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 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 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 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 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 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 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 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 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
Indexes created Thu Sep 25 06:09:39 GMT 2025