lib/libc/time/tzselect.ksh

   1 #! /bin/bash
   2 #
   3 #       $NetBSD: tzselect.ksh,v 1.14 2015/06/21 16:06:51 christos Exp $
   4 #
   5 PKGVERSION='(tzcode) '
   6 TZVERSION=see_Makefile
   7 REPORT_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 '-'.
  44 say() {
  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
  55 coord=
  56 location_limit=10
  57 zonetabtype=zone1970
  58
  59 usage="Usage: tzselect [--version] [--help] [-c COORD] [-n LIMIT]
  60 Select a time zone interactively.
  61
  62 Options:
  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
  81 Report 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.
  87 if
  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
  94 then
  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   '
 116 else
 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   }
 149 fi
 150
 151 while getopts c:n:t:-: opt
 152 do
 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
 169 done
 170
 171 shift `expr $OPTIND - 1`
 172 case $# in
 173 0) ;;
 174 *) say >&2 "$0: $1: unknown argument"; exit 1 ;;
 175 esac
 176
 177 # Make sure the tables are readable.
 178 TZ_COUNTRY_TABLE=$TZDIR/iso3166.tab
 179 TZ_ZONE_TABLE=$TZDIR/$zonetabtype.tab
 180 for f in $TZ_COUNTRY_TABLE $TZ_ZONE_TABLE
 181 do
 182         <"$f" || {
 183                 say >&2 "$0: time zone files are not set up correctly"
 184                 exit 1
 185         }
 186 done
 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/$zonetabtype.tab
 202
 203 newline='
 204 '
 205 IFS=$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'.
 210 output_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.
 294 while
 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="
 514 Local time is now:      $TZdate.
 515 Universal 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
 542 do coord=
 543 done
 544
 545 case $SHELL in
 546 *csh) file=.login line="setenv TZ '$TZ'";;
 547 *) file=.profile line="TZ='$TZ'; export TZ"
 548 esac
 549
 550 say >&2 "
 551 You can make this change permanent for yourself by appending the line
 552         $line
 553 to the file '$file' in your home directory; then log out and log in again.
 554
 555 Here is that TZ value again, this time on standard output so that you
 556 can use the $0 command in shell scripts:"
 557
 558 say "$TZ"