lib/mdate-sh

   1 #!/bin/sh
   2 # Get modification time of a file or directory and pretty-print it.
   3
   4 scriptversion=2017-09-22.02; # UTC
   5
   6 # Copyright (C) 1995-2017 Free Software Foundation, Inc.
   7 # written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, June 1995
   8 #
   9 # This program is free software; you can redistribute it and/or modify
  10 # it under the terms of the GNU General Public License as published by
  11 # the Free Software Foundation; either version 2, or (at your option)
  12 # any later version.
  13 #
  14 # This program is distributed in the hope that it will be useful,
  15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 # GNU General Public License for more details.
  18 #
  19 # You should have received a copy of the GNU General Public License
  20 # along with this program.  If not, see <https://www.gnu.org/licenses/>.
  21
  22 # As a special exception to the GNU General Public License, if you
  23 # distribute this file as part of a program that contains a
  24 # configuration script generated by Autoconf, you may include it under
  25 # the same distribution terms that you use for the rest of that program.
  26
  27 # This file is maintained in Automake, please report
  28 # bugs to <bug-automake@gnu.org> or send patches to
  29 # <automake-patches@gnu.org>.
  30
  31 if test -n "${ZSH_VERSION+set}" && (emulate sh) >/dev/null 2>&1; then
  32   emulate sh
  33   NULLCMD=:
  34   # Pre-4.2 versions of Zsh do word splitting on ${1+"$@"}, which
  35   # is contrary to our usage.  Disable this feature.
  36   alias -g '${1+"$@"}'='"$@"'
  37   setopt NO_GLOB_SUBST
  38 fi
  39
  40 case $1 in
  41   '')
  42      echo "$0: No file.  Try '$0 --help' for more information." 1>&2
  43      exit 1;
  44      ;;
  45   -h | --h*)
  46     cat <<\EOF
  47 Usage: mdate-sh [--help] [--version] FILE
  48
  49 Pretty-print the modification day of FILE, in the format:
  50 1 January 1970
  51
  52 Report bugs to <bug-automake@gnu.org>.
  53 EOF
  54     exit $?
  55     ;;
  56   -v | --v*)
  57     echo "mdate-sh $scriptversion"
  58     exit $?
  59     ;;
  60 esac
  61
  62 error ()
  63 {
  64   echo "$0: $1" >&2
  65   exit 1
  66 }
  67
  68
  69 # Prevent date giving response in another language.
  70 LANG=C
  71 export LANG
  72 LC_ALL=C
  73 export LC_ALL
  74 LC_TIME=C
  75 export LC_TIME
  76
  77 # Use UTC to get reproducible result.
  78 TZ=UTC0
  79 export TZ
  80
  81 # GNU ls changes its time format in response to the TIME_STYLE
  82 # variable.  Since we cannot assume 'unset' works, revert this
  83 # variable to its documented default.
  84 if test "${TIME_STYLE+set}" = set; then
  85   TIME_STYLE=posix-long-iso
  86   export TIME_STYLE
  87 fi
  88
  89 save_arg1=$1
  90
  91 # Find out how to get the extended ls output of a file or directory.
  92 if ls -L /dev/null 1>/dev/null 2>&1; then
  93   ls_command='ls -L -l -d'
  94 else
  95   ls_command='ls -l -d'
  96 fi
  97 # Avoid user/group names that might have spaces, when possible.
  98 if ls -n /dev/null 1>/dev/null 2>&1; then
  99   ls_command="$ls_command -n"
 100 fi
 101
 102 # A 'ls -l' line looks as follows on OS/2.
 103 #  drwxrwx---        0 Aug 11  2001 foo
 104 # This differs from Unix, which adds ownership information.
 105 #  drwxrwx---   2 root  root      4096 Aug 11  2001 foo
 106 #
 107 # To find the date, we split the line on spaces and iterate on words
 108 # until we find a month.  This cannot work with files whose owner is a
 109 # user named "Jan", or "Feb", etc.  However, it's unlikely that '/'
 110 # will be owned by a user whose name is a month.  So we first look at
 111 # the extended ls output of the root directory to decide how many
 112 # words should be skipped to get the date.
 113
 114 # On HPUX /bin/sh, "set" interprets "-rw-r--r--" as options, so the "x" below.
 115 set x`$ls_command /`
 116
 117 # Find which argument is the month.
 118 month=
 119 command=
 120 until test $month
 121 do
 122   test $# -gt 0 || error "failed parsing '$ls_command /' output"
 123   shift
 124   # Add another shift to the command.
 125   command="$command shift;"
 126   case $1 in
 127     Jan) month=January; nummonth=1;;
 128     Feb) month=February; nummonth=2;;
 129     Mar) month=March; nummonth=3;;
 130     Apr) month=April; nummonth=4;;
 131     May) month=May; nummonth=5;;
 132     Jun) month=June; nummonth=6;;
 133     Jul) month=July; nummonth=7;;
 134     Aug) month=August; nummonth=8;;
 135     Sep) month=September; nummonth=9;;
 136     Oct) month=October; nummonth=10;;
 137     Nov) month=November; nummonth=11;;
 138     Dec) month=December; nummonth=12;;
 139   esac
 140 done
 141
 142 test -n "$month" || error "failed parsing '$ls_command /' output"
 143
 144 # Get the extended ls output of the file or directory.
 145 set dummy x`eval "$ls_command \"\\\$save_arg1\""`
 146
 147 # Remove all preceding arguments
 148 eval $command
 149
 150 # Because of the dummy argument above, month is in $2.
 151 #
 152 # On a POSIX system, we should have
 153 #
 154 # $# = 5
 155 # $1 = file size
 156 # $2 = month
 157 # $3 = day
 158 # $4 = year or time
 159 # $5 = filename
 160 #
 161 # On Darwin 7.7.0 and 7.6.0, we have
 162 #
 163 # $# = 4
 164 # $1 = day
 165 # $2 = month
 166 # $3 = year or time
 167 # $4 = filename
 168
 169 # Get the month.
 170 case $2 in
 171   Jan) month=January; nummonth=1;;
 172   Feb) month=February; nummonth=2;;
 173   Mar) month=March; nummonth=3;;
 174   Apr) month=April; nummonth=4;;
 175   May) month=May; nummonth=5;;
 176   Jun) month=June; nummonth=6;;
 177   Jul) month=July; nummonth=7;;
 178   Aug) month=August; nummonth=8;;
 179   Sep) month=September; nummonth=9;;
 180   Oct) month=October; nummonth=10;;
 181   Nov) month=November; nummonth=11;;
 182   Dec) month=December; nummonth=12;;
 183 esac
 184
 185 case $3 in
 186   ???*) day=$1;;
 187   *) day=$3; shift;;
 188 esac
 189
 190 # Here we have to deal with the problem that the ls output gives either
 191 # the time of day or the year.
 192 case $3 in
 193   *:*) set `date`; eval year=\$$#
 194        case $2 in
 195          Jan) nummonthtod=1;;
 196          Feb) nummonthtod=2;;
 197          Mar) nummonthtod=3;;
 198          Apr) nummonthtod=4;;
 199          May) nummonthtod=5;;
 200          Jun) nummonthtod=6;;
 201          Jul) nummonthtod=7;;
 202          Aug) nummonthtod=8;;
 203          Sep) nummonthtod=9;;
 204          Oct) nummonthtod=10;;
 205          Nov) nummonthtod=11;;
 206          Dec) nummonthtod=12;;
 207        esac
 208        # For the first six month of the year the time notation can also
 209        # be used for files modified in the last year.
 210        if (expr $nummonth \> $nummonthtod) > /dev/null;
 211        then
 212          year=`expr $year - 1`
 213        fi;;
 214   *) year=$3;;
 215 esac
 216
 217 # The result.
 218 echo $day $month $year
 219
 220 # Local Variables:
 221 # mode: shell-script
 222 # sh-indentation: 2
 223 # eval: (add-hook 'write-file-hooks 'time-stamp)
 224 # time-stamp-start: "scriptversion="
 225 # time-stamp-format: "%:y-%02m-%02d.%02H"
 226 # time-stamp-time-zone: "UTC0"
 227 # time-stamp-end: "; # UTC"
 228 # End: