gzexe.in

来自「采用 LZ77 运算规则 压缩及解压工具」· IN 代码 · 共 55 行

:
#!/bin/sh
# Compressor for Unix executables.
# Use this only for binaries that you do not use frequently.
# The compressed version is a shell script which decompresses itself
# after skipping 18 lines of shell commands.

if test $# = 0; then
  echo compress executables. original file foo is renamed to foo~
  echo usage: `basename $0` files...
  exit 1
fi

res=0
for i do
  if test ! -f $i ; then
    echo `basename $0`: $i not found
    res=1
    continue
  fi

# Try invoking the compressed executable with the original name:
  sed "s,foo,$i," > g$$ <<'EOF'
#!/bin/sh
if tail +18 $0 | gzip -cd > /tmp/gztmp$$; then
  chmod 755 /tmp/gztmp$$
  if ln /tmp/gztmp$$ /tmp/foo 2>/dev/null; then
    /tmp/foo $*
    res=$?
    /bin/rm -f /tmp/gztmp$$ /tmp/foo
  else
    /tmp/gztmp$$ $*
    res=$?
    /bin/rm -f /tmp/gztmp$$
  fi
else
  echo Cannot decompress $0
  exit 1
fi
exit $res
EOF

  if gzip -cv9 $i >> g$$; then
    /bin/rm -f $i~
    mv $i $i~
    mv g$$ $i
    chmod 755 $i
  else
    /bin/rm -f g$$
    echo `basename $0`: compression not possible for $i, file unchanged.
    res=1
  fi
done
exit $res