compress.c revision 116336 
1/*-
2 * Copyright (c) 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 *    must display the following acknowledgement:
15 *	This product includes software developed by the University of
16 *	California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35static const char copyright[] =
36"@(#) Copyright (c) 1992, 1993\n\
37	The Regents of the University of California.  All rights reserved.\n";
38#endif
39
40#if 0
41#ifndef lint
42static char sccsid[] = "@(#)compress.c	8.2 (Berkeley) 1/7/94";
43#endif
44#endif
45
46#include <sys/cdefs.h>
47__FBSDID("$FreeBSD: head/usr.bin/compress/compress.c 116336 2003-06-14 13:41:31Z trhodes $");
48
49#include <sys/param.h>
50#include <sys/stat.h>
51#include <sys/time.h>
52
53#include <err.h>
54#include <errno.h>
55#include <stdarg.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <unistd.h>
60
61#include "zopen.h"
62
63void	compress(const char *, const char *, int);
64void	cwarn(const char *, ...) __printflike(1, 2);
65void	cwarnx(const char *, ...) __printflike(1, 2);
66void	decompress(const char *, const char *, int);
67int	permission(const char *);
68void	setfile(const char *, struct stat *);
69void	usage(int);
70
71int eval, force, verbose;
72
73int
74main(int argc, char *argv[])
75{
76	enum {COMPRESS, DECOMPRESS} style;
77	size_t len;
78	int bits, cat, ch;
79	char *p, newname[MAXPATHLEN];
80
81	cat = 0;
82	if ((p = rindex(argv[0], '/')) == NULL)
83		p = argv[0];
84	else
85		++p;
86	if (!strcmp(p, "uncompress"))
87		style = DECOMPRESS;
88	else if (!strcmp(p, "compress"))
89		style = COMPRESS;
90	else if (!strcmp(p, "zcat")) {
91		cat = 1;
92		style = DECOMPRESS;
93	} else
94		errx(1, "unknown program name");
95
96	bits = 0;
97	while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
98		switch(ch) {
99		case 'b':
100			bits = strtol(optarg, &p, 10);
101			if (*p)
102				errx(1, "illegal bit count -- %s", optarg);
103			break;
104		case 'c':
105			cat = 1;
106			break;
107		case 'd':		/* Backward compatible. */
108			style = DECOMPRESS;
109			break;
110		case 'f':
111			force = 1;
112			break;
113		case 'v':
114			verbose = 1;
115			break;
116		case '?':
117		default:
118			usage(style == COMPRESS);
119		}
120	argc -= optind;
121	argv += optind;
122
123	if (argc == 0) {
124		switch(style) {
125		case COMPRESS:
126			(void)compress("/dev/stdin", "/dev/stdout", bits);
127			break;
128		case DECOMPRESS:
129			(void)decompress("/dev/stdin", "/dev/stdout", bits);
130			break;
131		}
132		exit (eval);
133	}
134
135	if (cat == 1 && argc > 1)
136		errx(1, "the -c option permits only a single file argument");
137
138	for (; *argv; ++argv)
139		switch(style) {
140		case COMPRESS:
141			if (strcmp(*argv, "-") == 0) {
142				compress("/dev/stdin", "/dev/stdout", bits);
143				break;
144			} else if (cat) {
145				compress(*argv, "/dev/stdout", bits);
146				break;
147			}
148			if ((p = rindex(*argv, '.')) != NULL &&
149			    !strcmp(p, ".Z")) {
150				cwarnx("%s: name already has trailing .Z",
151				    *argv);
152				break;
153			}
154			len = strlen(*argv);
155			if (len > sizeof(newname) - 3) {
156				cwarnx("%s: name too long", *argv);
157				break;
158			}
159			memmove(newname, *argv, len);
160			newname[len] = '.';
161			newname[len + 1] = 'Z';
162			newname[len + 2] = '\0';
163			compress(*argv, newname, bits);
164			break;
165		case DECOMPRESS:
166			if (strcmp(*argv, "-") == 0) {
167				decompress("/dev/stdin", "/dev/stdout", bits);
168				break;
169			}
170			len = strlen(*argv);
171			if ((p = rindex(*argv, '.')) == NULL ||
172			    strcmp(p, ".Z")) {
173				if (len > sizeof(newname) - 3) {
174					cwarnx("%s: name too long", *argv);
175					break;
176				}
177				memmove(newname, *argv, len);
178				newname[len] = '.';
179				newname[len + 1] = 'Z';
180				newname[len + 2] = '\0';
181				decompress(newname,
182				    cat ? "/dev/stdout" : *argv, bits);
183			} else {
184				if (len - 2 > sizeof(newname) - 1) {
185					cwarnx("%s: name too long", *argv);
186					break;
187				}
188				memmove(newname, *argv, len - 2);
189				newname[len - 2] = '\0';
190				decompress(*argv,
191				    cat ? "/dev/stdout" : newname, bits);
192			}
193			break;
194		}
195	exit (eval);
196}
197
198void
199compress(const char *in, const char *out, int bits)
200{
201	size_t nr;
202	struct stat isb, sb;
203	FILE *ifp, *ofp;
204	int exists, isreg, oreg;
205	u_char buf[1024];
206
207	exists = !stat(out, &sb);
208	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
209		return;
210	isreg = oreg = !exists || S_ISREG(sb.st_mode);
211
212	ifp = ofp = NULL;
213	if ((ifp = fopen(in, "r")) == NULL) {
214		cwarn("%s", in);
215		return;
216	}
217	if (stat(in, &isb)) {		/* DON'T FSTAT! */
218		cwarn("%s", in);
219		goto err;
220	}
221	if (!S_ISREG(isb.st_mode))
222		isreg = 0;
223
224	if ((ofp = zopen(out, "w", bits)) == NULL) {
225		cwarn("%s", out);
226		goto err;
227	}
228	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
229		if (fwrite(buf, 1, nr, ofp) != nr) {
230			cwarn("%s", out);
231			goto err;
232		}
233
234	if (ferror(ifp) || fclose(ifp)) {
235		cwarn("%s", in);
236		goto err;
237	}
238	ifp = NULL;
239
240	if (fclose(ofp)) {
241		cwarn("%s", out);
242		goto err;
243	}
244	ofp = NULL;
245
246	if (isreg) {
247		if (stat(out, &sb)) {
248			cwarn("%s", out);
249			goto err;
250		}
251
252		if (!force && sb.st_size >= isb.st_size) {
253			if (verbose)
254		(void)fprintf(stderr, "%s: file would grow; left unmodified\n",
255		    in);
256			eval = 2;
257			if (unlink(out))
258				cwarn("%s", out);
259			goto err;
260		}
261
262		setfile(out, &isb);
263
264		if (unlink(in))
265			cwarn("%s", in);
266
267		if (verbose) {
268			(void)fprintf(stderr, "%s: ", out);
269			if (isb.st_size > sb.st_size)
270				(void)fprintf(stderr, "%.0f%% compression\n",
271				    ((float)sb.st_size / isb.st_size) * 100.0);
272			else
273				(void)fprintf(stderr, "%.0f%% expansion\n",
274				    ((float)isb.st_size / sb.st_size) * 100.0);
275		}
276	}
277	return;
278
279err:	if (ofp) {
280		if (oreg)
281			(void)unlink(out);
282		(void)fclose(ofp);
283	}
284	if (ifp)
285		(void)fclose(ifp);
286}
287
288void
289decompress(const char *in, const char *out, int bits)
290{
291	size_t nr;
292	struct stat sb;
293	FILE *ifp, *ofp;
294	int exists, isreg, oreg;
295	u_char buf[1024];
296
297	exists = !stat(out, &sb);
298	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
299		return;
300	isreg = oreg = !exists || S_ISREG(sb.st_mode);
301
302	ifp = ofp = NULL;
303	if ((ifp = zopen(in, "r", bits)) == NULL) {
304		cwarn("%s", in);
305		return;
306	}
307	if (stat(in, &sb)) {
308		cwarn("%s", in);
309		goto err;
310	}
311	if (!S_ISREG(sb.st_mode))
312		isreg = 0;
313
314	/*
315	 * Try to read the first few uncompressed bytes from the input file
316	 * before blindly truncating the output file.
317	 */
318	if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
319		cwarn("%s", in);
320		(void)fclose(ifp);
321		return;
322	}
323	if ((ofp = fopen(out, "w")) == NULL ||
324	    (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
325		cwarn("%s", out);
326		(void)fclose(ifp);
327		return;
328	}
329
330	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
331		if (fwrite(buf, 1, nr, ofp) != nr) {
332			cwarn("%s", out);
333			goto err;
334		}
335
336	if (ferror(ifp) || fclose(ifp)) {
337		cwarn("%s", in);
338		goto err;
339	}
340	ifp = NULL;
341
342	if (fclose(ofp)) {
343		cwarn("%s", out);
344		goto err;
345	}
346
347	if (isreg) {
348		setfile(out, &sb);
349
350		if (unlink(in))
351			cwarn("%s", in);
352	}
353	return;
354
355err:	if (ofp) {
356		if (oreg)
357			(void)unlink(out);
358		(void)fclose(ofp);
359	}
360	if (ifp)
361		(void)fclose(ifp);
362}
363
364void
365setfile(const char *name, struct stat *fs)
366{
367	static struct timeval tv[2];
368
369	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
370
371	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
372	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
373	if (utimes(name, tv))
374		cwarn("utimes: %s", name);
375
376	/*
377	 * Changing the ownership probably won't succeed, unless we're root
378	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
379	 * the mode; current BSD behavior is to remove all setuid bits on
380	 * chown.  If chown fails, lose setuid/setgid bits.
381	 */
382	if (chown(name, fs->st_uid, fs->st_gid)) {
383		if (errno != EPERM)
384			cwarn("chown: %s", name);
385		fs->st_mode &= ~(S_ISUID|S_ISGID);
386	}
387	if (chmod(name, fs->st_mode) && errno != EOPNOTSUPP)
388		cwarn("chmod: %s", name);
389
390	if (chflags(name, fs->st_flags) && errno != EOPNOTSUPP)
391		cwarn("chflags: %s", name);
392}
393
394int
395permission(const char *fname)
396{
397	int ch, first;
398
399	if (!isatty(fileno(stderr)))
400		return (0);
401	(void)fprintf(stderr, "overwrite %s? ", fname);
402	first = ch = getchar();
403	while (ch != '\n' && ch != EOF)
404		ch = getchar();
405	return (first == 'y');
406}
407
408void
409usage(int iscompress)
410{
411	if (iscompress)
412		(void)fprintf(stderr,
413		    "usage: compress [-cfv] [-b bits] [file ...]\n");
414	else
415		(void)fprintf(stderr,
416		    "usage: uncompress [-c] [-b bits] [file ...]\n");
417	exit(1);
418}
419
420void
421cwarnx(const char *fmt, ...)
422{
423	va_list ap;
424
425	va_start(ap, fmt);
426	vwarnx(fmt, ap);
427	va_end(ap);
428	eval = 1;
429}
430
431void
432cwarn(const char *fmt, ...)
433{
434	va_list ap;
435
436	va_start(ap, fmt);
437	vwarn(fmt, ap);
438	va_end(ap);
439	eval = 1;
440}
441