-07403 stands for'
			echo >&2 '40 degrees 42 minutes north,' \
				'74 degrees 3 minutes west.'
			read coord;;
		    esac
		    distance_table=`$AWK \
			    -v coord="$coord" \
			    -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
			    "$output_distances" <$TZ_ZONE_TABLE |
		      sort -n |
		      sed "${location_limit}q"
		    `
		    regions=`echo "$distance_table" | $AWK '
		      BEGIN { FS = "\t" }
		      { print $NF }
		    '`
		    echo >&2 'Please select one of the following' \
			    'time zone regions,'
		    echo >&2 'listed roughly in increasing order' \
			    "of distance from $coord".
		    doselect $regions
		    region=$select_result
		    TZ=`echo "$distance_table" | $AWK -v region="$region" '
		      BEGIN { FS="\t" }
		      $NF == region { print $4 }
		    '`
		    ;;
		*)
		# Get list of names of countries in the continent or ocean.
		countries=`$AWK \
			-v continent="$continent" \
			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
		'
			BEGIN { FS = "\t" }
			/^#/ { next }
			$3 ~ ("^" continent "/") {
				if (!cc_seen[$1]++) cc_list[++ccs] = $1
			}
			END {
				while (getline <TZ_COUNTRY_TABLE) {
					if ($0 !~ /^#/) cc_name[$1] = $2
				}
				for (i = 1; i <= ccs; i++) {
					country = cc_list[i]
					if (cc_name[country]) {
					  country = cc_name[country]
					}
					print country
				}
			}
		' <$TZ_ZONE_TABLE | sort -f`


		# If there's more than one country, ask the user which one.
		case $countries in
		*"$newline"*)
			echo >&2 'Please select a country' \
				'whose clocks agree with yours.'
			doselect $countries
			country=$select_result;;
		*)
			country=$countries
		esac


		# Get list of names of time zone rule regions in the country.
		regions=`$AWK \
			-v country="$country" \
			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
		'
			BEGIN {
				FS = "\t"
				cc = country
				while (getline <TZ_COUNTRY_TABLE) {
					if ($0 !~ /^#/  &&  country == $2) {
						cc = $1
						break
					}
				}
			}
			$1 == cc { print $4 }
		' <$TZ_ZONE_TABLE`


		# If there's more than one region, ask the user which one.
		case $regions in
		*"$newline"*)
			echo >&2 'Please select one of the following' \
				'time zone regions.'
			doselect $regions
			region=$select_result;;
		*)
			region=$regions
		esac

		# Determine TZ from country and region.
		TZ=`$AWK \
			-v country="$country" \
			-v region="$region" \
			-v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \
		'
			BEGIN {
				FS = "\t"
				cc = country
				while (getline <TZ_COUNTRY_TABLE) {
					if ($0 !~ /^#/  &&  country == $2) {
						cc = $1
						break
					}
				}
			}
			$1 == cc && $4 == region { print $3 }
		' <$TZ_ZONE_TABLE`
		esac

		# Make sure the corresponding zoneinfo file exists.
		TZ_for_date=$TZDIR/$TZ
		<$TZ_for_date || {
			echo >&2 "$0: time zone files are not set up correctly"
			exit 1
		}
	esac


	# Use the proposed TZ to output the current date relative to UTC.
	# Loop until they agree in seconds.
	# Give up after 8 unsuccessful tries.

	extra_info=
	for i in 1 2 3 4 5 6 7 8
	do
		TZdate=`LANG=C TZ="$TZ_for_date" date`
		UTdate=`LANG=C TZ=UTC0 date`
		TZsec=`expr "$TZdate" : '.*:\([0-5][0-9]\)'`
		UTsec=`expr "$UTdate" : '.*:\([0-5][0-9]\)'`
		case $TZsec in
		$UTsec)
			extra_info="
Local time is now:	$TZdate.
Universal Time is now:	$UTdate."
			break
		esac
	done


	# Output TZ info and ask the user to confirm.

	echo >&2 ""
	echo >&2 "The following information has been given:"
	echo >&2 ""
	case $country%$region%$coord in
	?*%?*%)	echo >&2 "	$country$newline	$region";;
	?*%%)	echo >&2 "	$country";;
	%?*%?*) echo >&2 "	coord $coord$newline	$region";;
	%%?*)	echo >&2 "	coord $coord";;
	+)	echo >&2 "	TZ='$TZ'"
	esac
	echo >&2 ""
	echo >&2 "Therefore TZ='$TZ' will be used.$extra_info"
	echo >&2 "Is the above information OK?"

	doselect Yes No
	ok=$select_result
	case $ok in
	Yes) break
	esac
do coord=
done

case $SHELL in
*csh) file=.login line="setenv TZ '$TZ'";;
*) file=.profile line="TZ='$TZ'; export TZ"
esac

echo >&2 "
You can make this change permanent for yourself by appending the line
	$line
to the file '$file' in your home directory; then log out and log in again.

Here is that TZ value again, this time on standard output so that you
can use the $0 command in shell scripts:"

echo "$TZ"