1/*	$NetBSD: compress.c,v 1.25 2009/04/11 12:24:37 lukem Exp $	*/
2
3/*-
4 * Copyright (c) 1992, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <sys/cdefs.h>
33#ifndef lint
34__COPYRIGHT("@(#) Copyright (c) 1992, 1993\
35 The Regents of the University of California.  All rights reserved.");
36#endif /* not lint */
37
38#ifndef lint
39#if 0
40static char sccsid[] = "@(#)compress.c	8.2 (Berkeley) 1/7/94";
41#else
42__RCSID("$NetBSD: compress.c,v 1.25 2009/04/11 12:24:37 lukem Exp $");
43#endif
44#endif /* not lint */
45
46#include <sys/param.h>
47#include <sys/time.h>
48#include <sys/stat.h>
49
50#include <err.h>
51#include <errno.h>
52#include <stdarg.h>
53#include <stdio.h>
54#include <stdlib.h>
55#include <string.h>
56#include <unistd.h>
57
58static void	compress(const char *, const char *, int);
59static void	cwarn(const char *, ...) __printflike(1, 2);
60static void	cwarnx(const char *, ...) __printflike(1, 2);
61static void	decompress(const char *, const char *, int);
62static int	permission(const char *);
63static void	setfile(const char *, struct stat *);
64__dead static void	usage(int);
65
66extern FILE *zopen(const char *fname, const char *mode, int bits);
67
68static int eval, force, verbose;
69static int isstdout, isstdin;
70
71int
72main(int argc, char **argv)
73{
74        enum {COMPRESS, DECOMPRESS} style = COMPRESS;
75	size_t len;
76	int bits, cat, ch;
77	char *p, newname[MAXPATHLEN];
78
79	if ((p = strrchr(argv[0], '/')) == NULL)
80		p = argv[0];
81	else
82		++p;
83	if (!strcmp(p, "uncompress"))
84		style = DECOMPRESS;
85        else if (!strcmp(p, "compress"))
86                style = COMPRESS;
87        else if (!strcmp(p, "zcat")) {
88                style = DECOMPRESS;
89                cat = 1;
90        }
91	else
92		errx(1, "unknown program name");
93
94	bits = cat = 0;
95	while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
96		switch(ch) {
97		case 'b':
98			bits = strtol(optarg, &p, 10);
99			if (*p)
100				errx(1, "illegal bit count -- %s", optarg);
101			break;
102		case 'c':
103			cat = 1;
104			break;
105		case 'd':		/* Backward compatible. */
106			style = DECOMPRESS;
107			break;
108		case 'f':
109			force = 1;
110			break;
111		case 'v':
112			verbose = 1;
113			break;
114		case '?':
115		default:
116			usage(style == COMPRESS);
117		}
118	argc -= optind;
119	argv += optind;
120
121	if (argc == 0) {
122		switch(style) {
123		case COMPRESS:
124			isstdout = 1;
125			isstdin = 1;
126			(void)compress("/dev/stdin", "/dev/stdout", bits);
127			break;
128		case DECOMPRESS:
129			isstdout = 1;
130			isstdin = 1;
131			(void)decompress("/dev/stdin", "/dev/stdout", bits);
132			break;
133		}
134		exit (eval);
135	}
136
137	if (cat == 1 && argc > 1)
138		errx(1, "the -c option permits only a single file argument");
139
140	for (; *argv; ++argv) {
141		isstdout = 0;
142		switch(style) {
143		case COMPRESS:
144			if (cat) {
145				isstdout = 1;
146				compress(*argv, "/dev/stdout", bits);
147				break;
148			}
149			if ((p = strrchr(*argv, '.')) != NULL &&
150			    !strcmp(p, ".Z")) {
151				cwarnx("%s: name already has trailing .Z",
152				    *argv);
153				break;
154			}
155			len = strlen(*argv);
156			if (len > sizeof(newname) - 3) {
157				cwarnx("%s: name too long", *argv);
158				break;
159			}
160			memmove(newname, *argv, len);
161			newname[len] = '.';
162			newname[len + 1] = 'Z';
163			newname[len + 2] = '\0';
164			compress(*argv, newname, bits);
165			break;
166		case DECOMPRESS:
167			len = strlen(*argv);
168			if ((p = strrchr(*argv, '.')) == NULL ||
169			    strcmp(p, ".Z")) {
170				if (len > sizeof(newname) - 3) {
171					cwarnx("%s: name too long", *argv);
172					break;
173				}
174				memmove(newname, *argv, len);
175				newname[len] = '.';
176				newname[len + 1] = 'Z';
177				newname[len + 2] = '\0';
178				decompress(newname,
179				    cat ? "/dev/stdout" : *argv, bits);
180				if (cat)
181					isstdout = 1;
182			} else {
183				if (len - 2 > sizeof(newname) - 1) {
184					cwarnx("%s: name too long", *argv);
185					break;
186				}
187				memmove(newname, *argv, len - 2);
188				newname[len - 2] = '\0';
189				decompress(*argv,
190				    cat ? "/dev/stdout" : newname, bits);
191				if (cat)
192					isstdout = 1;
193			}
194			break;
195		}
196	}
197	exit (eval);
198}
199
200static void
201compress(const char *in, const char *out, int bits)
202{
203	size_t nr;
204	struct stat isb, sb;
205	const char *error = NULL;
206	FILE *ifp, *ofp;
207	int exists, isreg, oreg;
208	u_char buf[BUFSIZ];
209
210	if (!isstdout) {
211		exists = !stat(out, &sb);
212		if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
213			return;
214		oreg = !exists || S_ISREG(sb.st_mode);
215	} else
216		oreg = 0;
217
218	ifp = ofp = NULL;
219	if ((ifp = fopen(in, "r")) == NULL) {
220		cwarn("%s", in);
221		return;
222	}
223
224	if (!isstdin) {
225		if (stat(in, &isb)) {		/* DON'T FSTAT! */
226			cwarn("%s", in);
227			goto err;
228		}
229		if (!S_ISREG(isb.st_mode))
230			isreg = 0;
231		else
232			isreg = 1;
233	} else
234		isreg = 0;
235
236	if ((ofp = zopen(out, "w", bits)) == NULL) {
237		cwarn("%s", out);
238		goto err;
239	}
240	oreg <<= 1;
241	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
242		if (fwrite(buf, 1, nr, ofp) != nr) {
243			cwarn("%s", out);
244			goto err;
245		}
246
247	if (ferror(ifp))
248		error = in;
249	if (fclose(ifp))
250		if (error == NULL)
251			error = in;
252	if (fclose(ofp))
253		if (error == NULL)
254			error = out;
255	ifp = NULL;
256	ofp = NULL;
257	if (error) {
258		cwarn("%s", error);
259		goto err;
260	}
261
262	if (isreg && oreg) {
263		if (stat(out, &sb)) {
264			cwarn("%s", out);
265			goto err;
266		}
267
268		if (!force && sb.st_size >= isb.st_size) {
269			if (verbose)
270		(void)printf("%s: file would grow; left unmodified\n", in);
271			goto err;
272		}
273
274		setfile(out, &isb);
275
276		if (unlink(in))
277			cwarn("%s", in);
278
279		if (verbose) {
280			(void)printf("%s: ", out);
281			if (isb.st_size > sb.st_size)
282				(void)printf("%.0f%% compression\n",
283				    ((double)sb.st_size / isb.st_size) * 100.0);
284			else
285				(void)printf("%.0f%% expansion\n",
286				    ((double)isb.st_size / sb.st_size) * 100.0);
287		}
288	}
289	return;
290
291err:	if (ofp)
292		(void)fclose(ofp);
293	if (oreg == 2)
294		(void)unlink(out);
295	if (ifp)
296		(void)fclose(ifp);
297}
298
299static void
300decompress(const char *in, const char *out, int bits)
301{
302	size_t nr;
303	struct stat sb;
304	FILE *ifp, *ofp;
305	int exists, isreg, oreg;
306	u_char buf[BUFSIZ];
307
308	if (!isstdout) {
309		exists = !stat(out, &sb);
310		if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
311			return;
312		oreg = !exists || S_ISREG(sb.st_mode);
313	} else
314		oreg = 0;
315
316	ifp = ofp = NULL;
317	if ((ofp = fopen(out, "w")) == NULL) {
318		cwarn("%s", out);
319		return;
320	}
321
322	if ((ifp = zopen(in, "r", bits)) == NULL) {
323		cwarn("%s", in);
324		goto err;
325	}
326	if (!isstdin) {
327		if (stat(in, &sb)) {
328			cwarn("%s", in);
329			goto err;
330		}
331		if (!S_ISREG(sb.st_mode))
332			isreg = 0;
333		else
334			isreg = 1;
335	} else
336		isreg = 0;
337
338	oreg <<= 1;
339	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
340		if (fwrite(buf, 1, nr, ofp) != nr) {
341			cwarn("%s", out);
342			goto err;
343		}
344
345	if (ferror(ifp)) {
346		cwarn("%s", in);
347		goto err;
348	}
349	if (fclose(ifp)) {
350		ifp = NULL;
351		cwarn("%s", in);
352		goto err;
353	}
354	ifp = NULL;
355
356	if (fclose(ofp)) {
357		ofp = NULL;
358		cwarn("%s", out);
359		goto err;
360	}
361
362	if (isreg && oreg) {
363		setfile(out, &sb);
364
365		if (unlink(in))
366			cwarn("%s", in);
367	}
368	return;
369
370err:	if (ofp)
371		(void)fclose(ofp);
372	if (oreg == 2)
373		(void)unlink(out);
374	if (ifp)
375		(void)fclose(ifp);
376}
377
378static void
379setfile(const char *name, struct stat *fs)
380{
381	static struct timeval tv[2];
382
383	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
384
385	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
386	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
387	if (utimes(name, tv))
388		cwarn("utimes: %s", name);
389
390	/*
391	 * Changing the ownership probably won't succeed, unless we're root
392	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
393	 * the mode; current BSD behavior is to remove all setuid bits on
394	 * chown.  If chown fails, lose setuid/setgid bits.
395	 */
396	if (chown(name, fs->st_uid, fs->st_gid)) {
397		if (errno != EPERM)
398			cwarn("chown: %s", name);
399		fs->st_mode &= ~(S_ISUID|S_ISGID);
400	}
401	if (chmod(name, fs->st_mode))
402		cwarn("chown: %s", name);
403
404	/*
405	 * Restore the file's flags.  However, do this only if the original
406	 * file had any flags set; this avoids a warning on file-systems that
407	 * do not support flags.
408	 */
409	if (fs->st_flags != 0 && chflags(name, fs->st_flags))
410		cwarn("chflags: %s", name);
411}
412
413static int
414permission(const char *fname)
415{
416	int ch, first;
417
418	if (!isatty(fileno(stderr)))
419		return (0);
420	(void)fprintf(stderr, "overwrite %s? ", fname);
421	first = ch = getchar();
422	while (ch != '\n' && ch != EOF)
423		ch = getchar();
424	return (first == 'y');
425}
426
427static void
428usage(int iscompress)
429{
430	if (iscompress)
431		(void)fprintf(stderr,
432		    "usage: compress [-cdfv] [-b bits] [file ...]\n");
433	else
434		(void)fprintf(stderr,
435		    "usage: uncompress [-cdfv] [-b bits] [file ...]\n");
436	exit(1);
437}
438
439static void
440cwarnx(const char *fmt, ...)
441{
442	va_list ap;
443
444	va_start(ap, fmt);
445	vwarnx(fmt, ap);
446	va_end(ap);
447	eval = 1;
448}
449
450static void
451cwarn(const char *fmt, ...)
452{
453	va_list ap;
454
455	va_start(ap, fmt);
456	vwarn(fmt, ap);
457	va_end(ap);
458	eval = 1;
459}
460