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  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #ifndef lint
  31 static const char copyright[] =
  32 "@(#) Copyright (c) 1992, 1993\n\
  33         The Regents of the University of California.  All rights reserved.\n";
  34 #endif
  35
  36 #if 0
  37 #ifndef lint
  38 static char sccsid[] = "@(#)compress.c  8.2 (Berkeley) 1/7/94";
  39 #endif
  40 #endif
  41
  42 #include <sys/cdefs.h>
  43 __FBSDID("$FreeBSD: src/usr.bin/compress/compress.c,v 1.23 2010/12/11 08:32:16 joel Exp $");
  44
  45 #include <sys/param.h>
  46 #include <sys/stat.h>
  47 #include <sys/time.h>
  48
  49 #include <err.h>
  50 #include <errno.h>
  51 #include <stdarg.h>
  52 #include <stdio.h>
  53 #include <stdlib.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56
  57 #include "zopen.h"
  58
  59 void    compress(const char *, const char *, int);
  60 void    cwarn(const char *, ...) __printflike(1, 2);
  61 void    cwarnx(const char *, ...) __printflike(1, 2);
  62 void    decompress(const char *, const char *, int);
  63 int     permission(const char *);
  64 void    setfile(const char *, struct stat *);
  65 void    usage(int);
  66
  67 int eval, force, verbose, cat;
  68
  69 int
  70 main(int argc, char *argv[])
  71 {
  72         enum {COMPRESS, DECOMPRESS} style;
  73         size_t len;
  74         int bits, ch;
  75         char *p, newname[MAXPATHLEN];
  76
  77         if (argc < 1)
  78                 usage(1);
  79         cat = 0;
  80         if ((p = rindex(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                 cat = 1;
  90                 style = DECOMPRESS;
  91         } else
  92                 errx(1, "unknown program name");
  93
  94         bits = 0;
  95         while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
  96                 switch(ch) {
  97                 case 'b':
  98                         bits = strtol(optarg, &p, 10);
  99                         if (*p)
 100                                 errx(1, "illegal bit count -- %s", optarg);
 101                         break;
 102                 case 'c':
 103                         cat = 1;
 104                         break;
 105                 case 'd':               /* Backward compatible. */
 106                         style = DECOMPRESS;
 107                         break;
 108                 case 'f':
 109                         force = 1;
 110                         break;
 111                 case 'v':
 112                         verbose = 1;
 113                         break;
 114                 case '?':
 115                 default:
 116                         usage(style == COMPRESS);
 117                 }
 118         argc -= optind;
 119         argv += optind;
 120
 121         if (argc == 0) {
 122                 cat = 1;
 123                 switch(style) {
 124                 case COMPRESS:
 125                         (void)compress("/dev/stdin", "/dev/stdout", bits);
 126                         break;
 127                 case DECOMPRESS:
 128                         (void)decompress("/dev/stdin", "/dev/stdout", bits);
 129                         break;
 130                 }
 131                 exit (eval);
 132         }
 133
 134         if (cat == 1 && argc > 1)
 135                 errx(1, "the -c option permits only a single file argument");
 136
 137         for (; *argv; ++argv)
 138                 switch(style) {
 139                 case COMPRESS:
 140                         if (strcmp(*argv, "-") == 0) {
 141                                 cat = 1;
 142                                 compress("/dev/stdin", "/dev/stdout", bits);
 143                                 break;
 144                         } else if (cat) {
 145                                 compress(*argv, "/dev/stdout", bits);
 146                                 break;
 147                         }
 148                         if ((p = rindex(*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                         if (strcmp(*argv, "-") == 0) {
 167                                 cat = 1;
 168                                 decompress("/dev/stdin", "/dev/stdout", bits);
 169                                 break;
 170                         }
 171                         len = strlen(*argv);
 172                         if ((p = rindex(*argv, '.')) == NULL ||
 173                             strcmp(p, ".Z")) {
 174                                 if (len > sizeof(newname) - 3) {
 175                                         cwarnx("%s: name too long", *argv);
 176                                         break;
 177                                 }
 178                                 memmove(newname, *argv, len);
 179                                 newname[len] = '.';
 180                                 newname[len + 1] = 'Z';
 181                                 newname[len + 2] = '\0';
 182                                 decompress(newname,
 183                                     cat ? "/dev/stdout" : *argv, bits);
 184                         } else {
 185                                 if (len - 2 > sizeof(newname) - 1) {
 186                                         cwarnx("%s: name too long", *argv);
 187                                         break;
 188                                 }
 189                                 memmove(newname, *argv, len - 2);
 190                                 newname[len - 2] = '\0';
 191                                 decompress(*argv,
 192                                     cat ? "/dev/stdout" : newname, bits);
 193                         }
 194                         break;
 195                 }
 196         exit (eval);
 197 }
 198
 199 void
 200 compress(const char *in, const char *out, int bits)
 201 {
 202         size_t nr;
 203         struct stat isb, sb;
 204         FILE *ifp = NULL, *ofp = NULL;
 205         int exists, isreg, oreg;
 206         u_char buf[1024];
 207
 208         exists = !stat(out, &sb);
 209         if (!force && exists && S_ISREG(sb.st_mode) && !cat && !permission(out)) {
 210                 cwarnx("%s already exists", out);
 211                 return;
 212         }
 213         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 214
 215         if ((ifp = fopen(in, "r")) == NULL) {
 216                 cwarn("%s", in);
 217                 return;
 218         }
 219         if (stat(in, &isb)) {           /* DON'T FSTAT! */
 220                 cwarn("%s", in);
 221                 goto err;
 222         }
 223         if (!S_ISREG(isb.st_mode))
 224                 isreg = 0;
 225
 226         if ((ofp = zopen(out, "w", bits)) == NULL) {
 227                 cwarn("%s", out);
 228                 goto err;
 229         }
 230         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 231                 if (fwrite(buf, 1, nr, ofp) != nr) {
 232                         cwarn("%s", out);
 233                         goto err;
 234                 }
 235
 236         if (ferror(ifp) || fclose(ifp)) {
 237                 cwarn("%s", in);
 238                 goto err;
 239         }
 240         ifp = NULL;
 241
 242         if (fclose(ofp)) {
 243                 cwarn("%s", out);
 244                 goto err;
 245         }
 246         ofp = NULL;
 247
 248         if (!cat && isreg) {
 249                 if (stat(out, &sb)) {
 250                         cwarn("%s", out);
 251                         goto err;
 252                 }
 253
 254                 if (!force && sb.st_size >= isb.st_size) {
 255                         if (verbose)
 256                 (void)fprintf(stderr, "%s: file would grow; left unmodified\n",
 257                     in);
 258                         eval = 2;
 259                         if (unlink(out))
 260                                 cwarn("%s", out);
 261                         goto err;
 262                 }
 263
 264                 setfile(out, &isb);
 265
 266                 if (unlink(in))
 267                         cwarn("%s", in);
 268
 269                 if (verbose) {
 270                         (void)fprintf(stderr, "%s: ", out);
 271                         if (isb.st_size > sb.st_size)
 272                                 (void)fprintf(stderr, "%.0f%% compression\n",
 273                                     ((float)sb.st_size / isb.st_size) * 100.0);
 274                         else
 275                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 276                                     ((float)isb.st_size / sb.st_size) * 100.0);
 277                 }
 278         }
 279         return;
 280
 281 err:    if (ofp) {
 282                 if (!cat && oreg)
 283                         (void)unlink(out);
 284                 (void)fclose(ofp);
 285         }
 286         if (ifp)
 287                 (void)fclose(ifp);
 288 }
 289
 290 void
 291 decompress(const char *in, const char *out, int bits)
 292 {
 293         size_t nr;
 294         struct stat sb;
 295         FILE *ifp, *ofp;
 296         int exists, isreg, oreg;
 297         u_char buf[1024];
 298
 299         exists = !stat(out, &sb);
 300         if (!force && exists && S_ISREG(sb.st_mode) && !cat && !permission(out)) {
 301                 cwarnx("%s already exists", out);
 302                 return;
 303         }
 304         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 305
 306         ofp = NULL;
 307         if ((ifp = zopen(in, "r", bits)) == NULL) {
 308                 cwarn("%s", in);
 309                 return;
 310         }
 311         if (stat(in, &sb)) {
 312                 cwarn("%s", in);
 313                 goto err;
 314         }
 315         if (!S_ISREG(sb.st_mode))
 316                 isreg = 0;
 317
 318         /*
 319          * Try to read the first few uncompressed bytes from the input file
 320          * before blindly truncating the output file.
 321          */
 322         if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
 323                 cwarn("%s", in);
 324                 (void)fclose(ifp);
 325                 return;
 326         }
 327         if ((ofp = fopen(out, "w")) == NULL ||
 328             (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
 329                 cwarn("%s", out);
 330                 (void)fclose(ifp);
 331                 return;
 332         }
 333
 334         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 335                 if (fwrite(buf, 1, nr, ofp) != nr) {
 336                         cwarn("%s", out);
 337                         goto err;
 338                 }
 339
 340         if (ferror(ifp) || fclose(ifp)) {
 341                 cwarn("%s", in);
 342                 goto err;
 343         }
 344         ifp = NULL;
 345
 346         if (fclose(ofp)) {
 347                 cwarn("%s", out);
 348                 goto err;
 349         }
 350
 351         if (!cat && isreg) {
 352                 setfile(out, &sb);
 353
 354                 if (unlink(in))
 355                         cwarn("%s", in);
 356                 if (verbose) {
 357                         struct stat isb = sb;
 358                         stat(out, &sb);
 359                         (void)fprintf(stderr, "%s: ", out);
 360                         if (isb.st_size > sb.st_size)
 361                                 (void)fprintf(stderr, "%.0f%% compression\n",
 362                                     ((float)sb.st_size / isb.st_size) * 100.0);
 363                         else
 364                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 365                                     ((float)isb.st_size / sb.st_size) * 100.0);
 366                 }
 367         }
 368         return;
 369
 370 err:    if (ofp) {
 371                 if (!cat && oreg)
 372                         (void)unlink(out);
 373                 (void)fclose(ofp);
 374         }
 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) && errno != ENOTSUP)
 403                 cwarn("chmod: %s", name);
 404
 405         if (chflags(name, fs->st_flags) && errno != ENOTSUP)
 406                 cwarn("chflags: %s", name);
 407 }
 408
 409 int
 410 permission(const char *fname)
 411 {
 412         int ch, first;
 413
 414         if (!isatty(fileno(stderr)))
 415                 return (0);
 416         (void)fprintf(stderr, "overwrite %s? ", fname);
 417         first = ch = getchar();
 418         while (ch != '\n' && ch != EOF)
 419                 ch = getchar();
 420         return (first == 'y');
 421 }
 422
 423 void
 424 usage(int iscompress)
 425 {
 426         if (iscompress)
 427                 (void)fprintf(stderr,
 428                     "usage: compress [-cfv] [-b bits] [file ...]\n");
 429         else
 430                 (void)fprintf(stderr,
 431                     "usage: uncompress [-cfv] [-b bits] [file ...]\n");
 432         exit(1);
 433 }
 434
 435 void
 436 cwarnx(const char *fmt, ...)
 437 {
 438         va_list ap;
 439
 440         va_start(ap, fmt);
 441         vwarnx(fmt, ap);
 442         va_end(ap);
 443         eval = 1;
 444 }
 445
 446 void
 447 cwarn(const char *fmt, ...)
 448 {
 449         va_list ap;
 450
 451         va_start(ap, fmt);
 452         vwarn(fmt, ap);
 453         va_end(ap);
 454         eval = 1;
 455 }