gzexe.in

   1 #!/bin/sh
   2 # gzexe: compressor for Unix executables.
   3 # Use this only for binaries that you do not use frequently.
   4 #
   5 # The compressed version is a shell script which decompresses itself after
   6 # skipping $skip lines of shell commands.  We try invoking the compressed
   7 # executable with the original name (for programs looking at their name).
   8 # We also try to retain the original file permissions on the compressed file.
   9 # For safety reasons, gzexe will not create setuid or setgid shell scripts.
  10
  11 # WARNING: the first line of this file must be either : or #!/bin/sh
  12 # The : is required for some old versions of csh.
  13 # On Ultrix, /bin/sh is too buggy, change the first line to: #!/bin/sh5
  14
  15
  16 # Copyright (C) 1998, 2002, 2004, 2006-2007, 2010-2024 Free Software
  17 # Foundation, Inc.
  18 # Copyright (C) 1993 Jean-loup Gailly
  19
  20 # This program is free software; you can redistribute it and/or modify
  21 # it under the terms of the GNU General Public License as published by
  22 # the Free Software Foundation; either version 3 of the License, or
  23 # (at your option) any later version.
  24
  25 # This program is distributed in the hope that it will be useful,
  26 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  27 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  28 # GNU General Public License for more details.
  29
  30 # You should have received a copy of the GNU General Public License along
  31 # with this program; if not, write to the Free Software Foundation, Inc.,
  32 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  33
  34 tab='   '
  35 nl='
  36 '
  37 IFS=" $tab$nl"
  38
  39 version='gzexe (gzip) @VERSION@
  40 Copyright (C) 2024 Free Software Foundation, Inc.
  41 This is free software.  You may redistribute copies of it under the terms of
  42 the GNU General Public License <https://www.gnu.org/licenses/gpl.html>.
  43 There is NO WARRANTY, to the extent permitted by law.
  44
  45 Written by Jean-loup Gailly.'
  46
  47 usage="Usage: $0 [OPTION] FILE...
  48 Replace each executable FILE with a compressed version of itself.
  49 Make a backup FILE~ of the old version of FILE.
  50
  51   -d             Decompress each FILE instead of compressing it.
  52       --help     display this help and exit
  53       --version  output version information and exit
  54
  55 Report bugs to <bug-gzip@gnu.org>."
  56
  57 decomp=0
  58 res=0
  59 while :; do
  60   case $1 in
  61   -d) decomp=1; shift;;
  62   --h*) printf '%s\n' "$usage"   || exit 1; exit;;
  63   --v*) printf '%s\n' "$version" || exit 1; exit;;
  64   --) shift; break;;
  65   *) break;;
  66   esac
  67 done
  68
  69 if test $# -eq 0; then
  70   printf >&2 '%s\n' "$0: missing operand
  71 Try \`$0 --help' for more information."
  72   exit 1
  73 fi
  74
  75 tmp=
  76 trap 'res=$?
  77   test -n "$tmp" && rm -f "$tmp"
  78   (exit $res); exit $res
  79 ' 0 1 2 3 5 10 13 15
  80
  81 mktemp_status=
  82
  83 for i do
  84   case $i in
  85   -*) file=./$i;;
  86   *)  file=$i;;
  87   esac
  88   if test ! -f "$file" || test ! -r "$file"; then
  89     res=$?
  90     printf >&2 '%s\n' "$0: $i is not a readable regular file"
  91     continue
  92   fi
  93   if test $decomp -eq 0; then
  94     case `LC_ALL=C sed -n -e 1d -e '/^skip=[0-9][0-9]*$/p' -e 2q "$file"` in
  95     skip=[0-9] | skip=[0-9][0-9] | skip=[0-9][0-9][0-9])
  96       printf >&2 '%s\n' "$0: $i is already gzexe'd"
  97       continue;;
  98     esac
  99   fi
 100   if test -u "$file"; then
 101     printf >&2 '%s\n' "$0: $i has setuid permission, unchanged"
 102     continue
 103   fi
 104   if test -g "$file"; then
 105     printf >&2 '%s\n' "$0: $i has setgid permission, unchanged"
 106     continue
 107   fi
 108   case /$file in
 109   */basename | */bash | */cat | */chmod | */cp | \
 110   */dirname | */expr | */'gzip' | \
 111   */ln | */mkdir | */mktemp | */mv | */printf | */rm | \
 112   */sed | */sh | */sleep | */test | */tail)
 113     printf >&2 '%s\n' "$0: $i might depend on itself"; continue;;
 114   esac
 115
 116   dir=`dirname "$file"` || dir=$TMPDIR
 117   test -d "$dir" && test -w "$dir" && test -x "$dir" || dir=/tmp
 118   test -n "$tmp" && rm -f "$tmp"
 119   if test -z "$mktemp_status"; then
 120     type mktemp >/dev/null 2>&1
 121     mktemp_status=$?
 122   fi
 123   case $dir in
 124     */) ;;
 125     *) dir=$dir/;;
 126   esac
 127   if test $mktemp_status -eq 0; then
 128     tmp=`mktemp "${dir}gzexeXXXXXXXXX"`
 129   else
 130     tmp=${dir}gzexe$$
 131   fi && { cp -p "$file" "$tmp" 2>/dev/null || cp "$file" "$tmp"; } || {
 132     res=$?
 133     printf >&2 '%s\n' "$0: cannot copy $file"
 134     continue
 135   }
 136   if test -w "$tmp"; then
 137     writable=1
 138   else
 139     writable=0
 140     chmod u+w "$tmp" || {
 141       res=$?
 142       printf >&2 '%s\n' "$0: cannot chmod $tmp"
 143       continue
 144     }
 145   fi
 146   if test $decomp -eq 0; then
 147     (cat <<'EOF' &&
 148 #!/bin/sh
 149 skip=49
 150
 151 tab='   '
 152 nl='
 153 '
 154 IFS=" $tab$nl"
 155
 156 umask=`umask`
 157 umask 77
 158
 159 gztmpdir=
 160 trap 'res=$?
 161   test -n "$gztmpdir" && rm -fr "$gztmpdir"
 162   (exit $res); exit $res
 163 ' 0 1 2 3 5 10 13 15
 164
 165 case $TMPDIR in
 166   / | /*/) ;;
 167   /*) TMPDIR=$TMPDIR/;;
 168   *) TMPDIR=/tmp/;;
 169 esac
 170 if type mktemp >/dev/null 2>&1; then
 171   gztmpdir=`mktemp -d "${TMPDIR}gztmpXXXXXXXXX"`
 172 else
 173   gztmpdir=${TMPDIR}gztmp$$; mkdir $gztmpdir
 174 fi || { (exit 127); exit 127; }
 175
 176 gztmp=$gztmpdir/$0
 177 case $0 in
 178 -* | */*'
 179 ') mkdir -p "$gztmp" && rm -r "$gztmp";;
 180 */*) gztmp=$gztmpdir/`basename "$0"`;;
 181 esac || { (exit 127); exit 127; }
 182
 183 case `printf 'X\n' | tail -n +1 2>/dev/null` in
 184 X) tail_n=-n;;
 185 *) tail_n=;;
 186 esac
 187 if tail $tail_n +$skip <"$0" | 'gzip' -cd > "$gztmp"; then
 188   umask $umask
 189   chmod 700 "$gztmp"
 190   (sleep 5; rm -fr "$gztmpdir") 2>/dev/null &
 191   "$gztmp" ${1+"$@"}; res=$?
 192 else
 193   printf >&2 '%s\n' "Cannot decompress $0"
 194   (exit 127); res=127
 195 fi; exit $res
 196 EOF
 197     'gzip' -cv9 "$file") > "$tmp" || {
 198       res=$?
 199       printf >&2 '%s\n' "$0: compression not possible for $i, file unchanged."
 200       continue
 201     }
 202
 203   else
 204     # decompression
 205     skip=44
 206     skip_line=`LC_ALL=C sed -e 1d -e 2q "$file"`
 207     case $skip_line in
 208     skip=[0-9] | skip=[0-9][0-9] | skip=[0-9][0-9][0-9])
 209       eval "$skip_line";;
 210     esac
 211     case `printf 'X\n' | tail -n +1 2>/dev/null` in
 212     X) tail_n=-n;;
 213     *) tail_n=;;
 214     esac
 215     tail $tail_n +$skip "$file" | 'gzip' -cd > "$tmp" || {
 216       res=$?
 217       printf >&2 '%s\n' "$0: $i probably not in gzexe format, file unchanged."
 218       continue
 219     }
 220   fi
 221   test $writable -eq 1 || chmod u-w "$tmp" || {
 222     res=$?
 223     printf >&2 '%s\n' "$0: $tmp: cannot chmod"
 224     continue
 225   }
 226   ln -f "$file" "$file~" 2>/dev/null || {
 227     # Hard links may not work.  Fall back on rm+cp so that $file always exists.
 228     rm -f "$file~" && cp -p "$file" "$file~"
 229   } || {
 230     res=$?
 231     printf >&2 '%s\n' "$0: cannot backup $i as $i~"
 232     continue
 233   }
 234   mv -f "$tmp" "$file" || {
 235     res=$?
 236     printf >&2 '%s\n' "$0: cannot rename $tmp to $i"
 237     continue
 238   }
 239   tmp=
 240 done
 241 (exit $res); exit $res