1 /* $NetBSD: compress.c,v 1.29 2022/05/22 21:39:44 rillig 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
40 static char sccsid[] = "@(#)compress.c 8.2 (Berkeley) 1/7/94";
41 #else
42 __RCSID("$NetBSD: compress.c,v 1.29 2022/05/22 21:39:44 rillig 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
58 static void compress(const char *, const char *, int);
59 static void cwarn(const char *, ...) __printflike(1, 2);
60 static void cwarnx(const char *, ...) __printflike(1, 2);
61 static void decompress(const char *, const char *, int);
62 static int permission(const char *);
63 static void setfile(const char *, struct stat *);
64 __dead static void usage(int);
65
66 extern FILE *zopen(const char *fname, const char *mode, int bits);
67
68 static int eval, force, verbose;
69 static int isstdout, isstdin;
70
71 int
main(int argc,char ** argv)72 main(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 } else
91 errx(1, "unknown program name");
92
93 bits = cat = 0;
94 while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
95 switch (ch) {
96 case 'b':
97 bits = strtol(optarg, &p, 10);
98 if (*p)
99 errx(1, "illegal bit count -- %s", optarg);
100 break;
101 case 'c':
102 cat = 1;
103 break;
104 case 'd': /* Backward compatible. */
105 style = DECOMPRESS;
106 break;
107 case 'f':
108 force = 1;
109 break;
110 case 'v':
111 verbose = 1;
112 break;
113 case '?':
114 default:
115 usage(style == COMPRESS);
116 }
117 argc -= optind;
118 argv += optind;
119
120 if (argc == 0) {
121 switch (style) {
122 case COMPRESS:
123 isstdout = 1;
124 isstdin = 1;
125 (void)compress("/dev/stdin", "/dev/stdout", bits);
126 break;
127 case DECOMPRESS:
128 isstdout = 1;
129 isstdin = 1;
130 (void)decompress("/dev/stdin", "/dev/stdout", bits);
131 break;
132 }
133 exit (eval);
134 }
135
136 if (cat == 1 && argc > 1)
137 errx(1, "the -c option permits only a single file argument");
138
139 for (; *argv; ++argv) {
140 isstdout = 0;
141 switch (style) {
142 case COMPRESS:
143 if (cat) {
144 isstdout = 1;
145 compress(*argv, "/dev/stdout", bits);
146 break;
147 }
148 if ((p = strrchr(*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 len = strlen(*argv);
167 if ((p = strrchr(*argv, '.')) == NULL ||
168 strcmp(p, ".Z")) {
169 if (len > sizeof(newname) - 3) {
170 cwarnx("%s: name too long", *argv);
171 break;
172 }
173 memmove(newname, *argv, len);
174 newname[len] = '.';
175 newname[len + 1] = 'Z';
176 newname[len + 2] = '\0';
177 decompress(newname,
178 cat ? "/dev/stdout" : *argv, bits);
179 if (cat)
180 isstdout = 1;
181 } else {
182 if (len - 2 > sizeof(newname) - 1) {
183 cwarnx("%s: name too long", *argv);
184 break;
185 }
186 memmove(newname, *argv, len - 2);
187 newname[len - 2] = '\0';
188 decompress(*argv,
189 cat ? "/dev/stdout" : newname, bits);
190 if (cat)
191 isstdout = 1;
192 }
193 break;
194 }
195 }
196 exit (eval);
197 }
198
199 static void
compress(const char * in,const char * out,int bits)200 compress(const char *in, const char *out, int bits)
201 {
202 size_t nr;
203 struct stat isb, sb;
204 const char *error = NULL;
205 FILE *ifp, *ofp;
206 int exists, isreg, oreg;
207 u_char buf[BUFSIZ];
208
209 if (!isstdout) {
210 exists = !stat(out, &sb);
211 if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
212 return;
213 oreg = !exists || S_ISREG(sb.st_mode);
214 } else
215 oreg = 0;
216
217 ifp = ofp = NULL;
218 if ((ifp = fopen(in, "r")) == NULL) {
219 cwarn("%s", in);
220 return;
221 }
222
223 if (!isstdin) {
224 if (stat(in, &isb)) { /* DON'T FSTAT! */
225 cwarn("%s", in);
226 goto err;
227 }
228 if (!S_ISREG(isb.st_mode))
229 isreg = 0;
230 else
231 isreg = 1;
232 } else
233 isreg = 0;
234
235 if ((ofp = zopen(out, "w", bits)) == NULL) {
236 cwarn("%s", out);
237 goto err;
238 }
239 oreg <<= 1;
240 while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
241 if (fwrite(buf, 1, nr, ofp) != nr) {
242 cwarn("%s", out);
243 goto err;
244 }
245
246 if (ferror(ifp))
247 error = in;
248 if (fclose(ifp))
249 if (error == NULL)
250 error = in;
251 if (fclose(ofp))
252 if (error == NULL)
253 error = out;
254 ifp = NULL;
255 ofp = NULL;
256 if (error) {
257 cwarn("%s", error);
258 goto err;
259 }
260
261 if (isreg && oreg) {
262 if (stat(out, &sb)) {
263 cwarn("%s", out);
264 goto err;
265 }
266
267 if (!force && sb.st_size >= isb.st_size) {
268 if (verbose)
269 (void)printf("%s: file would grow; left unmodified\n", in);
270 goto err;
271 }
272
273 setfile(out, &isb);
274
275 if (unlink(in))
276 cwarn("%s", in);
277
278 if (verbose) {
279 (void)printf("%s: ", out);
280 if (isb.st_size > sb.st_size)
281 (void)printf("%.0f%% compression\n",
282 ((double)sb.st_size / isb.st_size) * 100.0);
283 else
284 (void)printf("%.0f%% expansion\n",
285 ((double)isb.st_size / sb.st_size) * 100.0);
286 }
287 }
288 return;
289
290 err: if (ofp)
291 (void)fclose(ofp);
292 if (oreg == 2)
293 (void)unlink(out);
294 if (ifp)
295 (void)fclose(ifp);
296 }
297
298 static void
decompress(const char * in,const char * out,int bits)299 decompress(const char *in, const char *out, int bits)
300 {
301 size_t nr;
302 struct stat sb;
303 FILE *ifp, *ofp;
304 int exists, isreg, oreg;
305 u_char buf[BUFSIZ];
306
307 if (!isstdout) {
308 exists = !stat(out, &sb);
309 if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
310 return;
311 oreg = !exists || S_ISREG(sb.st_mode);
312 } else
313 oreg = 0;
314
315 ifp = ofp = NULL;
316
317 if ((ifp = zopen(in, "r", bits)) == NULL) {
318 cwarn("%s", in);
319 goto err;
320 }
321 if (!isstdin) {
322 if (stat(in, &sb)) {
323 cwarn("%s", in);
324 goto err;
325 }
326 if (!S_ISREG(sb.st_mode))
327 isreg = 0;
328 else
329 isreg = 1;
330 } else
331 isreg = 0;
332 if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
333 cwarn("%s", in);
334 goto err;
335 }
336
337 if ((ofp = fopen(out, "w")) == NULL) {
338 cwarn("%s", out);
339 goto err;
340 }
341 if (fwrite(buf, 1, nr, ofp) != nr) {
342 cwarn("%s", out);
343 goto err;
344 }
345
346 oreg <<= 1;
347 while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
348 if (fwrite(buf, 1, nr, ofp) != nr) {
349 cwarn("%s", out);
350 goto err;
351 }
352
353 if (ferror(ifp)) {
354 cwarn("%s", in);
355 goto err;
356 }
357 if (fclose(ifp)) {
358 ifp = NULL;
359 cwarn("%s", in);
360 goto err;
361 }
362 ifp = NULL;
363
364 if (fclose(ofp)) {
365 ofp = NULL;
366 cwarn("%s", out);
367 goto err;
368 }
369
370 if (isreg && oreg) {
371 setfile(out, &sb);
372
373 if (unlink(in))
374 cwarn("%s", in);
375 }
376 return;
377
378 err: if (ofp)
379 (void)fclose(ofp);
380 if (oreg == 2)
381 (void)unlink(out);
382 if (ifp)
383 (void)fclose(ifp);
384 }
385
386 static void
setfile(const char * name,struct stat * fs)387 setfile(const char *name, struct stat *fs)
388 {
389 static struct timeval tv[2];
390
391 fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
392
393 TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
394 TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
395 if (utimes(name, tv))
396 cwarn("utimes: %s", name);
397
398 /*
399 * Changing the ownership probably won't succeed, unless we're root
400 * or POSIX_CHOWN_RESTRICTED is not set. Set uid/gid before setting
401 * the mode; current BSD behavior is to remove all setuid bits on
402 * chown. If chown fails, lose setuid/setgid bits.
403 */
404 if (chown(name, fs->st_uid, fs->st_gid)) {
405 if (errno != EPERM)
406 cwarn("chown: %s", name);
407 fs->st_mode &= ~(S_ISUID|S_ISGID);
408 }
409 if (chmod(name, fs->st_mode))
410 cwarn("chown: %s", name);
411
412 /*
413 * Restore the file's flags. However, do this only if the original
414 * file had any flags set; this avoids a warning on file-systems that
415 * do not support flags.
416 */
417 if (fs->st_flags != 0 && chflags(name, fs->st_flags))
418 cwarn("chflags: %s", name);
419 }
420
421 static int
permission(const char * fname)422 permission(const char *fname)
423 {
424 int ch, first;
425
426 if (!isatty(fileno(stderr)))
427 return (0);
428 (void)fprintf(stderr, "overwrite %s? ", fname);
429 first = ch = getchar();
430 while (ch != '\n' && ch != EOF)
431 ch = getchar();
432 return (first == 'y');
433 }
434
435 static void
usage(int iscompress)436 usage(int iscompress)
437 {
438 if (iscompress)
439 (void)fprintf(stderr,
440 "usage: compress [-cdfv] [-b bits] [file ...]\n");
441 else
442 (void)fprintf(stderr,
443 "usage: uncompress [-cdfv] [-b bits] [file ...]\n");
444 exit(1);
445 }
446
447 static void
cwarnx(const char * fmt,...)448 cwarnx(const char *fmt, ...)
449 {
450 va_list ap;
451
452 va_start(ap, fmt);
453 vwarnx(fmt, ap);
454 va_end(ap);
455 eval = 1;
456 }
457
458 static void
cwarn(const char * fmt,...)459 cwarn(const char *fmt, ...)
460 {
461 va_list ap;
462
463 va_start(ap, fmt);
464 vwarn(fmt, ap);
465 va_end(ap);
466 eval = 1;
467 }
468