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compress.c revision 1.17 
      1 /*	$NetBSD: compress.c,v 1.17 1998/10/08 01:56:28 wsanchez 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  */
     35 
     36 #include <sys/cdefs.h>
     37 #ifndef lint
     38 __COPYRIGHT("@(#) Copyright (c) 1992, 1993\n\
     39 	The Regents of the University of California.  All rights reserved.\n");
     40 #endif /* not lint */
     41 
     42 #ifndef lint
     43 #if 0
     44 static char sccsid[] = "@(#)compress.c	8.2 (Berkeley) 1/7/94";
     45 #else
     46 __RCSID("$NetBSD: compress.c,v 1.17 1998/10/08 01:56:28 wsanchez Exp $");
     47 #endif
     48 #endif /* not lint */
     49 
     50 #include <sys/param.h>
     51 #include <sys/time.h>
     52 #include <sys/stat.h>
     53 
     54 #include <err.h>
     55 #include <errno.h>
     56 #include <stdio.h>
     57 #include <stdlib.h>
     58 #include <string.h>
     59 #include <unistd.h>
     60 
     61 #ifdef __STDC__
     62 #include <stdarg.h>
     63 #else
     64 #include <varargs.h>
     65 #endif
     66 
     67 void	compress __P((char *, char *, int));
     68 void	cwarn __P((const char *, ...));
     69 void	cwarnx __P((const char *, ...));
     70 void	decompress __P((char *, char *, int));
     71 int	permission __P((char *));
     72 void	setfile __P((char *, struct stat *));
     73 void	usage __P((int));
     74 
     75 int	main __P((int, char *[]));
     76 extern FILE *zopen __P((const char *fname, const char *mode, int bits));
     77 
     78 int eval, force, verbose;
     79 int isstdout, isstdin;
     80 
     81 int
     82 main(argc, argv)
     83 	int argc;
     84 	char *argv[];
     85 {
     86         enum {COMPRESS, DECOMPRESS} style = COMPRESS;
     87 	size_t len;
     88 	int bits, cat, ch;
     89 	char *p, newname[MAXPATHLEN];
     90 
     91 	if ((p = strrchr(argv[0], '/')) == NULL)
     92 		p = argv[0];
     93 	else
     94 		++p;
     95 	if (!strcmp(p, "uncompress"))
     96 		style = DECOMPRESS;
     97         else if (!strcmp(p, "compress"))
     98                 style = COMPRESS;
     99         else if (!strcmp(p, "zcat")) {
    100                 style = DECOMPRESS;
    101                 cat = 1;
    102         }
    103 	else
    104 		errx(1, "unknown program name");
    105 
    106 	bits = cat = 0;
    107 	while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
    108 		switch(ch) {
    109 		case 'b':
    110 			bits = strtol(optarg, &p, 10);
    111 			if (*p)
    112 				errx(1, "illegal bit count -- %s", optarg);
    113 			break;
    114 		case 'c':
    115 			cat = 1;
    116 			break;
    117 		case 'd':		/* Backward compatible. */
    118 			style = DECOMPRESS;
    119 			break;
    120 		case 'f':
    121 			force = 1;
    122 			break;
    123 		case 'v':
    124 			verbose = 1;
    125 			break;
    126 		case '?':
    127 		default:
    128 			usage(style == COMPRESS);
    129 		}
    130 	argc -= optind;
    131 	argv += optind;
    132 
    133 	if (argc == 0) {
    134 		switch(style) {
    135 		case COMPRESS:
    136 			isstdout = 1;
    137 			isstdin = 1;
    138 			(void)compress("/dev/stdin", "/dev/stdout", bits);
    139 			break;
    140 		case DECOMPRESS:
    141 			isstdout = 1;
    142 			isstdin = 1;
    143 			(void)decompress("/dev/stdin", "/dev/stdout", bits);
    144 			break;
    145 		}
    146 		exit (eval);
    147 	}
    148 
    149 	if (cat == 1 && argc > 1)
    150 		errx(1, "the -c option permits only a single file argument");
    151 
    152 	for (; *argv; ++argv) {
    153 		isstdout = 0;
    154 		switch(style) {
    155 		case COMPRESS:
    156 			if (cat) {
    157 				isstdout = 1;
    158 				compress(*argv, "/dev/stdout", bits);
    159 				break;
    160 			}
    161 			if ((p = strrchr(*argv, '.')) != NULL &&
    162 			    !strcmp(p, ".Z")) {
    163 				cwarnx("%s: name already has trailing .Z",
    164 				    *argv);
    165 				break;
    166 			}
    167 			len = strlen(*argv);
    168 			if (len > sizeof(newname) - 3) {
    169 				cwarnx("%s: name too long", *argv);
    170 				break;
    171 			}
    172 			memmove(newname, *argv, len);
    173 			newname[len] = '.';
    174 			newname[len + 1] = 'Z';
    175 			newname[len + 2] = '\0';
    176 			compress(*argv, newname, bits);
    177 			break;
    178 		case DECOMPRESS:
    179 			len = strlen(*argv);
    180 			if ((p = strrchr(*argv, '.')) == NULL ||
    181 			    strcmp(p, ".Z")) {
    182 				if (len > sizeof(newname) - 3) {
    183 					cwarnx("%s: name too long", *argv);
    184 					break;
    185 				}
    186 				memmove(newname, *argv, len);
    187 				newname[len] = '.';
    188 				newname[len + 1] = 'Z';
    189 				newname[len + 2] = '\0';
    190 				decompress(newname,
    191 				    cat ? "/dev/stdout" : *argv, bits);
    192 				if (cat)
    193 					isstdout = 1;
    194 			} else {
    195 				if (len - 2 > sizeof(newname) - 1) {
    196 					cwarnx("%s: name too long", *argv);
    197 					break;
    198 				}
    199 				memmove(newname, *argv, len - 2);
    200 				newname[len - 2] = '\0';
    201 				decompress(*argv,
    202 				    cat ? "/dev/stdout" : newname, bits);
    203 				if (cat)
    204 					isstdout = 1;
    205 			}
    206 			break;
    207 		}
    208 	}
    209 	exit (eval);
    210 }
    211 
    212 void
    213 compress(in, out, bits)
    214 	char *in, *out;
    215 	int bits;
    216 {
    217 	int nr;
    218 	struct stat isb, sb;
    219 	FILE *ifp, *ofp;
    220 	int exists, isreg, oreg;
    221 	u_char buf[BUFSIZ];
    222 
    223 	if (!isstdout) {
    224 		exists = !stat(out, &sb);
    225 		if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    226 			return;
    227 		oreg = !exists || S_ISREG(sb.st_mode);
    228 	} else
    229 		oreg = 0;
    230 
    231 	ifp = ofp = NULL;
    232 	if ((ifp = fopen(in, "r")) == NULL) {
    233 		cwarn("%s", in);
    234 		return;
    235 	}
    236 
    237 	if (!isstdin) {
    238 		if (stat(in, &isb)) {		/* DON'T FSTAT! */
    239 			cwarn("%s", in);
    240 			goto err;
    241 		}
    242 		if (!S_ISREG(isb.st_mode))
    243 			isreg = 0;
    244 		else
    245 			isreg = 1;
    246 	} else
    247 		isreg = 0;
    248 
    249 	if ((ofp = zopen(out, "w", bits)) == NULL) {
    250 		cwarn("%s", out);
    251 		goto err;
    252 	}
    253 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    254 		if (fwrite(buf, 1, nr, ofp) != nr) {
    255 			cwarn("%s", out);
    256 			goto err;
    257 		}
    258 
    259 	if (ferror(ifp) || fclose(ifp)) {
    260 		cwarn("%s", in);
    261 		goto err;
    262 	}
    263 	ifp = NULL;
    264 
    265 	if (fclose(ofp)) {
    266 		cwarn("%s", out);
    267 		goto err;
    268 	}
    269 	ofp = NULL;
    270 
    271 	if (isreg && oreg) {
    272 		if (stat(out, &sb)) {
    273 			cwarn("%s", out);
    274 			goto err;
    275 		}
    276 
    277 		if (!force && sb.st_size >= isb.st_size) {
    278 			if (verbose)
    279 		(void)printf("%s: file would grow; left unmodified\n", in);
    280 			if (unlink(out))
    281 				cwarn("%s", out);
    282 			goto err;
    283 		}
    284 
    285 		setfile(out, &isb);
    286 
    287 		if (unlink(in))
    288 			cwarn("%s", in);
    289 
    290 		if (verbose) {
    291 			(void)printf("%s: ", out);
    292 			if (isb.st_size > sb.st_size)
    293 				(void)printf("%.0f%% compression\n",
    294 				    ((double)sb.st_size / isb.st_size) * 100.0);
    295 			else
    296 				(void)printf("%.0f%% expansion\n",
    297 				    ((double)isb.st_size / sb.st_size) * 100.0);
    298 		}
    299 	}
    300 	return;
    301 
    302 err:	if (ofp) {
    303 		if (oreg)
    304 			(void)unlink(out);
    305 		(void)fclose(ofp);
    306 	}
    307 	if (ifp)
    308 		(void)fclose(ifp);
    309 }
    310 
    311 void
    312 decompress(in, out, bits)
    313 	char *in, *out;
    314 	int bits;
    315 {
    316 	int nr;
    317 	struct stat sb;
    318 	FILE *ifp, *ofp;
    319 	int exists, isreg, oreg;
    320 	u_char buf[BUFSIZ];
    321 
    322 	if (!isstdout) {
    323 		exists = !stat(out, &sb);
    324 		if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    325 			return;
    326 		oreg = !exists || S_ISREG(sb.st_mode);
    327 	} else
    328 		oreg = 0;
    329 
    330 	ifp = ofp = NULL;
    331 	if ((ofp = fopen(out, "w")) == NULL) {
    332 		cwarn("%s", out);
    333 		return;
    334 	}
    335 
    336 	if ((ifp = zopen(in, "r", bits)) == NULL) {
    337 		cwarn("%s", in);
    338 		goto err;
    339 	}
    340 	if (!isstdin) {
    341 		if (stat(in, &sb)) {
    342 			cwarn("%s", in);
    343 			goto err;
    344 		}
    345 		if (!S_ISREG(sb.st_mode))
    346 			isreg = 0;
    347 		else
    348 			isreg = 1;
    349 	} else
    350 		isreg = 0;
    351 
    352 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    353 		if (fwrite(buf, 1, nr, ofp) != nr) {
    354 			cwarn("%s", out);
    355 			goto err;
    356 		}
    357 
    358 	if (ferror(ifp) || fclose(ifp)) {
    359 		cwarn("%s", in);
    360 		goto err;
    361 	}
    362 	ifp = NULL;
    363 
    364 	if (fclose(ofp)) {
    365 		cwarn("%s", out);
    366 		goto err;
    367 	}
    368 
    369 	if (isreg && oreg) {
    370 		setfile(out, &sb);
    371 
    372 		if (unlink(in))
    373 			cwarn("%s", in);
    374 	}
    375 	return;
    376 
    377 err:	if (ofp) {
    378 		if (oreg)
    379 			(void)unlink(out);
    380 		(void)fclose(ofp);
    381 	}
    382 	if (ifp)
    383 		(void)fclose(ifp);
    384 }
    385 
    386 void
    387 setfile(name, fs)
    388 	char *name;
    389 	struct stat *fs;
    390 {
    391 	static struct timeval tv[2];
    392 
    393 	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
    394 
    395 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
    396 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
    397 	if (utimes(name, tv))
    398 		cwarn("utimes: %s", name);
    399 
    400 	/*
    401 	 * Changing the ownership probably won't succeed, unless we're root
    402 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
    403 	 * the mode; current BSD behavior is to remove all setuid bits on
    404 	 * chown.  If chown fails, lose setuid/setgid bits.
    405 	 */
    406 	if (chown(name, fs->st_uid, fs->st_gid)) {
    407 		if (errno != EPERM)
    408 			cwarn("chown: %s", name);
    409 		fs->st_mode &= ~(S_ISUID|S_ISGID);
    410 	}
    411 	if (chmod(name, fs->st_mode))
    412 		cwarn("chown: %s", name);
    413 
    414 	/*
    415 	 * Restore the file's flags.  However, do this only if the original
    416 	 * file had any flags set; this avoids a warning on file-systems that
    417 	 * do not support flags.
    418 	 */
    419 	if (fs->st_flags != 0 && chflags(name, fs->st_flags))
    420 		cwarn("chflags: %s", name);
    421 }
    422 
    423 int
    424 permission(fname)
    425 	char *fname;
    426 {
    427 	int ch, first;
    428 
    429 	if (!isatty(fileno(stderr)))
    430 		return (0);
    431 	(void)fprintf(stderr, "overwrite %s? ", fname);
    432 	first = ch = getchar();
    433 	while (ch != '\n' && ch != EOF)
    434 		ch = getchar();
    435 	return (first == 'y');
    436 }
    437 
    438 void
    439 usage(iscompress)
    440 	int iscompress;
    441 {
    442 	if (iscompress)
    443 		(void)fprintf(stderr,
    444 		    "usage: compress [-cfv] [-b bits] [file ...]\n");
    445 	else
    446 		(void)fprintf(stderr,
    447 		    "usage: uncompress [-c] [-b bits] [file ...]\n");
    448 	exit(1);
    449 }
    450 
    451 void
    452 #if __STDC__
    453 cwarnx(const char *fmt, ...)
    454 #else
    455 cwarnx(fmt, va_alist)
    456 	int eval;
    457 	const char *fmt;
    458 	va_dcl
    459 #endif
    460 {
    461 	va_list ap;
    462 #if __STDC__
    463 	va_start(ap, fmt);
    464 #else
    465 	va_start(ap);
    466 #endif
    467 	vwarnx(fmt, ap);
    468 	va_end(ap);
    469 	eval = 1;
    470 }
    471 
    472 void
    473 #if __STDC__
    474 cwarn(const char *fmt, ...)
    475 #else
    476 cwarn(fmt, va_alist)
    477 	int eval;
    478 	const char *fmt;
    479 	va_dcl
    480 #endif
    481 {
    482 	va_list ap;
    483 #if __STDC__
    484 	va_start(ap, fmt);
    485 #else
    486 	va_start(ap);
    487 #endif
    488 	vwarn(fmt, ap);
    489 	va_end(ap);
    490 	eval = 1;
    491 }
    492