contrib/gdiffmk/gdiffmk.sh

   1 #!/bin/sh
   2 # This file is part of GNU gdiffmk.
   3 #
   4 # GNU gdiffmk is free software; you can redistribute it and/or modify it
   5 # under the terms of the GNU General Public License as published by the
   6 # Free Software Foundation; either version 2, or (at your option) any
   7 # later version.
   8 #
   9 # GNU gdiffmk is distributed in the hope that it will be useful, but
  10 # WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 # General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU General Public License
  15 # along with gdiffmk; see the file COPYING.  If not, write to the
  16 #    Free Software Foundation, Inc.
  17 #    59 Temple Place - Suite 330
  18 #    Boston, MA 02111-1307, USA.
  19
  20
  21 cmd=$( basename $0 )
  22
  23 diff -Dx /dev/null /dev/null >/dev/null 2>&1  ||
  24         {
  25                 echo >&2 "${cmd}:  "                            \
  26                         "The \`diff' program does not accept "  \
  27                         "the required -DNAME option."
  28                 echo >&2 "${cmd}:  "                            \
  29                         "Use GNU diff instead."
  30                 exit 126
  31         }
  32
  33 function Usage {
  34         if test "$#" -gt 0
  35         then
  36                 echo >&2 "${cmd}:  $@"
  37         fi
  38         echo >&2 "\
  39
  40 Usage:  ${cmd} [ OPTIONS ] FILE1 FILE2 [ OUTPUT ]
  41 Place difference marks into the new version of a groff/nroff/troff document.
  42 FILE1 and FILE2 are compared, using \`diff', and FILE2 is output with
  43 groff \`.mc' requests added to indicate how it is different from FILE1.
  44
  45   FILE1   Previous version of the groff file.  \`-' means standard input.
  46   FILE2   Current version of the groff file.  \`-' means standard input.
  47           Either FILE1 or FILE2 can be standard input, but not both.
  48   OUTPUT  Copy of FILE2 with \`.mc' commands added.
  49           \`-' means standard output (the default).
  50
  51 options:
  52   -a addmark     Mark for added groff source lines.    Default: +.
  53   -c changemark  Mark for changed groff source lines.  Default: |.
  54   -d deletemark  Mark for deleted groff source lines.  Default: *.
  55   --version      Print version information on standard output and exit.
  56   --help         Print this message on standard error.
  57 "
  58         exit 255
  59 }
  60
  61
  62 function Exit {
  63         exitcode=$1
  64         shift
  65         echo >&2 "${cmd}:  $@"
  66         exit ${exitcode}
  67 }
  68
  69 #       Usage:  FileRead  exit_code  filename
  70 #
  71 #       Check for existence and readability of given file name.
  72 #       If not found or not readable, print message and exit with EXIT_CODE.
  73 function FileRead {
  74         case "$2" in
  75         -)
  76                 return
  77                 ;;
  78         esac
  79
  80         if test ! -e "$2"
  81         then
  82                 Exit $1  "File \`$2' not found."
  83         fi
  84         if test ! -r "$2"
  85         then
  86                 Exit $1  "File \`$2' not readable."
  87         fi
  88 }
  89
  90
  91 #       Usage:  FileCreate  exit_code  filename
  92 #
  93 #       Create the given filename if it doesn't exist.
  94 #       If unable to create or write, print message and exit with EXIT_CODE.
  95 function FileCreate {
  96         case "$2" in
  97         -)
  98                 return
  99                 ;;
 100         esac
 101
 102         if ! touch "$2" 2>/dev/null
 103         then
 104                 if test ! -e "$2"
 105                 then
 106                         Exit $1 "File \`$2' not created; " \
 107                           "Cannot write directory \`$( dirname "$2" )'."
 108                 fi
 109                 Exit $1  "File \`$2' not writeable."
 110         fi
 111 }
 112
 113 function WouldClobber {
 114         case "$2" in
 115         -)
 116                 return
 117                 ;;
 118         esac
 119
 120         if test "$1" -ef "$3"
 121         then
 122                 Exit 3 "\`$3' is the same as \`$2' and would be clobbered."
 123         fi
 124 }
 125
 126 addmark='+'
 127 changemark='|'
 128 deletemark='*'
 129
 130 function RequiresArgument {
 131         #       Process flags that take either concatenated or
 132         #       separated values.
 133         case "$1" in
 134         -??*)
 135                 expr "$1" : '-.\(.*\)'
 136                 return 1
 137                 ;;
 138         esac
 139
 140         if test "$#" -lt 2
 141         then
 142                 Exit 255 "Option \`$1' requires a value."
 143         fi
 144
 145         echo "$2"
 146         return 0
 147 }
 148
 149 badoption=
 150 for option
 151 do
 152         case "${option}" in
 153         -a*)
 154                 addmark=$( RequiresArgument "${option}" $2 )            &&
 155                         shift
 156                 ;;
 157         -c*)
 158                 changemark=$( RequiresArgument "${option}" $2 )         &&
 159                         shift
 160                 ;;
 161         -d*)
 162                 deletemark=$( RequiresArgument "${option}" $2 )         &&
 163                         shift
 164                 ;;
 165         --version)
 166                 echo "GNU ${cmd} (groff) version @VERSION@"
 167                 exit 0
 168                 ;;
 169         --help)
 170                 Usage
 171                 ;;
 172         --)
 173                 #       What follows  --  are file arguments
 174                 shift
 175                 break
 176                 ;;
 177         -)
 178                 break
 179                 ;;
 180         -*)
 181                 badoption="${cmd}:  invalid option \`$1'"
 182                 ;;
 183         *)
 184                 break
 185                 ;;
 186         esac
 187         shift
 188 done
 189
 190 if test -n "${badoption}"
 191 then
 192         Usage "${badoption}"
 193 fi
 194
 195 if test "$#" -lt 2  -o  "$#" -gt 3
 196 then
 197         Usage "Incorrect number of arguments."
 198 fi
 199
 200 if test "1$1" = 1-  -a  "2$2" = 2-
 201 then
 202         Usage "Both FILE1 and FILE2 are \`-'."
 203 fi
 204
 205 FILE1=$1
 206 FILE2=$2
 207
 208 FileRead 1 "${FILE1}"
 209 FileRead 2 "${FILE2}"
 210
 211 if test "$#" = 3
 212 then
 213         case "$3" in
 214         -)
 215                 #       output goes to standard output
 216                 ;;
 217         *)
 218                 #       output goes to a file
 219                 WouldClobber "${FILE1}" FILE1 "$3"
 220                 WouldClobber "${FILE2}" FILE2 "$3"
 221
 222                 FileCreate 3 "$3"
 223                 exec >$3
 224                 ;;
 225         esac
 226 fi
 227
 228 #       To make a very unlikely label even more unlikely ...
 229 label=__diffmk_$$__
 230
 231 diff -D"${label}" -- ${FILE1} ${FILE2}  |
 232         sed -n '
 233                 /^#ifdef '"${label}"'/,/^#endif \/\* '"${label}"'/ {
 234                   /^#ifdef '"${label}"'/          s/.*/.mc '"${addmark}"'/
 235                   /^#endif \/\* '"${label}"'/     s/.*/.mc/
 236                   p
 237                   d
 238                 }
 239                 /^#ifndef '"${label}"'/,/^#endif \/\* [not ]*'"${label}"'/ {
 240                   /^#else \/\* '"${label}"'/,/^#endif \/\* '"${label}"'/ {
 241                     /^#else \/\* '"${label}"'/    s/.*/.mc '"${changemark}"'/
 242                     /^#endif \/\* '"${label}"'/   s/.*/.mc/
 243                     p
 244                     d
 245                   }
 246                   /^#endif \/\* not '"${label}"'/ s/.*/.mc '"${deletemark}"'/p
 247                   d
 248                 }
 249                 p
 250         '
 251
 252 # EOF