bzexe

   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 $skip lines of shell commands.  We try invoking the compressed
   7 # executable with the original name (for programs looking at their name).
   8 # We also try to retain the original file permissions on the compressed file.
   9 # For safety reasons, gzexe will not create setuid or setgid shell scripts.
  10
  11 # WARNING: the first line of this file must be either : or #!/bin/sh
  12 # The : is required for some old versions of csh.
  13 # On Ultrix, /bin/sh is too buggy, change the first line to: #!/bin/sh5
  14
  15
  16 # Copyright (C) 1998, 2002 Free Software Foundation
  17 # Copyright (C) 1993 Jean-loup Gailly
  18
  19 # This program is free software; you can redistribute it and/or modify
  20 # it under the terms of the GNU General Public License as published by
  21 # the Free Software Foundation; either version 2, or (at your option)
  22 # any later version.
  23
  24 # This program is distributed in the hope that it will be useful,
  25 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  26 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  27 # GNU General Public License for more details.
  28
  29 # You should have received a copy of the GNU General Public License
  30 # along with this program; if not, write to the Free Software
  31 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  32 # 02111-1307, USA.
  33
  34
  35 PATH="/usr/bin:$PATH"
  36 x=`basename $0`
  37 if test $# = 0; then
  38   echo compress executables. original file foo is renamed to foo~
  39   echo usage: ${x} [-d] files...
  40   echo   "   -d  decompress the executables"
  41   exit 1
  42 fi
  43
  44 set -C
  45 tmp=gz$$
  46 trap "rm -f $tmp; exit 1" HUP INT QUIT TRAP USR1 PIPE TERM
  47 : > $tmp || exit 1
  48
  49 decomp=0
  50 res=0
  51 test "$x" = "ungzexe" && decomp=1
  52 if test "x$1" = "x-d"; then
  53   decomp=1
  54   shift
  55 fi
  56
  57 echo hi > zfoo1$$ || exit 1
  58 echo hi > zfoo2$$ || exit 1
  59 if test -z "`(${CPMOD-cpmod} zfoo1$$ zfoo2$$) 2>&1`"; then
  60   cpmod=${CPMOD-cpmod}
  61 fi
  62 rm -f zfoo[12]$$
  63
  64 tail=""
  65 IFS="${IFS=     }"; saveifs="$IFS"; IFS="${IFS}:"
  66 for dir in $PATH; do
  67   test -z "$dir" && dir=.
  68   if test -f $dir/tail; then
  69     tail="$dir/tail"
  70     break
  71   fi
  72 done
  73 IFS="$saveifs"
  74 if test -z "$tail"; then
  75   echo cannot find tail
  76   exit 1
  77 fi
  78 case `echo foo | $tail -n +1 2>/dev/null` in
  79 foo) tail="$tail -n";;
  80 esac
  81
  82 for i do
  83   if test ! -f "$i" ; then
  84     echo ${x}: $i not a file
  85     res=1
  86     continue
  87   fi
  88   if test $decomp -eq 0; then
  89     if sed -e 1d -e 2q "$i" | grep "^skip=[0-9]*$" >/dev/null; then
  90       echo "${x}: $i is already gzexe'd"
  91       continue
  92     fi
  93   fi
  94   if ls -l "$i" | grep '^...[sS]' > /dev/null; then
  95     echo "${x}: $i has setuid permission, unchanged"
  96     continue
  97   fi
  98   if ls -l "$i" | grep '^......[sS]' > /dev/null; then
  99     echo "${x}: $i has setgid permission, unchanged"
 100     continue
 101   fi
 102   case "`basename $i`" in
 103   bzip2 | tail | sed | chmod | ln | sleep | rm)
 104         echo "${x}: $i would depend on itself"; continue ;;
 105   esac
 106   if test -z "$cpmod"; then
 107     cp -p "$i" $tmp 2>/dev/null || cp "$i" $tmp
 108     if test -w $tmp 2>/dev/null; then
 109       writable=1
 110     else
 111       writable=0
 112       chmod u+w $tmp 2>/dev/null
 113     fi
 114     : >| $tmp  # truncate the file, ignoring set -C
 115   fi
 116   if test $decomp -eq 0; then
 117     sed 1q $0 >> $tmp
 118     sed "s|^if tail|if $tail|" >> $tmp <<'EOF'
 119 skip=23
 120 set -C
 121 umask=`umask`
 122 umask 77
 123 tmpfile=`tempfile -p gztmp -d /tmp` || exit 1
 124 if tail +$skip "$0" | /bin/bzip2 -cd >> $tmpfile; then
 125   umask $umask
 126   /bin/chmod 700 $tmpfile
 127   prog="`echo $0 | /bin/sed 's|^.*/||'`"
 128   if /bin/ln $tmpfile "/tmp/$prog" 2>/dev/null; then
 129     trap '/bin/rm -f $tmpfile "/tmp/$prog"; exit $res' 0
 130     (/bin/sleep 5; /bin/rm -f $tmpfile "/tmp/$prog") 2>/dev/null &
 131     /tmp/"$prog" ${1+"$@"}; res=$?
 132   else
 133     trap '/bin/rm -f $tmpfile; exit $res' 0
 134     (/bin/sleep 5; /bin/rm -f $tmpfile) 2>/dev/null &
 135     $tmpfile ${1+"$@"}; res=$?
 136   fi
 137 else
 138   echo Cannot decompress $0; exit 1
 139 fi; exit $res
 140 EOF
 141     bzip2 -cv9 "$i" >> $tmp || {
 142       /bin/rm -f $tmp
 143       echo ${x}: compression not possible for $i, file unchanged.
 144       res=1
 145       continue
 146     }
 147
 148   else
 149     # decompression
 150     skip=23
 151     if sed -e 1d -e 2q "$i" | grep "^skip=[0-9]*$" >/dev/null; then
 152       eval `sed -e 1d -e 2q "$i"`
 153     fi
 154     if tail +$skip "$i" | bzip2 -cd > $tmp; then
 155       :
 156     else
 157       echo ${x}: $i probably not in gzexe format, file unchanged.
 158       res=1
 159       continue
 160     fi
 161   fi
 162   rm -f "$i~"
 163   mv "$i" "$i~" || {
 164     echo ${x}: cannot backup $i as $i~
 165     rm -f $tmp
 166     res=1
 167     continue
 168   }
 169   mv $tmp "$i" || cp -p $tmp "$i" 2>/dev/null || cp $tmp "$i" || {
 170     echo ${x}: cannot create $i
 171     rm -f $tmp
 172     res=1
 173     continue
 174   }
 175   rm -f $tmp
 176   if test -n "$cpmod"; then
 177     $cpmod "$i~" "$i" 2>/dev/null
 178   elif test $writable -eq 0; then
 179     chmod u-w $i 2>/dev/null
 180   fi
 181 done
 182 exit $res