1#! /bin/bash 2# 3# $NetBSD: tzselect.ksh,v 1.14 2015/06/21 16:06:51 christos Exp $ 4# 5PKGVERSION='(tzcode) ' 6TZVERSION=see_Makefile 7REPORT_BUGS_TO=tz@iana.org 8 9# Ask the user about the time zone, and output the resulting TZ value to stdout. 10# Interact with the user via stderr and stdin. 11 12# Contributed by Paul Eggert. 13 14# Porting notes: 15# 16# This script requires a Posix-like shell and prefers the extension of a 17# 'select' statement. The 'select' statement was introduced in the 18# Korn shell and is available in Bash and other shell implementations. 19# If your host lacks both Bash and the Korn shell, you can get their 20# source from one of these locations: 21# 22# Bash <http://www.gnu.org/software/bash/bash.html> 23# Korn Shell <http://www.kornshell.com/> 24# Public Domain Korn Shell <http://www.cs.mun.ca/~michael/pdksh/> 25# 26# For portability to Solaris 9 /bin/sh this script avoids some POSIX 27# features and common extensions, such as $(...) (which works sometimes 28# but not others), $((...)), and $10. 29# 30# This script also uses several features of modern awk programs. 31# If your host lacks awk, or has an old awk that does not conform to Posix, 32# you can use either of the following free programs instead: 33# 34# Gawk (GNU awk) <http://www.gnu.org/software/gawk/> 35# mawk <http://invisible-island.net/mawk/> 36 37 38# Specify default values for environment variables if they are unset. 39: ${AWK=awk} 40: ${TZDIR=`pwd`} 41 42# Output one argument as-is to standard output. 43# Safer than 'echo', which can mishandle '\' or leading '-'. 44say() { 45 printf '%s\n' "$1" 46} 47 48# Check for awk Posix compliance. 49($AWK -v x=y 'BEGIN { exit 123 }') </dev/null >/dev/null 2>&1 50[ $? = 123 ] || { 51 say >&2 "$0: Sorry, your '$AWK' program is not Posix compatible." 52 exit 1 53} 54 55coord= 56location_limit=10 57zonetabtype=zone1970 58 59usage="Usage: tzselect [--version] [--help] [-c COORD] [-n LIMIT] 60Select a time zone interactively. 61 62Options: 63 64 -c COORD 65 Instead of asking for continent and then country and then city, 66 ask for selection from time zones whose largest cities 67 are closest to the location with geographical coordinates COORD. 68 COORD should use ISO 6709 notation, for example, '-c +4852+00220' 69 for Paris (in degrees and minutes, North and East), or 70 '-c -35-058' for Buenos Aires (in degrees, South and West). 71 72 -n LIMIT 73 Display at most LIMIT locations when -c is used (default $location_limit). 74 75 --version 76 Output version information. 77 78 --help 79 Output this help. 80 81Report bugs to $REPORT_BUGS_TO." 82 83# Ask the user to select from the function's arguments, 84# and assign the selected argument to the variable 'select_result'. 85# Exit on EOF or I/O error. Use the shell's 'select' builtin if available, 86# falling back on a less-nice but portable substitute otherwise. 87if 88 case $BASH_VERSION in 89 ?*) : ;; 90 '') 91 # '; exit' should be redundant, but Dash doesn't properly fail without it. 92 (eval 'set --; select x; do break; done; exit') </dev/null 2>/dev/null 93 esac 94then 95 # Do this inside 'eval', as otherwise the shell might exit when parsing it 96 # even though it is never executed. 97 eval ' 98 doselect() { 99 select select_result 100 do 101 case $select_result in 102 "") echo >&2 "Please enter a number in range." ;; 103 ?*) break 104 esac 105 done || exit 106 } 107 108 # Work around a bug in bash 1.14.7 and earlier, where $PS3 is sent to stdout. 109 case $BASH_VERSION in 110 [01].*) 111 case `echo 1 | (select x in x; do break; done) 2>/dev/null` in 112 ?*) PS3= 113 esac 114 esac 115 ' 116else 117 doselect() { 118 # Field width of the prompt numbers. 119 select_width=`expr $# : '.*'` 120 121 select_i= 122 123 while : 124 do 125 case $select_i in 126 '') 127 select_i=0 128 for select_word 129 do 130 select_i=`expr $select_i + 1` 131 printf >&2 "%${select_width}d) %s\\n" $select_i "$select_word" 132 done ;; 133 *[!0-9]*) 134 echo >&2 'Please enter a number in range.' ;; 135 *) 136 if test 1 -le $select_i && test $select_i -le $#; then 137 shift `expr $select_i - 1` 138 select_result=$1 139 break 140 fi 141 echo >&2 'Please enter a number in range.' 142 esac 143 144 # Prompt and read input. 145 printf >&2 %s "${PS3-#? }" 146 read select_i || exit 147 done 148 } 149fi 150 151while getopts c:n:t:-: opt 152do 153 case $opt$OPTARG in 154 c*) 155 coord=$OPTARG ;; 156 n*) 157 location_limit=$OPTARG ;; 158 t*) # Undocumented option, used for developer testing. 159 zonetabtype=$OPTARG ;; 160 -help) 161 exec echo "$usage" ;; 162 -version) 163 exec echo "tzselect $PKGVERSION$TZVERSION" ;; 164 -*) 165 say >&2 "$0: -$opt$OPTARG: unknown option; try '$0 --help'"; exit 1 ;; 166 *) 167 say >&2 "$0: try '$0 --help'"; exit 1 ;; 168 esac 169done 170 171shift `expr $OPTIND - 1` 172case $# in 1730) ;; 174*) say >&2 "$0: $1: unknown argument"; exit 1 ;; 175esac 176 177# Make sure the tables are readable. 178TZ_COUNTRY_TABLE=$TZDIR/iso3166.tab 179TZ_ZONE_TABLE=$TZDIR/$zonetabtype.tab 180for f in $TZ_COUNTRY_TABLE $TZ_ZONE_TABLE 181do 182 <"$f" || { 183 say >&2 "$0: time zone files are not set up correctly" 184 exit 1 185 } 186done 187 188# If the current locale does not support UTF-8, convert data to current 189# locale's format if possible, as the shell aligns columns better that way. 190# Check the UTF-8 of U+12345 CUNEIFORM SIGN URU TIMES KI. 191! $AWK 'BEGIN { u12345 = "\360\222\215\205"; exit length(u12345) != 1 }' && 192 { tmp=`(mktemp -d) 2>/dev/null` || { 193 tmp=${TMPDIR-/tmp}/tzselect.$$ && 194 (umask 77 && mkdir -- "$tmp") 195 };} && 196 trap 'status=$?; rm -fr -- "$tmp"; exit $status' 0 HUP INT PIPE TERM && 197 (iconv -f UTF-8 -t //TRANSLIT <"$TZ_COUNTRY_TABLE" >$tmp/iso3166.tab) \ 198 2>/dev/null && 199 TZ_COUNTRY_TABLE=$tmp/iso3166.tab && 200 iconv -f UTF-8 -t //TRANSLIT <"$TZ_ZONE_TABLE" >$tmp/$zonetabtype.tab && 201 TZ_ZONE_TABLE=$tmp/$zonetabtype.tab 202 203newline=' 204' 205IFS=$newline 206 207 208# Awk script to read a time zone table and output the same table, 209# with each column preceded by its distance from 'here'. 210output_distances=' 211 BEGIN { 212 FS = "\t" 213 while (getline <TZ_COUNTRY_TABLE) 214 if ($0 ~ /^[^#]/) 215 country[$1] = $2 216 country["US"] = "US" # Otherwise the strings get too long. 217 } 218 function abs(x) { 219 return x < 0 ? -x : x; 220 } 221 function min(x, y) { 222 return x < y ? x : y; 223 } 224 function convert_coord(coord, deg, minute, ilen, sign, sec) { 225 if (coord ~ /^[-+]?[0-9]?[0-9][0-9][0-9][0-9][0-9][0-9]([^0-9]|$)/) { 226 degminsec = coord 227 intdeg = degminsec < 0 ? -int(-degminsec / 10000) : int(degminsec / 10000) 228 minsec = degminsec - intdeg * 10000 229 intmin = minsec < 0 ? -int(-minsec / 100) : int(minsec / 100) 230 sec = minsec - intmin * 100 231 deg = (intdeg * 3600 + intmin * 60 + sec) / 3600 232 } else if (coord ~ /^[-+]?[0-9]?[0-9][0-9][0-9][0-9]([^0-9]|$)/) { 233 degmin = coord 234 intdeg = degmin < 0 ? -int(-degmin / 100) : int(degmin / 100) 235 minute = degmin - intdeg * 100 236 deg = (intdeg * 60 + minute) / 60 237 } else 238 deg = coord 239 return deg * 0.017453292519943296 240 } 241 function convert_latitude(coord) { 242 match(coord, /..*[-+]/) 243 return convert_coord(substr(coord, 1, RLENGTH - 1)) 244 } 245 function convert_longitude(coord) { 246 match(coord, /..*[-+]/) 247 return convert_coord(substr(coord, RLENGTH)) 248 } 249 # Great-circle distance between points with given latitude and longitude. 250 # Inputs and output are in radians. This uses the great-circle special 251 # case of the Vicenty formula for distances on ellipsoids. 252 function gcdist(lat1, long1, lat2, long2, dlong, x, y, num, denom) { 253 dlong = long2 - long1 254 x = cos(lat2) * sin(dlong) 255 y = cos(lat1) * sin(lat2) - sin(lat1) * cos(lat2) * cos(dlong) 256 num = sqrt(x * x + y * y) 257 denom = sin(lat1) * sin(lat2) + cos(lat1) * cos(lat2) * cos(dlong) 258 return atan2(num, denom) 259 } 260 # Parallel distance between points with given latitude and longitude. 261 # This is the product of the longitude difference and the cosine 262 # of the latitude of the point that is further from the equator. 263 # I.e., it considers longitudes to be further apart if they are 264 # nearer the equator. 265 function pardist(lat1, long1, lat2, long2) { 266 return abs(long1 - long2) * min(cos(lat1), cos(lat2)) 267 } 268 # The distance function is the sum of the great-circle distance and 269 # the parallel distance. It could be weighted. 270 function dist(lat1, long1, lat2, long2) { 271 return gcdist(lat1, long1, lat2, long2) + pardist(lat1, long1, lat2, long2) 272 } 273 BEGIN { 274 coord_lat = convert_latitude(coord) 275 coord_long = convert_longitude(coord) 276 } 277 /^[^#]/ { 278 here_lat = convert_latitude($2) 279 here_long = convert_longitude($2) 280 line = $1 "\t" $2 "\t" $3 281 sep = "\t" 282 ncc = split($1, cc, /,/) 283 for (i = 1; i <= ncc; i++) { 284 line = line sep country[cc[i]] 285 sep = ", " 286 } 287 if (NF == 4) 288 line = line " - " $4 289 printf "%g\t%s\n", dist(coord_lat, coord_long, here_lat, here_long), line 290 } 291' 292 293# Begin the main loop. We come back here if the user wants to retry. 294while 295 296 echo >&2 'Please identify a location' \ 297 'so that time zone rules can be set correctly.' 298 299 continent= 300 country= 301 region= 302 303 case $coord in 304 ?*) 305 continent=coord;; 306 '') 307 308 # Ask the user for continent or ocean. 309 310 echo >&2 'Please select a continent, ocean, "coord", or "TZ".' 311 312 quoted_continents=` 313 $AWK ' 314 BEGIN { FS = "\t" } 315 /^[^#]/ { 316 entry = substr($3, 1, index($3, "/") - 1) 317 if (entry == "America") 318 entry = entry "s" 319 if (entry ~ /^(Arctic|Atlantic|Indian|Pacific)$/) 320 entry = entry " Ocean" 321 printf "'\''%s'\''\n", entry 322 } 323 ' <"$TZ_ZONE_TABLE" | 324 sort -u | 325 tr '\n' ' ' 326 echo '' 327 ` 328 329 eval ' 330 doselect '"$quoted_continents"' \ 331 "coord - I want to use geographical coordinates." \ 332 "TZ - I want to specify the time zone using the Posix TZ format." 333 continent=$select_result 334 case $continent in 335 Americas) continent=America;; 336 *" "*) continent=`expr "$continent" : '\''\([^ ]*\)'\''` 337 esac 338 ' 339 esac 340 341 case $continent in 342 TZ) 343 # Ask the user for a Posix TZ string. Check that it conforms. 344 while 345 echo >&2 'Please enter the desired value' \ 346 'of the TZ environment variable.' 347 echo >&2 'For example, GST-10 is a zone named GST' \ 348 'that is 10 hours ahead (east) of UTC.' 349 read TZ 350 $AWK -v TZ="$TZ" 'BEGIN { 351 tzname = "[^-+,0-9][^-+,0-9][^-+,0-9]+" 352 time = "[0-2]?[0-9](:[0-5][0-9](:[0-5][0-9])?)?" 353 offset = "[-+]?" time 354 date = "(J?[0-9]+|M[0-9]+\\.[0-9]+\\.[0-9]+)" 355 datetime = "," date "(/" time ")?" 356 tzpattern = "^(:.*|" tzname offset "(" tzname \ 357 "(" offset ")?(" datetime datetime ")?)?)$" 358 if (TZ ~ tzpattern) exit 1 359 exit 0 360 }' 361 do 362 say >&2 "'$TZ' is not a conforming Posix time zone string." 363 done 364 TZ_for_date=$TZ;; 365 *) 366 case $continent in 367 coord) 368 case $coord in 369 '') 370 echo >&2 'Please enter coordinates' \ 371 'in ISO 6709 notation.' 372 echo >&2 'For example, +4042-07403 stands for' 373 echo >&2 '40 degrees 42 minutes north,' \ 374 '74 degrees 3 minutes west.' 375 read coord;; 376 esac 377 distance_table=`$AWK \ 378 -v coord="$coord" \ 379 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \ 380 "$output_distances" <"$TZ_ZONE_TABLE" | 381 sort -n | 382 sed "${location_limit}q" 383 ` 384 regions=`say "$distance_table" | $AWK ' 385 BEGIN { FS = "\t" } 386 { print $NF } 387 '` 388 echo >&2 'Please select one of the following' \ 389 'time zone regions,' 390 echo >&2 'listed roughly in increasing order' \ 391 "of distance from $coord". 392 doselect $regions 393 region=$select_result 394 TZ=`say "$distance_table" | $AWK -v region="$region" ' 395 BEGIN { FS="\t" } 396 $NF == region { print $4 } 397 '` 398 ;; 399 *) 400 # Get list of names of countries in the continent or ocean. 401 countries=`$AWK \ 402 -v continent="$continent" \ 403 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \ 404 ' 405 BEGIN { FS = "\t" } 406 /^#/ { next } 407 $3 ~ ("^" continent "/") { 408 ncc = split($1, cc, /,/) 409 for (i = 1; i <= ncc; i++) 410 if (!cc_seen[cc[i]]++) cc_list[++ccs] = cc[i] 411 } 412 END { 413 while (getline <TZ_COUNTRY_TABLE) { 414 if ($0 !~ /^#/) cc_name[$1] = $2 415 } 416 for (i = 1; i <= ccs; i++) { 417 country = cc_list[i] 418 if (cc_name[country]) { 419 country = cc_name[country] 420 } 421 print country 422 } 423 } 424 ' <"$TZ_ZONE_TABLE" | sort -f` 425 426 427 # If there's more than one country, ask the user which one. 428 case $countries in 429 *"$newline"*) 430 echo >&2 'Please select a country' \ 431 'whose clocks agree with yours.' 432 doselect $countries 433 country=$select_result;; 434 *) 435 country=$countries 436 esac 437 438 439 # Get list of names of time zone rule regions in the country. 440 regions=`$AWK \ 441 -v country="$country" \ 442 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \ 443 ' 444 BEGIN { 445 FS = "\t" 446 cc = country 447 while (getline <TZ_COUNTRY_TABLE) { 448 if ($0 !~ /^#/ && country == $2) { 449 cc = $1 450 break 451 } 452 } 453 } 454 /^#/ { next } 455 $1 ~ cc { print $4 } 456 ' <"$TZ_ZONE_TABLE"` 457 458 459 # If there's more than one region, ask the user which one. 460 case $regions in 461 *"$newline"*) 462 echo >&2 'Please select one of the following' \ 463 'time zone regions.' 464 doselect $regions 465 region=$select_result;; 466 *) 467 region=$regions 468 esac 469 470 # Determine TZ from country and region. 471 TZ=`$AWK \ 472 -v country="$country" \ 473 -v region="$region" \ 474 -v TZ_COUNTRY_TABLE="$TZ_COUNTRY_TABLE" \ 475 ' 476 BEGIN { 477 FS = "\t" 478 cc = country 479 while (getline <TZ_COUNTRY_TABLE) { 480 if ($0 !~ /^#/ && country == $2) { 481 cc = $1 482 break 483 } 484 } 485 } 486 /^#/ { next } 487 $1 ~ cc && $4 == region { print $3 } 488 ' <"$TZ_ZONE_TABLE"` 489 esac 490 491 # Make sure the corresponding zoneinfo file exists. 492 TZ_for_date=$TZDIR/$TZ 493 <"$TZ_for_date" || { 494 say >&2 "$0: time zone files are not set up correctly" 495 exit 1 496 } 497 esac 498 499 500 # Use the proposed TZ to output the current date relative to UTC. 501 # Loop until they agree in seconds. 502 # Give up after 8 unsuccessful tries. 503 504 extra_info= 505 for i in 1 2 3 4 5 6 7 8 506 do 507 TZdate=`LANG=C TZ="$TZ_for_date" date` 508 UTdate=`LANG=C TZ=UTC0 date` 509 TZsec=`expr "$TZdate" : '.*:\([0-5][0-9]\)'` 510 UTsec=`expr "$UTdate" : '.*:\([0-5][0-9]\)'` 511 case $TZsec in 512 $UTsec) 513 extra_info=" 514Local time is now: $TZdate. 515Universal Time is now: $UTdate." 516 break 517 esac 518 done 519 520 521 # Output TZ info and ask the user to confirm. 522 523 echo >&2 "" 524 echo >&2 "The following information has been given:" 525 echo >&2 "" 526 case $country%$region%$coord in 527 ?*%?*%) say >&2 " $country$newline $region";; 528 ?*%%) say >&2 " $country";; 529 %?*%?*) say >&2 " coord $coord$newline $region";; 530 %%?*) say >&2 " coord $coord";; 531 *) say >&2 " TZ='$TZ'" 532 esac 533 say >&2 "" 534 say >&2 "Therefore TZ='$TZ' will be used.$extra_info" 535 say >&2 "Is the above information OK?" 536 537 doselect Yes No 538 ok=$select_result 539 case $ok in 540 Yes) break 541 esac 542do coord= 543done 544 545case $SHELL in 546*csh) file=.login line="setenv TZ '$TZ'";; 547*) file=.profile line="TZ='$TZ'; export TZ" 548esac 549 550say >&2 " 551You can make this change permanent for yourself by appending the line 552 $line 553to the file '$file' in your home directory; then log out and log in again. 554 555Here is that TZ value again, this time on standard output so that you 556can use the $0 command in shell scripts:" 557 558say "$TZ" 559