Annotation of src/usr.bin/compress/gzexe, Revision 1.3
1.1 otto 1: #!/bin/sh -
2: #
1.3 ! deraadt 3: # $OpenBSD: gzexe,v 1.2 2003/07/31 08:10:35 otto 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 "$1"` in
91: sh | mktemp | rm | echo | tail | gzip | chmod)
92: echo "$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 $1, it has an s bit set"
103: return 1
104: fi
105: }
106:
107: # Compress a file
108: compress () {
109: tmp=`mktemp /tmp/gzexeXXXXXXXXXX` || {
110: echo "$prog: cannot create tmp file"
111: return 1
112: }
113: if ! cp "$1" "$tmp"; then
114: echo "$prog: cannot copy $1 to $tmp"
115: rm -f "$tmp"
116: return 1
117: fi
118: if ! cp "$1" "$1"~; then
119: echo "$prog: cannot create backup copy $1~"
120: rm -f "$1"~ "$tmp"
121: return 1
122: fi
123:
124: # Use cp to overwrite the existing file preserving mode and owner
125: # if possible. If the file is not writable, this will produce an
126: # error.
127:
128: if header "$1" > "$tmp" && gzip -vc "$1" >> "$tmp"; then
129: if ! cp "$tmp" "$1"; then
130: echo "$prog: cannot copy $tmp to $1"
131: rm -f "$tmp"
132: return 1
133: fi
134: else
135: echo "$prog: cannot compress $1"
136: rm -f "$1"~ "$tmp"
137: return 1
138: fi
139: }
140:
141: # Is the -d flag specified?
142: dflag=
143:
144: # Return value
145: rc=0
146:
147: if test "X$1" = X-d; then
148: dflag=1
149: shift
150: fi
151:
152: prog=`basename "$0"`
153: USAGE="usage: $prog [-d] file ..."
154: if test $# -eq 0; then
155: echo $USAGE
156: exit 1
157: fi
158:
159: while test $# -ne 0; do
160: if test $dflag; then
161: if ! compressed "$1"; then
162: echo "$prog: $1 is not compressed"
163: rc=1;
164: elif ! decompress "$1"; then
165: rc=$?
166: fi
167: else
168: if compressed "$1"; then
169: echo "$prog: $1 is already compressed"
170: rc=1;
171: elif ! check "$1" || ! compress "$1"; then
172: rc=$?
173: fi
174: fi
175: shift
176: done
177: exit $rc