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1.1 otto 1: #!/bin/sh -
2: #
1.4 ! otto 3: # $OpenBSD: gzexe,v 1.3 2003/08/05 18:22:17 deraadt Exp $
1.1 otto 4: #
5: # Copyright (c) 2003 Otto Moerbeek <otto@drijf.net>
1.3 deraadt 6: #
1.1 otto 7: # Permission to use, copy, modify, and distribute this software for any
8: # purpose with or without fee is hereby granted, provided that the above
9: # copyright notice and this permission notice appear in all copies.
1.3 deraadt 10: #
1.1 otto 11: # THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12: # WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13: # MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14: # ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15: # WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16: # ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17: # OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18: #
19:
20: # The number of lines plus one in the on-the-fly decompression script
1.2 otto 21: lines=19
1.1 otto 22:
23: # A simple string to recognize already compressed files
24: magic="# compressed by gzexe"
25:
26: # Write the decompression script to stdout
27: header () {
28: typeset prog tmp
29: # first section needs variable expansion, second not
30: cat <<- EOF
31: #!/bin/sh -
32: $magic
33: lines=$lines
34: EOF
35: cat <<- 'EOF'
36: prog=`/usr/bin/basename "$0"`
37: tmp=`/usr/bin/mktemp -d /tmp/gzexeXXXXXXXXXX` || {
38: /bin/echo "$prog: cannot create tmp dir"; exit 1
39: }
40: trap '/bin/rm -rf "$tmp"' 0
1.2 otto 41: if /usr/bin/tail +$lines "$0" |
42: /usr/bin/gzip -dc > "$tmp/$prog" 2> /dev/null; then
1.1 otto 43: /bin/chmod u+x "$tmp/$prog"
44: "$tmp/$prog" ${1+"$@"}
45: ret=$?
46: else
47: /bin/echo "$prog: cannot decompress $0"
48: ret=1
49: fi
50: exit $ret
51: EOF
52: }
53:
54: # Test if a file is compressed by checking the magic line
55: compressed () {
56: test "X`sed -n 2p "$1" 2> /dev/null`" = "X$magic"
57: }
58:
59: # Decompress a file
60: decompress () {
61: tmp=`mktemp /tmp/gzexeXXXXXXXXXX` || {
62: echo "$prog: cannot create tmp file"
63: return 1
64: }
65: if ! cp "$1" "$tmp"; then
66: echo "$prog: cannot copy $1 to $tmp"
67: rm -f "$tmp"
68: return 1
69: fi
70: if ! tail +$lines "$tmp" | gzip -vdc > "$1"; then
71: echo "$prog: cannot decompress $1"
72: cp "$tmp" "$1"
73: rm -f "$tmp"
74: return 1
75: fi
76: }
77:
78: # Perform some sanity checks on the file
79: check () {
80: if test ! -e "$1"; then
81: echo "$prog: cannot compress non-existing file $1"
82: return 1
83: fi
84:
85: if test ! -f "$1"; then
86: echo "$prog: cannot compress non-regular file $1"
87: return 1
88: fi
89:
90: case `basename "$1"` in
1.4 ! otto 91: sh | mktemp | rm | echo | tail | gzip | chmod | basename)
1.1 otto 92: echo "$prog: cannot compress $1, I depend on it"
93: return 1
94: esac
95:
96: if test ! -x "$1"; then
97: echo "$prog: cannot compress $1, it is not executable"
98: return 1
99: fi
100:
101: if test -u "$1" -o -g "$1"; then
102: echo "$prog: cannot compress $1, it has an s bit set"
103: return 1
104: fi
1.4 ! otto 105:
! 106: # Build a list of files we should not compress.
! 107: # * files we need to decompress
! 108: CHECK_LIST="
! 109: /bin/chmod
! 110: /bin/echo
! 111: /bin/sh
! 112: /bin/rm
! 113: /usr/bin/basename
! 114: /usr/bin/gzip
! 115: /usr/bin/mktemp
! 116: /usr/bin/tail
! 117: "
! 118: # * files in /bin and /sbin (decompression fails if /usr/bin is not mounted)
! 119: # (You could skip these if /usr/bin is always mounted on the same mount point.)
! 120: CHECK_LIST="$CHECK_LIST
! 121: /bin/*
! 122: /sbin/*
! 123: "
! 124: # See if the program we are trying to compress is in the list.
! 125: # To avoid compressing hardlinked files (eg compress & gzip)
! 126: # we compare the device & inode.
! 127: PROG_STAT_INFO=`stat -f '%d %i' "$1"`
! 128: for CHECK in $CHECK_LIST; do
! 129: if test -f "$CHECK"; then
! 130: CHECK_STAT_INFO=`stat -f '%d %i' "$CHECK"`
! 131: if test "X$PROG_STAT_INFO" == "X$CHECK_STAT_INFO"; then
! 132: echo "$prog: cannot compress $1, it is the same file as $CHECK"
! 133: return 1
! 134: fi
! 135: fi
! 136: done
1.1 otto 137: }
138:
139: # Compress a file
140: compress () {
141: tmp=`mktemp /tmp/gzexeXXXXXXXXXX` || {
142: echo "$prog: cannot create tmp file"
143: return 1
144: }
145: if ! cp "$1" "$tmp"; then
146: echo "$prog: cannot copy $1 to $tmp"
147: rm -f "$tmp"
148: return 1
149: fi
150: if ! cp "$1" "$1"~; then
151: echo "$prog: cannot create backup copy $1~"
152: rm -f "$1"~ "$tmp"
153: return 1
154: fi
155:
156: # Use cp to overwrite the existing file preserving mode and owner
157: # if possible. If the file is not writable, this will produce an
158: # error.
159:
160: if header "$1" > "$tmp" && gzip -vc "$1" >> "$tmp"; then
161: if ! cp "$tmp" "$1"; then
162: echo "$prog: cannot copy $tmp to $1"
163: rm -f "$tmp"
164: return 1
165: fi
166: else
167: echo "$prog: cannot compress $1"
168: rm -f "$1"~ "$tmp"
169: return 1
170: fi
171: }
172:
173: # Is the -d flag specified?
174: dflag=
175:
176: # Return value
177: rc=0
178:
179: if test "X$1" = X-d; then
180: dflag=1
181: shift
182: fi
183:
184: prog=`basename "$0"`
185: USAGE="usage: $prog [-d] file ..."
186: if test $# -eq 0; then
187: echo $USAGE
188: exit 1
189: fi
190:
191: while test $# -ne 0; do
192: if test $dflag; then
193: if ! compressed "$1"; then
194: echo "$prog: $1 is not compressed"
195: rc=1;
196: elif ! decompress "$1"; then
197: rc=$?
198: fi
199: else
200: if compressed "$1"; then
201: echo "$prog: $1 is already compressed"
202: rc=1;
203: elif ! check "$1" || ! compress "$1"; then
204: rc=$?
205: fi
206: fi
207: shift
208: done
209: exit $rc