usr.bin/compress/compress.c

   1 /*      $NetBSD: compress.c,v 1.24 2008/07/21 14:19:22 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
  40 static char sccsid[] = "@(#)compress.c  8.2 (Berkeley) 1/7/94";
  41 #else
  42 __RCSID("$NetBSD: compress.c,v 1.24 2008/07/21 14:19:22 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
  58 void    compress(const char *, const char *, int);
  59 void    cwarn(const char *, ...) __attribute__((__format__(__printf__,1,2)));
  60 void    cwarnx(const char *, ...) __attribute__((__format__(__printf__,1,2)));
  61 void    decompress(const char *, const char *, int);
  62 int     permission(const char *);
  63 void    setfile(const char *, struct stat *);
  64 void    usage(int);
  65
  66 int     main(int, char *[]);
  67 extern FILE *zopen(const char *fname, const char *mode, int bits);
  68
  69 int eval, force, verbose;
  70 int isstdout, isstdin;
  71
  72 int
  73 main(int argc, char **argv)
  74 {
  75         enum {COMPRESS, DECOMPRESS} style = COMPRESS;
  76         size_t len;
  77         int bits, cat, ch;
  78         char *p, newname[MAXPATHLEN];
  79
  80         if ((p = strrchr(argv[0], '/')) == NULL)
  81                 p = argv[0];
  82         else
  83                 ++p;
  84         if (!strcmp(p, "uncompress"))
  85                 style = DECOMPRESS;
  86         else if (!strcmp(p, "compress"))
  87                 style = COMPRESS;
  88         else if (!strcmp(p, "zcat")) {
  89                 style = DECOMPRESS;
  90                 cat = 1;
  91         }
  92         else
  93                 errx(1, "unknown program name");
  94
  95         bits = cat = 0;
  96         while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
  97                 switch(ch) {
  98                 case 'b':
  99                         bits = strtol(optarg, &p, 10);
 100                         if (*p)
 101                                 errx(1, "illegal bit count -- %s", optarg);
 102                         break;
 103                 case 'c':
 104                         cat = 1;
 105                         break;
 106                 case 'd':               /* Backward compatible. */
 107                         style = DECOMPRESS;
 108                         break;
 109                 case 'f':
 110                         force = 1;
 111                         break;
 112                 case 'v':
 113                         verbose = 1;
 114                         break;
 115                 case '?':
 116                 default:
 117                         usage(style == COMPRESS);
 118                 }
 119         argc -= optind;
 120         argv += optind;
 121
 122         if (argc == 0) {
 123                 switch(style) {
 124                 case COMPRESS:
 125                         isstdout = 1;
 126                         isstdin = 1;
 127                         (void)compress("/dev/stdin", "/dev/stdout", bits);
 128                         break;
 129                 case DECOMPRESS:
 130                         isstdout = 1;
 131                         isstdin = 1;
 132                         (void)decompress("/dev/stdin", "/dev/stdout", bits);
 133                         break;
 134                 }
 135                 exit (eval);
 136         }
 137
 138         if (cat == 1 && argc > 1)
 139                 errx(1, "the -c option permits only a single file argument");
 140
 141         for (; *argv; ++argv) {
 142                 isstdout = 0;
 143                 switch(style) {
 144                 case COMPRESS:
 145                         if (cat) {
 146                                 isstdout = 1;
 147                                 compress(*argv, "/dev/stdout", bits);
 148                                 break;
 149                         }
 150                         if ((p = strrchr(*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                         len = strlen(*argv);
 169                         if ((p = strrchr(*argv, '.')) == NULL ||
 170                             strcmp(p, ".Z")) {
 171                                 if (len > sizeof(newname) - 3) {
 172                                         cwarnx("%s: name too long", *argv);
 173                                         break;
 174                                 }
 175                                 memmove(newname, *argv, len);
 176                                 newname[len] = '.';
 177                                 newname[len + 1] = 'Z';
 178                                 newname[len + 2] = '\0';
 179                                 decompress(newname,
 180                                     cat ? "/dev/stdout" : *argv, bits);
 181                                 if (cat)
 182                                         isstdout = 1;
 183                         } else {
 184                                 if (len - 2 > sizeof(newname) - 1) {
 185                                         cwarnx("%s: name too long", *argv);
 186                                         break;
 187                                 }
 188                                 memmove(newname, *argv, len - 2);
 189                                 newname[len - 2] = '\0';
 190                                 decompress(*argv,
 191                                     cat ? "/dev/stdout" : newname, bits);
 192                                 if (cat)
 193                                         isstdout = 1;
 194                         }
 195                         break;
 196                 }
 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         const char *error = NULL;
 207         FILE *ifp, *ofp;
 208         int exists, isreg, oreg;
 209         u_char buf[BUFSIZ];
 210
 211         if (!isstdout) {
 212                 exists = !stat(out, &sb);
 213                 if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
 214                         return;
 215                 oreg = !exists || S_ISREG(sb.st_mode);
 216         } else
 217                 oreg = 0;
 218
 219         ifp = ofp = NULL;
 220         if ((ifp = fopen(in, "r")) == NULL) {
 221                 cwarn("%s", in);
 222                 return;
 223         }
 224
 225         if (!isstdin) {
 226                 if (stat(in, &isb)) {           /* DON'T FSTAT! */
 227                         cwarn("%s", in);
 228                         goto err;
 229                 }
 230                 if (!S_ISREG(isb.st_mode))
 231                         isreg = 0;
 232                 else
 233                         isreg = 1;
 234         } else
 235                 isreg = 0;
 236
 237         if ((ofp = zopen(out, "w", bits)) == NULL) {
 238                 cwarn("%s", out);
 239                 goto err;
 240         }
 241         oreg <<= 1;
 242         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 243                 if (fwrite(buf, 1, nr, ofp) != nr) {
 244                         cwarn("%s", out);
 245                         goto err;
 246                 }
 247
 248         if (ferror(ifp))
 249                 error = in;
 250         if (fclose(ifp))
 251                 if (error == NULL)
 252                         error = in;
 253         if (fclose(ofp))
 254                 if (error == NULL)
 255                         error = out;
 256         ifp = NULL;
 257         ofp = NULL;
 258         if (error) {
 259                 cwarn("%s", error);
 260                 goto err;
 261         }
 262
 263         if (isreg && oreg) {
 264                 if (stat(out, &sb)) {
 265                         cwarn("%s", out);
 266                         goto err;
 267                 }
 268
 269                 if (!force && sb.st_size >= isb.st_size) {
 270                         if (verbose)
 271                 (void)printf("%s: file would grow; left unmodified\n", in);
 272                         goto err;
 273                 }
 274
 275                 setfile(out, &isb);
 276
 277                 if (unlink(in))
 278                         cwarn("%s", in);
 279
 280                 if (verbose) {
 281                         (void)printf("%s: ", out);
 282                         if (isb.st_size > sb.st_size)
 283                                 (void)printf("%.0f%% compression\n",
 284                                     ((double)sb.st_size / isb.st_size) * 100.0);
 285                         else
 286                                 (void)printf("%.0f%% expansion\n",
 287                                     ((double)isb.st_size / sb.st_size) * 100.0);
 288                 }
 289         }
 290         return;
 291
 292 err:    if (ofp)
 293                 (void)fclose(ofp);
 294         if (oreg == 2)
 295                 (void)unlink(out);
 296         if (ifp)
 297                 (void)fclose(ifp);
 298 }
 299
 300 void
 301 decompress(const char *in, const char *out, int bits)
 302 {
 303         size_t nr;
 304         struct stat sb;
 305         FILE *ifp, *ofp;
 306         int exists, isreg, oreg;
 307         u_char buf[BUFSIZ];
 308
 309         if (!isstdout) {
 310                 exists = !stat(out, &sb);
 311                 if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
 312                         return;
 313                 oreg = !exists || S_ISREG(sb.st_mode);
 314         } else
 315                 oreg = 0;
 316
 317         ifp = ofp = NULL;
 318         if ((ofp = fopen(out, "w")) == NULL) {
 319                 cwarn("%s", out);
 320                 return;
 321         }
 322
 323         if ((ifp = zopen(in, "r", bits)) == NULL) {
 324                 cwarn("%s", in);
 325                 goto err;
 326         }
 327         if (!isstdin) {
 328                 if (stat(in, &sb)) {
 329                         cwarn("%s", in);
 330                         goto err;
 331                 }
 332                 if (!S_ISREG(sb.st_mode))
 333                         isreg = 0;
 334                 else
 335                         isreg = 1;
 336         } else
 337                 isreg = 0;
 338
 339         oreg <<= 1;
 340         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 341                 if (fwrite(buf, 1, nr, ofp) != nr) {
 342                         cwarn("%s", out);
 343                         goto err;
 344                 }
 345
 346         if (ferror(ifp)) {
 347                 cwarn("%s", in);
 348                 goto err;
 349         }
 350         if (fclose(ifp)) {
 351                 ifp = NULL;
 352                 cwarn("%s", in);
 353                 goto err;
 354         }
 355         ifp = NULL;
 356
 357         if (fclose(ofp)) {
 358                 ofp = NULL;
 359                 cwarn("%s", out);
 360                 goto err;
 361         }
 362
 363         if (isreg && oreg) {
 364                 setfile(out, &sb);
 365
 366                 if (unlink(in))
 367                         cwarn("%s", in);
 368         }
 369         return;
 370
 371 err:    if (ofp)
 372                 (void)fclose(ofp);
 373         if (oreg == 2)
 374                 (void)unlink(out);
 375         if (ifp)
 376                 (void)fclose(ifp);
 377 }
 378
 379 void
 380 setfile(const char *name, struct stat *fs)
 381 {
 382         static struct timeval tv[2];
 383
 384         fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
 385
 386         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 387         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 388         if (utimes(name, tv))
 389                 cwarn("utimes: %s", name);
 390
 391         /*
 392          * Changing the ownership probably won't succeed, unless we're root
 393          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 394          * the mode; current BSD behavior is to remove all setuid bits on
 395          * chown.  If chown fails, lose setuid/setgid bits.
 396          */
 397         if (chown(name, fs->st_uid, fs->st_gid)) {
 398                 if (errno != EPERM)
 399                         cwarn("chown: %s", name);
 400                 fs->st_mode &= ~(S_ISUID|S_ISGID);
 401         }
 402         if (chmod(name, fs->st_mode))
 403                 cwarn("chown: %s", name);
 404
 405         /*
 406          * Restore the file's flags.  However, do this only if the original
 407          * file had any flags set; this avoids a warning on file-systems that
 408          * do not support flags.
 409          */
 410         if (fs->st_flags != 0 && chflags(name, fs->st_flags))
 411                 cwarn("chflags: %s", name);
 412 }
 413
 414 int
 415 permission(const char *fname)
 416 {
 417         int ch, first;
 418
 419         if (!isatty(fileno(stderr)))
 420                 return (0);
 421         (void)fprintf(stderr, "overwrite %s? ", fname);
 422         first = ch = getchar();
 423         while (ch != '\n' && ch != EOF)
 424                 ch = getchar();
 425         return (first == 'y');
 426 }
 427
 428 void
 429 usage(int iscompress)
 430 {
 431         if (iscompress)
 432                 (void)fprintf(stderr,
 433                     "usage: compress [-cdfv] [-b bits] [file ...]\n");
 434         else
 435                 (void)fprintf(stderr,
 436                     "usage: uncompress [-cdfv] [-b bits] [file ...]\n");
 437         exit(1);
 438 }
 439
 440 void
 441 cwarnx(const char *fmt, ...)
 442 {
 443         va_list ap;
 444
 445         va_start(ap, fmt);
 446         vwarnx(fmt, ap);
 447         va_end(ap);
 448         eval = 1;
 449 }
 450
 451 void
 452 cwarn(const char *fmt, ...)
 453 {
 454         va_list ap;
 455
 456         va_start(ap, fmt);
 457         vwarn(fmt, ap);
 458         va_end(ap);
 459         eval = 1;
 460 }