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compress.c revision 1.15 
      1 /*	$NetBSD: compress.c,v 1.15 1997/10/19 15:18:43 mycroft 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 1.15 1997/10/19 15:18:43 mycroft 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;
     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
    100 		errx(1, "unknown program name");
    101 
    102 	bits = cat = 0;
    103 	while ((ch = getopt(argc, argv, "b:cdfv")) != -1)
    104 		switch(ch) {
    105 		case 'b':
    106 			bits = strtol(optarg, &p, 10);
    107 			if (*p)
    108 				errx(1, "illegal bit count -- %s", optarg);
    109 			break;
    110 		case 'c':
    111 			cat = 1;
    112 			break;
    113 		case 'd':		/* Backward compatible. */
    114 			style = DECOMPRESS;
    115 			break;
    116 		case 'f':
    117 			force = 1;
    118 			break;
    119 		case 'v':
    120 			verbose = 1;
    121 			break;
    122 		case '?':
    123 		default:
    124 			usage(style == COMPRESS);
    125 		}
    126 	argc -= optind;
    127 	argv += optind;
    128 
    129 	if (argc == 0) {
    130 		switch(style) {
    131 		case COMPRESS:
    132 			isstdout = 1;
    133 			isstdin = 1;
    134 			(void)compress("/dev/stdin", "/dev/stdout", bits);
    135 			break;
    136 		case DECOMPRESS:
    137 			isstdout = 1;
    138 			isstdin = 1;
    139 			(void)decompress("/dev/stdin", "/dev/stdout", bits);
    140 			break;
    141 		}
    142 		exit (eval);
    143 	}
    144 
    145 	if (cat == 1 && argc > 1)
    146 		errx(1, "the -c option permits only a single file argument");
    147 
    148 	for (; *argv; ++argv) {
    149 		isstdout = 0;
    150 		switch(style) {
    151 		case COMPRESS:
    152 			if (cat) {
    153 				isstdout = 1;
    154 				compress(*argv, "/dev/stdout", bits);
    155 				break;
    156 			}
    157 			if ((p = strrchr(*argv, '.')) != NULL &&
    158 			    !strcmp(p, ".Z")) {
    159 				cwarnx("%s: name already has trailing .Z",
    160 				    *argv);
    161 				break;
    162 			}
    163 			len = strlen(*argv);
    164 			if (len > sizeof(newname) - 3) {
    165 				cwarnx("%s: name too long", *argv);
    166 				break;
    167 			}
    168 			memmove(newname, *argv, len);
    169 			newname[len] = '.';
    170 			newname[len + 1] = 'Z';
    171 			newname[len + 2] = '\0';
    172 			compress(*argv, newname, bits);
    173 			break;
    174 		case DECOMPRESS:
    175 			len = strlen(*argv);
    176 			if ((p = strrchr(*argv, '.')) == NULL ||
    177 			    strcmp(p, ".Z")) {
    178 				if (len > sizeof(newname) - 3) {
    179 					cwarnx("%s: name too long", *argv);
    180 					break;
    181 				}
    182 				memmove(newname, *argv, len);
    183 				newname[len] = '.';
    184 				newname[len + 1] = 'Z';
    185 				newname[len + 2] = '\0';
    186 				decompress(newname,
    187 				    cat ? "/dev/stdout" : *argv, bits);
    188 				if (cat)
    189 					isstdout = 1;
    190 			} else {
    191 				if (len - 2 > sizeof(newname) - 1) {
    192 					cwarnx("%s: name too long", *argv);
    193 					break;
    194 				}
    195 				memmove(newname, *argv, len - 2);
    196 				newname[len - 2] = '\0';
    197 				decompress(*argv,
    198 				    cat ? "/dev/stdout" : newname, bits);
    199 				if (cat)
    200 					isstdout = 1;
    201 			}
    202 			break;
    203 		}
    204 	}
    205 	exit (eval);
    206 }
    207 
    208 void
    209 compress(in, out, bits)
    210 	char *in, *out;
    211 	int bits;
    212 {
    213 	int nr;
    214 	struct stat isb, sb;
    215 	FILE *ifp, *ofp;
    216 	int exists, isreg, oreg;
    217 	u_char buf[BUFSIZ];
    218 
    219 	if (!isstdout) {
    220 		exists = !stat(out, &sb);
    221 		if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    222 			return;
    223 		oreg = !exists || S_ISREG(sb.st_mode);
    224 	} else
    225 		oreg = 0;
    226 
    227 	ifp = ofp = NULL;
    228 	if ((ifp = fopen(in, "r")) == NULL) {
    229 		cwarn("%s", in);
    230 		return;
    231 	}
    232 
    233 	if (!isstdin) {
    234 		if (stat(in, &isb)) {		/* DON'T FSTAT! */
    235 			cwarn("%s", in);
    236 			goto err;
    237 		}
    238 		if (!S_ISREG(isb.st_mode))
    239 			isreg = 0;
    240 		else
    241 			isreg = 1;
    242 	} else
    243 		isreg = 0;
    244 
    245 	if ((ofp = zopen(out, "w", bits)) == NULL) {
    246 		cwarn("%s", out);
    247 		goto err;
    248 	}
    249 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    250 		if (fwrite(buf, 1, nr, ofp) != nr) {
    251 			cwarn("%s", out);
    252 			goto err;
    253 		}
    254 
    255 	if (ferror(ifp) || fclose(ifp)) {
    256 		cwarn("%s", in);
    257 		goto err;
    258 	}
    259 	ifp = NULL;
    260 
    261 	if (fclose(ofp)) {
    262 		cwarn("%s", out);
    263 		goto err;
    264 	}
    265 	ofp = NULL;
    266 
    267 	if (isreg && oreg) {
    268 		if (stat(out, &sb)) {
    269 			cwarn("%s", out);
    270 			goto err;
    271 		}
    272 
    273 		if (!force && sb.st_size >= isb.st_size) {
    274 			if (verbose)
    275 		(void)printf("%s: file would grow; left unmodified\n", in);
    276 			if (unlink(out))
    277 				cwarn("%s", out);
    278 			goto err;
    279 		}
    280 
    281 		setfile(out, &isb);
    282 
    283 		if (unlink(in))
    284 			cwarn("%s", in);
    285 
    286 		if (verbose) {
    287 			(void)printf("%s: ", out);
    288 			if (isb.st_size > sb.st_size)
    289 				(void)printf("%.0f%% compression\n",
    290 				    ((double)sb.st_size / isb.st_size) * 100.0);
    291 			else
    292 				(void)printf("%.0f%% expansion\n",
    293 				    ((double)isb.st_size / sb.st_size) * 100.0);
    294 		}
    295 	}
    296 	return;
    297 
    298 err:	if (ofp) {
    299 		if (oreg)
    300 			(void)unlink(out);
    301 		(void)fclose(ofp);
    302 	}
    303 	if (ifp)
    304 		(void)fclose(ifp);
    305 }
    306 
    307 void
    308 decompress(in, out, bits)
    309 	char *in, *out;
    310 	int bits;
    311 {
    312 	int nr;
    313 	struct stat sb;
    314 	FILE *ifp, *ofp;
    315 	int exists, isreg, oreg;
    316 	u_char buf[BUFSIZ];
    317 
    318 	if (!isstdout) {
    319 		exists = !stat(out, &sb);
    320 		if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    321 			return;
    322 		oreg = !exists || S_ISREG(sb.st_mode);
    323 	} else
    324 		oreg = 0;
    325 
    326 	ifp = ofp = NULL;
    327 	if ((ofp = fopen(out, "w")) == NULL) {
    328 		cwarn("%s", out);
    329 		return;
    330 	}
    331 
    332 	if ((ifp = zopen(in, "r", bits)) == NULL) {
    333 		cwarn("%s", in);
    334 		goto err;
    335 	}
    336 	if (!isstdin) {
    337 		if (stat(in, &sb)) {
    338 			cwarn("%s", in);
    339 			goto err;
    340 		}
    341 		if (!S_ISREG(sb.st_mode))
    342 			isreg = 0;
    343 		else
    344 			isreg = 1;
    345 	} else
    346 		isreg = 0;
    347 
    348 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    349 		if (fwrite(buf, 1, nr, ofp) != nr) {
    350 			cwarn("%s", out);
    351 			goto err;
    352 		}
    353 
    354 	if (ferror(ifp) || fclose(ifp)) {
    355 		cwarn("%s", in);
    356 		goto err;
    357 	}
    358 	ifp = NULL;
    359 
    360 	if (fclose(ofp)) {
    361 		cwarn("%s", out);
    362 		goto err;
    363 	}
    364 
    365 	if (isreg && oreg) {
    366 		setfile(out, &sb);
    367 
    368 		if (unlink(in))
    369 			cwarn("%s", in);
    370 	}
    371 	return;
    372 
    373 err:	if (ofp) {
    374 		if (oreg)
    375 			(void)unlink(out);
    376 		(void)fclose(ofp);
    377 	}
    378 	if (ifp)
    379 		(void)fclose(ifp);
    380 }
    381 
    382 void
    383 setfile(name, fs)
    384 	char *name;
    385 	struct stat *fs;
    386 {
    387 	static struct timeval tv[2];
    388 
    389 	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
    390 
    391 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
    392 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
    393 	if (utimes(name, tv))
    394 		cwarn("utimes: %s", name);
    395 
    396 	/*
    397 	 * Changing the ownership probably won't succeed, unless we're root
    398 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
    399 	 * the mode; current BSD behavior is to remove all setuid bits on
    400 	 * chown.  If chown fails, lose setuid/setgid bits.
    401 	 */
    402 	if (chown(name, fs->st_uid, fs->st_gid)) {
    403 		if (errno != EPERM)
    404 			cwarn("chown: %s", name);
    405 		fs->st_mode &= ~(S_ISUID|S_ISGID);
    406 	}
    407 	if (chmod(name, fs->st_mode))
    408 		cwarn("chown: %s", name);
    409 
    410 	if (chflags(name, fs->st_flags))
    411 		cwarn("chflags: %s", name);
    412 }
    413 
    414 int
    415 permission(fname)
    416 	char *fname;
    417 {
    418 	int ch, first;
    419 
    420 	if (!isatty(fileno(stderr)))
    421 		return (0);
    422 	(void)fprintf(stderr, "overwrite %s? ", fname);
    423 	first = ch = getchar();
    424 	while (ch != '\n' && ch != EOF)
    425 		ch = getchar();
    426 	return (first == 'y');
    427 }
    428 
    429 void
    430 usage(iscompress)
    431 	int iscompress;
    432 {
    433 	if (iscompress)
    434 		(void)fprintf(stderr,
    435 		    "usage: compress [-cfv] [-b bits] [file ...]\n");
    436 	else
    437 		(void)fprintf(stderr,
    438 		    "usage: uncompress [-c] [-b bits] [file ...]\n");
    439 	exit(1);
    440 }
    441 
    442 void
    443 #if __STDC__
    444 cwarnx(const char *fmt, ...)
    445 #else
    446 cwarnx(fmt, va_alist)
    447 	int eval;
    448 	const char *fmt;
    449 	va_dcl
    450 #endif
    451 {
    452 	va_list ap;
    453 #if __STDC__
    454 	va_start(ap, fmt);
    455 #else
    456 	va_start(ap);
    457 #endif
    458 	vwarnx(fmt, ap);
    459 	va_end(ap);
    460 	eval = 1;
    461 }
    462 
    463 void
    464 #if __STDC__
    465 cwarn(const char *fmt, ...)
    466 #else
    467 cwarn(fmt, va_alist)
    468 	int eval;
    469 	const char *fmt;
    470 	va_dcl
    471 #endif
    472 {
    473 	va_list ap;
    474 #if __STDC__
    475 	va_start(ap, fmt);
    476 #else
    477 	va_start(ap);
    478 #endif
    479 	vwarn(fmt, ap);
    480 	va_end(ap);
    481 	eval = 1;
    482 }
    483