usr.bin/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. 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  * @(#) Copyright (c) 1992, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)compress.c       8.2 (Berkeley) 1/7/94
  31  * $FreeBSD: src/usr.bin/compress/compress.c,v 1.7.6.5 2002/07/16 00:56:04 tjr Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/stat.h>
  36 #include <sys/time.h>
  37
  38 #include <err.h>
  39 #include <errno.h>
  40 #include <stdarg.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <string.h>
  44 #include <unistd.h>
  45
  46 #include "zopen.h"
  47
  48 static void     compress(const char *, const char *, int);
  49 static void     cwarn(const char *, ...) __printflike(1, 2);
  50 static void     cwarnx(const char *, ...) __printflike(1, 2);
  51 static void     decompress(const char *, const char *, int);
  52 static int      permission(const char *);
  53 static void     setfile(const char *, struct stat *);
  54 static void     usage(int) __dead2;
  55
  56 static int eval, force, verbose;
  57
  58 int
  59 main(int argc, char **argv)
  60 {
  61         enum {COMPRESS, DECOMPRESS} style;
  62         size_t len;
  63         int bits, cat, ch;
  64         char *p, newname[MAXPATHLEN];
  65
  66         cat = 0;
  67         if ((p = strrchr(argv[0], '/')) == NULL)
  68                 p = argv[0];
  69         else
  70                 ++p;
  71         if (!strcmp(p, "uncompress"))
  72                 style = DECOMPRESS;
  73         else if (!strcmp(p, "compress"))
  74                 style = COMPRESS;
  75         else if (!strcmp(p, "zcat")) {
  76                 cat = 1;
  77                 style = DECOMPRESS;
  78         } else
  79                 errx(1, "unknown program name");
  80
  81         bits = 0;
  82         while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
  83                 switch(ch) {
  84                 case 'b':
  85                         bits = strtol(optarg, &p, 10);
  86                         if (*p)
  87                                 errx(1, "illegal bit count -- %s", optarg);
  88                         break;
  89                 case 'c':
  90                         cat = 1;
  91                         break;
  92                 case 'd':               /* Backward compatible. */
  93                         style = DECOMPRESS;
  94                         break;
  95                 case 'f':
  96                         force = 1;
  97                         break;
  98                 case 'v':
  99                         verbose = 1;
 100                         break;
 101                 case '?':
 102                 default:
 103                         usage(style == COMPRESS);
 104                 }
 105         argc -= optind;
 106         argv += optind;
 107
 108         if (argc == 0) {
 109                 switch(style) {
 110                 case COMPRESS:
 111                         (void)compress("/dev/stdin", "/dev/stdout", bits);
 112                         break;
 113                 case DECOMPRESS:
 114                         (void)decompress("/dev/stdin", "/dev/stdout", bits);
 115                         break;
 116                 }
 117                 exit (eval);
 118         }
 119
 120         if (cat == 1 && argc > 1)
 121                 errx(1, "the -c option permits only a single file argument");
 122
 123         for (; *argv; ++argv)
 124                 switch(style) {
 125                 case COMPRESS:
 126                         if (strcmp(*argv, "-") == 0) {
 127                                 compress("/dev/stdin", "/dev/stdout", bits);
 128                                 break;
 129                         } else if (cat) {
 130                                 compress(*argv, "/dev/stdout", bits);
 131                                 break;
 132                         }
 133                         if ((p = strrchr(*argv, '.')) != NULL &&
 134                             !strcmp(p, ".Z")) {
 135                                 cwarnx("%s: name already has trailing .Z",
 136                                     *argv);
 137                                 break;
 138                         }
 139                         len = strlen(*argv);
 140                         if (len > sizeof(newname) - 3) {
 141                                 cwarnx("%s: name too long", *argv);
 142                                 break;
 143                         }
 144                         memmove(newname, *argv, len);
 145                         newname[len] = '.';
 146                         newname[len + 1] = 'Z';
 147                         newname[len + 2] = '\0';
 148                         compress(*argv, newname, bits);
 149                         break;
 150                 case DECOMPRESS:
 151                         if (strcmp(*argv, "-") == 0) {
 152                                 decompress("/dev/stdin", "/dev/stdout", bits);
 153                                 break;
 154                         }
 155                         len = strlen(*argv);
 156                         if ((p = strrchr(*argv, '.')) == NULL ||
 157                             strcmp(p, ".Z")) {
 158                                 if (len > sizeof(newname) - 3) {
 159                                         cwarnx("%s: name too long", *argv);
 160                                         break;
 161                                 }
 162                                 memmove(newname, *argv, len);
 163                                 newname[len] = '.';
 164                                 newname[len + 1] = 'Z';
 165                                 newname[len + 2] = '\0';
 166                                 decompress(newname,
 167                                     cat ? "/dev/stdout" : *argv, bits);
 168                         } else {
 169                                 if (len - 2 > sizeof(newname) - 1) {
 170                                         cwarnx("%s: name too long", *argv);
 171                                         break;
 172                                 }
 173                                 memmove(newname, *argv, len - 2);
 174                                 newname[len - 2] = '\0';
 175                                 decompress(*argv,
 176                                     cat ? "/dev/stdout" : newname, bits);
 177                         }
 178                         break;
 179                 }
 180         exit (eval);
 181 }
 182
 183 static void
 184 compress(const char *in, const char *out, int bits)
 185 {
 186         size_t nr;
 187         struct stat isb, sb;
 188         FILE *ifp, *ofp;
 189         int exists, isreg, oreg;
 190         u_char buf[1024];
 191
 192         exists = !stat(out, &sb);
 193         if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
 194                 return;
 195         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 196
 197         ifp = ofp = NULL;
 198         if ((ifp = fopen(in, "r")) == NULL) {
 199                 cwarn("%s", in);
 200                 return;
 201         }
 202         if (stat(in, &isb)) {           /* DON'T FSTAT! */
 203                 cwarn("%s", in);
 204                 goto err;
 205         }
 206         if (!S_ISREG(isb.st_mode))
 207                 isreg = 0;
 208
 209         if ((ofp = zopen(out, "w", bits)) == NULL) {
 210                 cwarn("%s", out);
 211                 goto err;
 212         }
 213         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 214                 if (fwrite(buf, 1, nr, ofp) != nr) {
 215                         cwarn("%s", out);
 216                         goto err;
 217                 }
 218
 219         if (ferror(ifp) || fclose(ifp)) {
 220                 cwarn("%s", in);
 221                 goto err;
 222         }
 223         ifp = NULL;
 224
 225         if (fclose(ofp)) {
 226                 cwarn("%s", out);
 227                 goto err;
 228         }
 229         ofp = NULL;
 230
 231         if (isreg) {
 232                 if (stat(out, &sb)) {
 233                         cwarn("%s", out);
 234                         goto err;
 235                 }
 236
 237                 if (!force && sb.st_size >= isb.st_size) {
 238                         if (verbose)
 239                 (void)fprintf(stderr, "%s: file would grow; left unmodified\n",
 240                     in);
 241                         eval = 2;
 242                         if (unlink(out))
 243                                 cwarn("%s", out);
 244                         goto err;
 245                 }
 246
 247                 setfile(out, &isb);
 248
 249                 if (unlink(in))
 250                         cwarn("%s", in);
 251
 252                 if (verbose) {
 253                         (void)fprintf(stderr, "%s: ", out);
 254                         if (isb.st_size > sb.st_size)
 255                                 (void)fprintf(stderr, "%.0f%% compression\n",
 256                                     ((float)sb.st_size / isb.st_size) * 100.0);
 257                         else
 258                                 (void)fprintf(stderr, "%.0f%% expansion\n",
 259                                     ((float)isb.st_size / sb.st_size) * 100.0);
 260                 }
 261         }
 262         return;
 263
 264 err:    if (ofp) {
 265                 if (oreg)
 266                         (void)unlink(out);
 267                 (void)fclose(ofp);
 268         }
 269         if (ifp)
 270                 (void)fclose(ifp);
 271 }
 272
 273 static void
 274 decompress(const char *in, const char *out, int bits)
 275 {
 276         size_t nr;
 277         struct stat sb;
 278         FILE *ifp, *ofp;
 279         int exists, isreg, oreg;
 280         u_char buf[1024];
 281
 282         exists = !stat(out, &sb);
 283         if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
 284                 return;
 285         isreg = oreg = !exists || S_ISREG(sb.st_mode);
 286
 287         ifp = ofp = NULL;
 288         if ((ofp = fopen(out, "w")) == NULL) {
 289                 cwarn("%s", out);
 290                 return;
 291         }
 292
 293         if ((ifp = zopen(in, "r", bits)) == NULL) {
 294                 cwarn("%s", in);
 295                 goto err;
 296         }
 297         if (stat(in, &sb)) {
 298                 cwarn("%s", in);
 299                 goto err;
 300         }
 301         if (!S_ISREG(sb.st_mode))
 302                 isreg = 0;
 303
 304         while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
 305                 if (fwrite(buf, 1, nr, ofp) != nr) {
 306                         cwarn("%s", out);
 307                         goto err;
 308                 }
 309
 310         if (ferror(ifp) || fclose(ifp)) {
 311                 cwarn("%s", in);
 312                 goto err;
 313         }
 314         ifp = NULL;
 315
 316         if (fclose(ofp)) {
 317                 cwarn("%s", out);
 318                 goto err;
 319         }
 320
 321         if (isreg) {
 322                 setfile(out, &sb);
 323
 324                 if (unlink(in))
 325                         cwarn("%s", in);
 326         }
 327         return;
 328
 329 err:    if (ofp) {
 330                 if (oreg)
 331                         (void)unlink(out);
 332                 (void)fclose(ofp);
 333         }
 334         if (ifp)
 335                 (void)fclose(ifp);
 336 }
 337
 338 static void
 339 setfile(const char *name, struct stat *fs)
 340 {
 341         static struct timeval tv[2];
 342
 343         fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
 344
 345         TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
 346         TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
 347         if (utimes(name, tv))
 348                 cwarn("utimes: %s", name);
 349
 350         /*
 351          * Changing the ownership probably won't succeed, unless we're root
 352          * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
 353          * the mode; current BSD behavior is to remove all setuid bits on
 354          * chown.  If chown fails, lose setuid/setgid bits.
 355          */
 356         if (chown(name, fs->st_uid, fs->st_gid)) {
 357                 if (errno != EPERM)
 358                         cwarn("chown: %s", name);
 359                 fs->st_mode &= ~(S_ISUID|S_ISGID);
 360         }
 361         if (chmod(name, fs->st_mode) && errno != EOPNOTSUPP)
 362                 cwarn("chmod: %s", name);
 363
 364         if (chflags(name, fs->st_flags) && errno != EOPNOTSUPP)
 365                 cwarn("chflags: %s", name);
 366 }
 367
 368 static int
 369 permission(const char *fname)
 370 {
 371         int ch, first;
 372
 373         if (!isatty(fileno(stderr)))
 374                 return (0);
 375         (void)fprintf(stderr, "overwrite %s? ", fname);
 376         first = ch = getchar();
 377         while (ch != '\n' && ch != EOF)
 378                 ch = getchar();
 379         return (first == 'y');
 380 }
 381
 382 static void
 383 usage(int iscompress)
 384 {
 385         if (iscompress)
 386                 (void)fprintf(stderr,
 387                     "usage: compress [-cfv] [-b bits] [file ...]\n");
 388         else
 389                 (void)fprintf(stderr,
 390                     "usage: uncompress [-c] [-b bits] [file ...]\n");
 391         exit(1);
 392 }
 393
 394 static void
 395 cwarnx(const char *fmt, ...)
 396 {
 397         va_list ap;
 398
 399         va_start(ap, fmt);
 400         vwarnx(fmt, ap);
 401         va_end(ap);
 402         eval = 1;
 403 }
 404
 405 static void
 406 cwarn(const char *fmt, ...)
 407 {
 408         va_list ap;
 409
 410         va_start(ap, fmt);
 411         vwarn(fmt, ap);
 412         va_end(ap);
 413         eval = 1;
 414 }