compress/compress.c

   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
  35 static 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
  42 static char sccsid[] = "@(#)compress.c  8.2 (Berkeley) 1/7/94";
  43 #endif
  44 #endif
  45
  46 #include <sys/cdefs.h>
  47 __FBSDID("$FreeBSD: src/usr.bin/compress/compress.c,v 1.21 2003/06/14 13:41:31 trhodes Exp $");
  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
  63 void    compress(const char *, const char *, int);
  64 void    cwarn(const char *, ...) __printflike(1, 2);
  65 void    cwarnx(const char *, ...) __printflike(1, 2);
  66 void    decompress(const char *, const char *, int);
  67 int     permission(const char *);
  68 void    setfile(const char *, struct stat *);
  69 void    usage(int);
  70
  71 int eval, force, verbose, cat;
  72
  73 int
  74 main(int argc, char *argv[])
  75 {
  76         enum {COMPRESS, DECOMPRESS} style;
  77         size_t len;
  78         int bits, 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                 cat = 1;
 125                 switch(style) {
 126                 case COMPRESS:
 127                         (void)compress("/dev/stdin", "/dev/stdout", bits);
 128                         break;
 129                 case DECOMPRESS:
 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                 switch(style) {
 141                 case COMPRESS:
 142                         if (strcmp(*argv, "-") == 0) {
 143                                 cat = 1;
 144                                 compress("/dev/stdin", "/dev/stdout", bits);
 145                                 break;
 146                         } else if (cat) {
 147                                 compress(*argv, "/dev/stdout", bits);
 148                                 break;
 149                         }
 150                         if ((p = rindex(*argv, '.')) != NULL &&
 151                             !strcmp(p, ".Z")) {
 152                                 cwarnx("%s: name already has trailing .Z",
 153                                     *argv);
 154                                 break;
 155                         }
 156                         len = strlen(*argv);
 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                         compress(*argv, newname, bits);
 166                         break;
 167                 case DECOMPRESS:
 168                         if (strcmp(*argv, "-") == 0) {
 169                                 cat = 1;
 170                                 decompress("/dev/stdin", "/dev/stdout", bits);
 171                                 break;
 172                         }
 173                         len = strlen(*argv);
 174                         if ((p = rindex(*argv, '.')) == NULL ||
 175                             strcmp(p, ".Z")) {
 176                                 if (len > sizeof(newname) - 3) {
 177                                         cwarnx("%s: name too long", *argv);
 178                                         break;
 179                                 }
 180                                 memmove(newname, *argv, len);
 181                                 newname[len] = '.';
 182                                 newname[len + 1] = 'Z';
 183                                 newname[len + 2] = '\0';
 184                                 decompress(newname,
 185                                     cat ? "/dev/stdout" : *argv, bits);
 186                         } else {
 187                                 if (len - 2 > sizeof(newname) - 1) {
 188                                         cwarnx("%s: name too long", *argv);
 189                                         break;
 190                                 }
 191                                 memmove(newname, *argv, len - 2);
 192                                 newname[len - 2] = '\0';
 193                                 decompress(*argv,
 194                                     cat ? "/dev/stdout" : newname, bits);
 195                         }
 196                         break;
 197                 }
 198         exit (eval);
 199 }
 200
 201 void
 202 compress(const char *in, const char *out, int bits)
 203 {
 204         size_t nr;
 205         struct stat isb, sb;
 206         FILE *ifp, *ofp;
 207         int exists, isreg, oreg;
 208         u_char buf[1024];
 209
 210         exists = !stat(out, &sb);
 211         if (!force && exists && S_ISREG(sb.st_mode) && !cat && !permission(out)) {
 212                 cwarnx("%s already exists", out);
 213                 return;
 214         }
 215         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 216
 217         ifp = ofp = NULL;
 218         if ((ifp = fopen(in, "r")) == NULL) {
 219                 cwarn("%s", in);
 220                 return;
 221         }
 222         if (stat(in, &isb)) {           /* DON'T FSTAT! */
 223                 cwarn("%s", in);
 224                 goto err;
 225         }
 226         if (!S_ISREG(isb.st_mode))
 227                 isreg = 0;
 228
 229         if ((ofp = zopen(out, "w", bits)) == NULL) {
 230                 cwarn("%s", out);
 231                 goto err;
 232         }
 233         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 234                 if (fwrite(buf, 1, nr, ofp) != nr) {
 235                         cwarn("%s", out);
 236                         goto err;
 237                 }
 238
 239         if (ferror(ifp) || fclose(ifp)) {
 240                 cwarn("%s", in);
 241                 goto err;
 242         }
 243         ifp = NULL;
 244
 245         if (fclose(ofp)) {
 246                 cwarn("%s", out);
 247                 goto err;
 248         }
 249         ofp = NULL;
 250
 251         if (!cat && isreg) {
 252                 if (stat(out, &sb)) {
 253                         cwarn("%s", out);
 254                         goto err;
 255                 }
 256
 257                 if (!force && sb.st_size >= isb.st_size) {
 258                         if (verbose)
 259                 (void)fprintf(stderr, "%s: file would grow; left unmodified\n",
 260                     in);
 261                         eval = 2;
 262                         if (unlink(out))
 263                                 cwarn("%s", out);
 264                         goto err;
 265                 }
 266
 267                 setfile(out, &isb);
 268
 269                 if (unlink(in))
 270                         cwarn("%s", in);
 271
 272                 if (verbose) {
 273                         (void)fprintf(stderr, "%s: ", out);
 274                         if (isb.st_size > sb.st_size)
 275                                 (void)fprintf(stderr, "%.0f%% compression\n",
 276                                     ((float)sb.st_size / isb.st_size) * 100.0);
 277                         else
 278                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 279                                     ((float)isb.st_size / sb.st_size) * 100.0);
 280                 }
 281         }
 282         return;
 283
 284 err:    if (ofp) {
 285                 if (!cat && oreg)
 286                         (void)unlink(out);
 287                 (void)fclose(ofp);
 288         }
 289         if (ifp)
 290                 (void)fclose(ifp);
 291 }
 292
 293 void
 294 decompress(const char *in, const char *out, int bits)
 295 {
 296         size_t nr;
 297         struct stat sb;
 298         FILE *ifp, *ofp;
 299         int exists, isreg, oreg;
 300         u_char buf[1024];
 301
 302         exists = !stat(out, &sb);
 303         if (!force && exists && S_ISREG(sb.st_mode) && !cat && !permission(out)) {
 304                 cwarnx("%s already exists", out);
 305                 return;
 306         }
 307         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 308
 309         ifp = ofp = NULL;
 310         if ((ifp = zopen(in, "r", bits)) == NULL) {
 311                 cwarn("%s", in);
 312                 return;
 313         }
 314         if (stat(in, &sb)) {
 315                 cwarn("%s", in);
 316                 goto err;
 317         }
 318         if (!S_ISREG(sb.st_mode))
 319                 isreg = 0;
 320
 321         /*
 322          * Try to read the first few uncompressed bytes from the input file
 323          * before blindly truncating the output file.
 324          */
 325         if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
 326                 cwarn("%s", in);
 327                 (void)fclose(ifp);
 328                 return;
 329         }
 330         if ((ofp = fopen(out, "w")) == NULL ||
 331             (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
 332                 cwarn("%s", out);
 333                 (void)fclose(ifp);
 334                 return;
 335         }
 336
 337         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 338                 if (fwrite(buf, 1, nr, ofp) != nr) {
 339                         cwarn("%s", out);
 340                         goto err;
 341                 }
 342
 343         if (ferror(ifp) || fclose(ifp)) {
 344                 cwarn("%s", in);
 345                 goto err;
 346         }
 347         ifp = NULL;
 348
 349         if (fclose(ofp)) {
 350                 cwarn("%s", out);
 351                 goto err;
 352         }
 353
 354         if (!cat && isreg) {
 355                 setfile(out, &sb);
 356
 357                 if (unlink(in))
 358                         cwarn("%s", in);
 359                 if (verbose) {
 360                         struct stat isb = sb;
 361                         stat(out, &sb);
 362                         (void)fprintf(stderr, "%s: ", out);
 363                         if (isb.st_size > sb.st_size)
 364                                 (void)fprintf(stderr, "%.0f%% compression\n",
 365                                     ((float)sb.st_size / isb.st_size) * 100.0);
 366                         else
 367                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 368                                     ((float)isb.st_size / sb.st_size) * 100.0);
 369                 }
 370         }
 371         return;
 372
 373 err:    if (ofp) {
 374                 if (!cat && oreg)
 375                         (void)unlink(out);
 376                 (void)fclose(ofp);
 377         }
 378         if (ifp)
 379                 (void)fclose(ifp);
 380 }
 381
 382 void
 383 setfile(const char *name, struct stat *fs)
 384 {
 385         static struct timeval tv[2];
 386
 387         fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
 388
 389         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 390         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 391         if (utimes(name, tv))
 392                 cwarn("utimes: %s", name);
 393
 394         /*
 395          * Changing the ownership probably won't succeed, unless we're root
 396          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 397          * the mode; current BSD behavior is to remove all setuid bits on
 398          * chown.  If chown fails, lose setuid/setgid bits.
 399          */
 400         if (chown(name, fs->st_uid, fs->st_gid)) {
 401                 if (errno != EPERM)
 402                         cwarn("chown: %s", name);
 403                 fs->st_mode &= ~(S_ISUID|S_ISGID);
 404         }
 405         if (chmod(name, fs->st_mode) && errno != EOPNOTSUPP)
 406                 cwarn("chmod: %s", name);
 407
 408         if (chflags(name, fs->st_flags) && errno != EOPNOTSUPP)
 409                 cwarn("chflags: %s", name);
 410 }
 411
 412 int
 413 permission(const char *fname)
 414 {
 415         int ch, first;
 416
 417         if (!isatty(fileno(stderr)))
 418                 return (0);
 419         (void)fprintf(stderr, "overwrite %s? ", fname);
 420         first = ch = getchar();
 421         while (ch != '\n' && ch != EOF)
 422                 ch = getchar();
 423         return (first == 'y');
 424 }
 425
 426 void
 427 usage(int iscompress)
 428 {
 429         if (iscompress)
 430                 (void)fprintf(stderr,
 431                     "usage: compress [-cfv] [-b bits] [file ...]\n");
 432         else
 433                 (void)fprintf(stderr,
 434                     "usage: uncompress [-cfv] [-b bits] [file ...]\n");
 435         exit(1);
 436 }
 437
 438 void
 439 cwarnx(const char *fmt, ...)
 440 {
 441         va_list ap;
 442
 443         va_start(ap, fmt);
 444         vwarnx(fmt, ap);
 445         va_end(ap);
 446         eval = 1;
 447 }
 448
 449 void
 450 cwarn(const char *fmt, ...)
 451 {
 452         va_list ap;
 453
 454         va_start(ap, fmt);
 455         vwarn(fmt, ap);
 456         va_end(ap);
 457         eval = 1;
 458 }