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, *ofp;
 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         ifp = ofp = NULL;
 216         if ((ifp = fopen(in, "r")) == NULL) {
 217                 cwarn("%s", in);
 218                 return;
 219         }
 220         if (stat(in, &isb)) {           /* DON'T FSTAT! */
 221                 cwarn("%s", in);
 222                 goto err;
 223         }
 224         if (!S_ISREG(isb.st_mode))
 225                 isreg = 0;
 226
 227         if ((ofp = zopen(out, "w", bits)) == NULL) {
 228                 cwarn("%s", out);
 229                 goto err;
 230         }
 231         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 232                 if (fwrite(buf, 1, nr, ofp) != nr) {
 233                         cwarn("%s", out);
 234                         goto err;
 235                 }
 236
 237         if (ferror(ifp) || fclose(ifp)) {
 238                 cwarn("%s", in);
 239                 goto err;
 240         }
 241         ifp = NULL;
 242
 243         if (fclose(ofp)) {
 244                 cwarn("%s", out);
 245                 goto err;
 246         }
 247         ofp = NULL;
 248
 249         if (!cat && isreg) {
 250                 if (stat(out, &sb)) {
 251                         cwarn("%s", out);
 252                         goto err;
 253                 }
 254
 255                 if (!force && sb.st_size >= isb.st_size) {
 256                         if (verbose)
 257                 (void)fprintf(stderr, "%s: file would grow; left unmodified\n",
 258                     in);
 259                         eval = 2;
 260                         if (unlink(out))
 261                                 cwarn("%s", out);
 262                         goto err;
 263                 }
 264
 265                 setfile(out, &isb);
 266
 267                 if (unlink(in))
 268                         cwarn("%s", in);
 269
 270                 if (verbose) {
 271                         (void)fprintf(stderr, "%s: ", out);
 272                         if (isb.st_size > sb.st_size)
 273                                 (void)fprintf(stderr, "%.0f%% compression\n",
 274                                     ((float)sb.st_size / isb.st_size) * 100.0);
 275                         else
 276                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 277                                     ((float)isb.st_size / sb.st_size) * 100.0);
 278                 }
 279         }
 280         return;
 281
 282 err:    if (ofp) {
 283                 if (!cat && oreg)
 284                         (void)unlink(out);
 285                 (void)fclose(ofp);
 286         }
 287         if (ifp)
 288                 (void)fclose(ifp);
 289 }
 290
 291 void
 292 decompress(const char *in, const char *out, int bits)
 293 {
 294         size_t nr;
 295         struct stat sb;
 296         FILE *ifp, *ofp;
 297         int exists, isreg, oreg;
 298         u_char buf[1024];
 299
 300         exists = !stat(out, &sb);
 301         if (!force && exists && S_ISREG(sb.st_mode) && !cat && !permission(out)) {
 302                 cwarnx("%s already exists", out);
 303                 return;
 304         }
 305         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 306
 307         ifp = ofp = NULL;
 308         if ((ifp = zopen(in, "r", bits)) == NULL) {
 309                 cwarn("%s", in);
 310                 return;
 311         }
 312         if (stat(in, &sb)) {
 313                 cwarn("%s", in);
 314                 goto err;
 315         }
 316         if (!S_ISREG(sb.st_mode))
 317                 isreg = 0;
 318
 319         /*
 320          * Try to read the first few uncompressed bytes from the input file
 321          * before blindly truncating the output file.
 322          */
 323         if ((nr = fread(buf, 1, sizeof(buf), ifp)) == 0) {
 324                 cwarn("%s", in);
 325                 (void)fclose(ifp);
 326                 return;
 327         }
 328         if ((ofp = fopen(out, "w")) == NULL ||
 329             (nr != 0 && fwrite(buf, 1, nr, ofp) != nr)) {
 330                 cwarn("%s", out);
 331                 (void)fclose(ifp);
 332                 return;
 333         }
 334
 335         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 336                 if (fwrite(buf, 1, nr, ofp) != nr) {
 337                         cwarn("%s", out);
 338                         goto err;
 339                 }
 340
 341         if (ferror(ifp) || fclose(ifp)) {
 342                 cwarn("%s", in);
 343                 goto err;
 344         }
 345         ifp = NULL;
 346
 347         if (fclose(ofp)) {
 348                 cwarn("%s", out);
 349                 goto err;
 350         }
 351
 352         if (!cat && isreg) {
 353                 setfile(out, &sb);
 354
 355                 if (unlink(in))
 356                         cwarn("%s", in);
 357                 if (verbose) {
 358                         struct stat isb = sb;
 359                         stat(out, &sb);
 360                         (void)fprintf(stderr, "%s: ", out);
 361                         if (isb.st_size > sb.st_size)
 362                                 (void)fprintf(stderr, "%.0f%% compression\n",
 363                                     ((float)sb.st_size / isb.st_size) * 100.0);
 364                         else
 365                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 366                                     ((float)isb.st_size / sb.st_size) * 100.0);
 367                 }
 368         }
 369         return;
 370
 371 err:    if (ofp) {
 372                 if (!cat && oreg)
 373                         (void)unlink(out);
 374                 (void)fclose(ofp);
 375         }
 376         if (ifp)
 377                 (void)fclose(ifp);
 378 }
 379
 380 void
 381 setfile(const char *name, struct stat *fs)
 382 {
 383         static struct timeval tv[2];
 384
 385         fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
 386
 387         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 388         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 389         if (utimes(name, tv))
 390                 cwarn("utimes: %s", name);
 391
 392         /*
 393          * Changing the ownership probably won't succeed, unless we're root
 394          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 395          * the mode; current BSD behavior is to remove all setuid bits on
 396          * chown.  If chown fails, lose setuid/setgid bits.
 397          */
 398         if (chown(name, fs->st_uid, fs->st_gid)) {
 399                 if (errno != EPERM)
 400                         cwarn("chown: %s", name);
 401                 fs->st_mode &= ~(S_ISUID|S_ISGID);
 402         }
 403         if (chmod(name, fs->st_mode) && errno != ENOTSUP)
 404                 cwarn("chmod: %s", name);
 405
 406         if (chflags(name, fs->st_flags) && errno != ENOTSUP)
 407                 cwarn("chflags: %s", name);
 408 }
 409
 410 int
 411 permission(const char *fname)
 412 {
 413         int ch, first;
 414
 415         if (!isatty(fileno(stderr)))
 416                 return (0);
 417         (void)fprintf(stderr, "overwrite %s? ", fname);
 418         first = ch = getchar();
 419         while (ch != '\n' && ch != EOF)
 420                 ch = getchar();
 421         return (first == 'y');
 422 }
 423
 424 void
 425 usage(int iscompress)
 426 {
 427         if (iscompress)
 428                 (void)fprintf(stderr,
 429                     "usage: compress [-cfv] [-b bits] [file ...]\n");
 430         else
 431                 (void)fprintf(stderr,
 432                     "usage: uncompress [-cfv] [-b bits] [file ...]\n");
 433         exit(1);
 434 }
 435
 436 void
 437 cwarnx(const char *fmt, ...)
 438 {
 439         va_list ap;
 440
 441         va_start(ap, fmt);
 442         vwarnx(fmt, ap);
 443         va_end(ap);
 444         eval = 1;
 445 }
 446
 447 void
 448 cwarn(const char *fmt, ...)
 449 {
 450         va_list ap;
 451
 452         va_start(ap, fmt);
 453         vwarn(fmt, ap);
 454         va_end(ap);
 455         eval = 1;
 456 }