1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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/param.h>
33 #include <sys/stat.h>
34 #include <sys/time.h>
35
36 #include <err.h>
37 #include <errno.h>
38 #include <fcntl.h>
39 #include <stdarg.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44
45 #include "zopen.h"
46
47 static void compress(const char *, const char *, int);
48 static void cwarn(const char *, ...) __printflike(1, 2);
49 static void cwarnx(const char *, ...) __printflike(1, 2);
50 static void decompress(const char *, const char *, int);
51 static int permission(const char *);
52 static void setfile(const char *, struct stat *);
53 static void usage(int);
54
55 static int eval, force, verbose;
56
57 int
main(int argc,char * argv[])58 main(int argc, char *argv[])
59 {
60 enum {COMPRESS, DECOMPRESS} style;
61 size_t len;
62 int bits, cat, ch;
63 char *p, newname[MAXPATHLEN];
64
65 cat = 0;
66 if ((p = strrchr(argv[0], '/')) == NULL)
67 p = argv[0];
68 else
69 ++p;
70 if (!strcmp(p, "uncompress"))
71 style = DECOMPRESS;
72 else if (!strcmp(p, "compress"))
73 style = COMPRESS;
74 else if (!strcmp(p, "zcat")) {
75 cat = 1;
76 style = DECOMPRESS;
77 } else
78 errx(1, "unknown program name");
79
80 bits = 0;
81 while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
82 switch(ch) {
83 case 'b':
84 bits = strtol(optarg, &p, 10);
85 if (*p)
86 errx(1, "illegal bit count -- %s", optarg);
87 break;
88 case 'c':
89 cat = 1;
90 break;
91 case 'd': /* Backward compatible. */
92 style = DECOMPRESS;
93 break;
94 case 'f':
95 force = 1;
96 break;
97 case 'v':
98 verbose = 1;
99 break;
100 case '?':
101 default:
102 usage(style == COMPRESS);
103 }
104 argc -= optind;
105 argv += optind;
106
107 if (argc == 0) {
108 switch(style) {
109 case COMPRESS:
110 (void)compress("/dev/stdin", "/dev/stdout", bits);
111 break;
112 case DECOMPRESS:
113 (void)decompress("/dev/stdin", "/dev/stdout", bits);
114 break;
115 }
116 exit (eval);
117 }
118
119 if (cat == 1 && style == COMPRESS && argc > 1)
120 errx(1, "the -c option permits only a single file argument");
121
122 for (; *argv; ++argv)
123 switch(style) {
124 case COMPRESS:
125 if (strcmp(*argv, "-") == 0) {
126 compress("/dev/stdin", "/dev/stdout", bits);
127 break;
128 } else if (cat) {
129 compress(*argv, "/dev/stdout", bits);
130 break;
131 }
132 if ((p = strrchr(*argv, '.')) != NULL &&
133 !strcmp(p, ".Z")) {
134 cwarnx("%s: name already has trailing .Z",
135 *argv);
136 break;
137 }
138 len = strlen(*argv);
139 if (len > sizeof(newname) - 3) {
140 cwarnx("%s: name too long", *argv);
141 break;
142 }
143 memmove(newname, *argv, len);
144 newname[len] = '.';
145 newname[len + 1] = 'Z';
146 newname[len + 2] = '\0';
147 compress(*argv, newname, bits);
148 break;
149 case DECOMPRESS:
150 if (strcmp(*argv, "-") == 0) {
151 decompress("/dev/stdin", "/dev/stdout", bits);
152 break;
153 }
154 len = strlen(*argv);
155 if ((p = strrchr(*argv, '.')) == NULL ||
156 strcmp(p, ".Z")) {
157 if (len > sizeof(newname) - 3) {
158 cwarnx("%s: name too long", *argv);
159 break;
160 }
161 memmove(newname, *argv, len);
162 newname[len] = '.';
163 newname[len + 1] = 'Z';
164 newname[len + 2] = '\0';
165 decompress(newname,
166 cat ? "/dev/stdout" : *argv, bits);
167 } else {
168 if (len - 2 > sizeof(newname) - 1) {
169 cwarnx("%s: name too long", *argv);
170 break;
171 }
172 memmove(newname, *argv, len - 2);
173 newname[len - 2] = '\0';
174 decompress(*argv,
175 cat ? "/dev/stdout" : newname, bits);
176 }
177 break;
178 }
179 exit (eval);
180 }
181
182 static void
compress(const char * in,const char * out,int bits)183 compress(const char *in, const char *out, int bits)
184 {
185 size_t nr;
186 struct stat isb, sb;
187 FILE *ifp, *ofp;
188 int exists, isreg, oreg;
189 u_char buf[1024];
190
191 exists = !stat(out, &sb);
192 if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
193 return;
194 isreg = oreg = !exists || S_ISREG(sb.st_mode);
195
196 ifp = ofp = NULL;
197 if ((ifp = fopen(in, "r")) == NULL) {
198 cwarn("%s", in);
199 return;
200 }
201 if (stat(in, &isb)) { /* DON'T FSTAT! */
202 cwarn("%s", in);
203 goto err;
204 }
205 if (!S_ISREG(isb.st_mode))
206 isreg = 0;
207
208 if ((ofp = zopen(out, "w", bits)) == NULL) {
209 cwarn("%s", out);
210 goto err;
211 }
212 while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
213 if (fwrite(buf, 1, nr, ofp) != nr) {
214 cwarn("%s", out);
215 goto err;
216 }
217
218 if (ferror(ifp) || fclose(ifp)) {
219 cwarn("%s", in);
220 goto err;
221 }
222 ifp = NULL;
223
224 if (fclose(ofp)) {
225 cwarn("%s", out);
226 goto err;
227 }
228 ofp = NULL;
229
230 if (isreg) {
231 if (stat(out, &sb)) {
232 cwarn("%s", out);
233 goto err;
234 }
235
236 if (!force && sb.st_size >= isb.st_size) {
237 if (verbose)
238 (void)fprintf(stderr, "%s: file would grow; left unmodified\n",
239 in);
240 eval = 2;
241 if (unlink(out))
242 cwarn("%s", out);
243 goto err;
244 }
245
246 setfile(out, &isb);
247
248 if (unlink(in))
249 cwarn("%s", in);
250
251 if (verbose) {
252 (void)fprintf(stderr, "%s: ", out);
253 if (isb.st_size > sb.st_size)
254 (void)fprintf(stderr, "%.0f%% compression\n",
255 ((float)sb.st_size / isb.st_size) * 100.0);
256 else
257 (void)fprintf(stderr, "%.0f%% expansion\n",
258 ((float)isb.st_size / sb.st_size) * 100.0);
259 }
260 }
261 return;
262
263 err: if (ofp) {
264 if (oreg)
265 (void)unlink(out);
266 (void)fclose(ofp);
267 }
268 if (ifp)
269 (void)fclose(ifp);
270 }
271
272 static void
decompress(const char * in,const char * out,int bits)273 decompress(const char *in, const char *out, int bits)
274 {
275 size_t nr;
276 struct stat sb;
277 FILE *ifp, *ofp;
278 int exists, isreg, oreg;
279 u_char buf[1024];
280
281 exists = !stat(out, &sb);
282 if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
283 return;
284 isreg = oreg = !exists || S_ISREG(sb.st_mode);
285
286 ifp = ofp = NULL;
287 if ((ifp = zopen(in, "r", bits)) == NULL) {
288 cwarn("%s", in);
289 return;
290 }
291 if (stat(in, &sb)) {
292 cwarn("%s", in);
293 goto err;
294 }
295 if (!S_ISREG(sb.st_mode))
296 isreg = 0;
297
298 /*
299 * Try to read the first few uncompressed bytes from the input file
300 * before blindly truncating the output file.
301 */
302 if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
303 cwarn("%s", in);
304 (void)fclose(ifp);
305 return;
306 }
307 if ((ofp = fopen(out, "w")) == NULL ||
308 (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
309 cwarn("%s", out);
310 if (ofp)
311 (void)fclose(ofp);
312 (void)fclose(ifp);
313 return;
314 }
315
316 while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
317 if (fwrite(buf, 1, nr, ofp) != nr) {
318 cwarn("%s", out);
319 goto err;
320 }
321
322 if (ferror(ifp) || fclose(ifp)) {
323 cwarn("%s", in);
324 goto err;
325 }
326 ifp = NULL;
327
328 if (fclose(ofp)) {
329 cwarn("%s", out);
330 goto err;
331 }
332
333 if (isreg) {
334 setfile(out, &sb);
335
336 if (unlink(in))
337 cwarn("%s", in);
338 }
339 return;
340
341 err: if (ofp) {
342 if (oreg)
343 (void)unlink(out);
344 (void)fclose(ofp);
345 }
346 if (ifp)
347 (void)fclose(ifp);
348 }
349
350 static void
setfile(const char * name,struct stat * fs)351 setfile(const char *name, struct stat *fs)
352 {
353 static struct timespec tspec[2];
354
355 fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
356
357 tspec[0] = fs->st_atim;
358 tspec[1] = fs->st_mtim;
359 if (utimensat(AT_FDCWD, name, tspec, 0))
360 cwarn("utimensat: %s", name);
361
362 /*
363 * Changing the ownership probably won't succeed, unless we're root
364 * or POSIX_CHOWN_RESTRICTED is not set. Set uid/gid before setting
365 * the mode; current BSD behavior is to remove all setuid bits on
366 * chown. If chown fails, lose setuid/setgid bits.
367 */
368 if (chown(name, fs->st_uid, fs->st_gid)) {
369 if (errno != EPERM)
370 cwarn("chown: %s", name);
371 fs->st_mode &= ~(S_ISUID|S_ISGID);
372 }
373 if (chmod(name, fs->st_mode) && errno != EOPNOTSUPP)
374 cwarn("chmod: %s", name);
375
376 if (chflags(name, fs->st_flags) && errno != EOPNOTSUPP)
377 cwarn("chflags: %s", name);
378 }
379
380 static int
permission(const char * fname)381 permission(const char *fname)
382 {
383 int ch, first;
384
385 if (!isatty(fileno(stderr)))
386 return (0);
387 (void)fprintf(stderr, "overwrite %s? ", fname);
388 first = ch = getchar();
389 while (ch != '\n' && ch != EOF)
390 ch = getchar();
391 return (first == 'y');
392 }
393
394 static void
usage(int iscompress)395 usage(int iscompress)
396 {
397 if (iscompress)
398 (void)fprintf(stderr,
399 "usage: compress [-cfv] [-b bits] [file ...]\n");
400 else
401 (void)fprintf(stderr,
402 "usage: uncompress [-c] [-b bits] [file ...]\n");
403 exit(1);
404 }
405
406 static void
cwarnx(const char * fmt,...)407 cwarnx(const char *fmt, ...)
408 {
409 va_list ap;
410
411 va_start(ap, fmt);
412 vwarnx(fmt, ap);
413 va_end(ap);
414 eval = 1;
415 }
416
417 static void
cwarn(const char * fmt,...)418 cwarn(const char *fmt, ...)
419 {
420 va_list ap;
421
422 va_start(ap, fmt);
423 vwarn(fmt, ap);
424 va_end(ap);
425 eval = 1;
426 }
427