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compress.c revision 1.8 
      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. All advertising materials mentioning features or use of this software
     14  *    must display the following acknowledgement:
     15  *	This product includes software developed by the University of
     16  *	California, Berkeley and its contributors.
     17  * 4. Neither the name of the University nor the names of its contributors
     18  *    may be used to endorse or promote products derived from this software
     19  *    without specific prior written permission.
     20  *
     21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     31  * SUCH DAMAGE.
     32  */
     33 
     34 #ifndef lint
     35 static char copyright[] =
     36 "@(#) Copyright (c) 1992, 1993\n\
     37 	The Regents of the University of California.  All rights reserved.\n";
     38 #endif /* not lint */
     39 
     40 #ifndef lint
     41 /*static char sccsid[] = "from: @(#)compress.c	8.2 (Berkeley) 1/7/94";*/
     42 static char *rcsid = "$Id: compress.c,v 1.8 1994/12/24 16:27:18 cgd Exp $";
     43 #endif /* not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/time.h>
     47 #include <sys/stat.h>
     48 
     49 #include <err.h>
     50 #include <errno.h>
     51 #include <stdio.h>
     52 #include <stdlib.h>
     53 #include <string.h>
     54 #include <unistd.h>
     55 
     56 #ifdef __STDC__
     57 #include <stdarg.h>
     58 #else
     59 #include <varargs.h>
     60 #endif
     61 
     62 void	compress __P((char *, char *, int));
     63 void	cwarn __P((const char *, ...));
     64 void	cwarnx __P((const char *, ...));
     65 void	decompress __P((char *, char *, int));
     66 int	permission __P((char *));
     67 void	setfile __P((char *, struct stat *));
     68 void	usage __P((int));
     69 
     70 extern FILE *zopen __P((const char *fname, const char *mode, int bits));
     71 
     72 int eval, force, verbose;
     73 
     74 int
     75 main(argc, argv)
     76 	int argc;
     77 	char *argv[];
     78 {
     79 	enum {COMPRESS, DECOMPRESS} style;
     80 	size_t len;
     81 	int bits, cat, ch;
     82 	char *p, newname[MAXPATHLEN];
     83 
     84 	if ((p = rindex(argv[0], '/')) == NULL)
     85 		p = argv[0];
     86 	else
     87 		++p;
     88 	if (!strcmp(p, "uncompress"))
     89 		style = DECOMPRESS;
     90 	else if (!strcmp(p, "compress"))
     91 		style = COMPRESS;
     92 	else
     93 		errx(1, "unknown program name");
     94 
     95 	bits = cat = 0;
     96 	while ((ch = getopt(argc, argv, "b:cdfv")) != EOF)
     97 		switch(ch) {
     98 		case 'b':
     99 			bits = strtol(optarg, &p, 10);
    100 			if (*p)
    101 				errx(1, "illegal bit count -- %s", optarg);
    102 			break;
    103 		case 'c':
    104 			cat = 1;
    105 			break;
    106 		case 'd':		/* Backward compatible. */
    107 			style = DECOMPRESS;
    108 			break;
    109 		case 'f':
    110 			force = 1;
    111 			break;
    112 		case 'v':
    113 			verbose = 1;
    114 			break;
    115 		case '?':
    116 		default:
    117 			usage(style == COMPRESS);
    118 		}
    119 	argc -= optind;
    120 	argv += optind;
    121 
    122 	if (argc == 0) {
    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 (cat) {
    141 				compress(*argv, "/dev/stdout", bits);
    142 				break;
    143 			}
    144 			if ((p = rindex(*argv, '.')) != NULL &&
    145 			    !strcmp(p, ".Z")) {
    146 				cwarnx("%s: name already has trailing .Z",
    147 				    *argv);
    148 				break;
    149 			}
    150 			len = strlen(*argv);
    151 			if (len > sizeof(newname) - 3) {
    152 				cwarnx("%s: name too long", *argv);
    153 				break;
    154 			}
    155 			memmove(newname, *argv, len);
    156 			newname[len] = '.';
    157 			newname[len + 1] = 'Z';
    158 			newname[len + 2] = '\0';
    159 			compress(*argv, newname, bits);
    160 			break;
    161 		case DECOMPRESS:
    162 			len = strlen(*argv);
    163 			if ((p = rindex(*argv, '.')) == NULL ||
    164 			    strcmp(p, ".Z")) {
    165 				if (len > sizeof(newname) - 3) {
    166 					cwarnx("%s: name too long", *argv);
    167 					break;
    168 				}
    169 				memmove(newname, *argv, len);
    170 				newname[len] = '.';
    171 				newname[len + 1] = 'Z';
    172 				newname[len + 2] = '\0';
    173 				decompress(newname,
    174 				    cat ? "/dev/stdout" : *argv, bits);
    175 			} else {
    176 				if (len - 2 > sizeof(newname) - 1) {
    177 					cwarnx("%s: name too long", *argv);
    178 					break;
    179 				}
    180 				memmove(newname, *argv, len - 2);
    181 				newname[len - 2] = '\0';
    182 				decompress(*argv,
    183 				    cat ? "/dev/stdout" : newname, bits);
    184 			}
    185 			break;
    186 		}
    187 	exit (eval);
    188 }
    189 
    190 void
    191 compress(in, out, bits)
    192 	char *in, *out;
    193 	int bits;
    194 {
    195 	register int nr;
    196 	struct stat isb, sb;
    197 	FILE *ifp, *ofp;
    198 	int exists, isreg, oreg;
    199 	u_char buf[1024];
    200 
    201 	exists = !stat(out, &sb);
    202 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    203 		return;
    204 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    205 
    206 	ifp = ofp = NULL;
    207 	if ((ifp = fopen(in, "r")) == NULL) {
    208 		cwarn("%s", in);
    209 		return;
    210 	}
    211 	if (stat(in, &isb)) {		/* DON'T FSTAT! */
    212 		cwarn("%s", in);
    213 		goto err;
    214 	}
    215 	if (!S_ISREG(isb.st_mode))
    216 		isreg = 0;
    217 
    218 	if ((ofp = zopen(out, "w", bits)) == NULL) {
    219 		cwarn("%s", out);
    220 		goto err;
    221 	}
    222 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    223 		if (fwrite(buf, 1, nr, ofp) != nr) {
    224 			cwarn("%s", out);
    225 			goto err;
    226 		}
    227 
    228 	if (ferror(ifp) || fclose(ifp)) {
    229 		cwarn("%s", in);
    230 		goto err;
    231 	}
    232 	ifp = NULL;
    233 
    234 	if (fclose(ofp)) {
    235 		cwarn("%s", out);
    236 		goto err;
    237 	}
    238 	ofp = NULL;
    239 
    240 	if (isreg) {
    241 		if (stat(out, &sb)) {
    242 			cwarn("%s", out);
    243 			goto err;
    244 		}
    245 
    246 		if (!force && sb.st_size >= isb.st_size) {
    247 			if (verbose)
    248 		(void)printf("%s: file would grow; left unmodified\n", in);
    249 			if (unlink(out))
    250 				cwarn("%s", out);
    251 			goto err;
    252 		}
    253 
    254 		setfile(out, &isb);
    255 
    256 		if (unlink(in))
    257 			cwarn("%s", in);
    258 
    259 		if (verbose) {
    260 			(void)printf("%s: ", out);
    261 			if (isb.st_size > sb.st_size)
    262 				(void)printf("%.0f%% compression\n",
    263 				    ((float)sb.st_size / isb.st_size) * 100.0);
    264 			else
    265 				(void)printf("%.0f%% expansion\n",
    266 				    ((float)isb.st_size / sb.st_size) * 100.0);
    267 		}
    268 	}
    269 	return;
    270 
    271 err:	if (ofp) {
    272 		if (oreg)
    273 			(void)unlink(out);
    274 		(void)fclose(ofp);
    275 	}
    276 	if (ifp)
    277 		(void)fclose(ifp);
    278 }
    279 
    280 void
    281 decompress(in, out, bits)
    282 	char *in, *out;
    283 	int bits;
    284 {
    285 	register int nr;
    286 	struct stat sb;
    287 	FILE *ifp, *ofp;
    288 	int exists, isreg, oreg;
    289 	u_char buf[1024];
    290 
    291 	exists = !stat(out, &sb);
    292 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    293 		return;
    294 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    295 
    296 	ifp = ofp = NULL;
    297 	if ((ofp = fopen(out, "w")) == NULL) {
    298 		cwarn("%s", out);
    299 		return;
    300 	}
    301 
    302 	if ((ifp = zopen(in, "r", bits)) == NULL) {
    303 		cwarn("%s", in);
    304 		goto err;
    305 	}
    306 	if (stat(in, &sb)) {
    307 		cwarn("%s", in);
    308 		goto err;
    309 	}
    310 	if (!S_ISREG(sb.st_mode))
    311 		isreg = 0;
    312 
    313 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    314 		if (fwrite(buf, 1, nr, ofp) != nr) {
    315 			cwarn("%s", out);
    316 			goto err;
    317 		}
    318 
    319 	if (ferror(ifp) || fclose(ifp)) {
    320 		cwarn("%s", in);
    321 		goto err;
    322 	}
    323 	ifp = NULL;
    324 
    325 	if (fclose(ofp)) {
    326 		cwarn("%s", out);
    327 		goto err;
    328 	}
    329 
    330 	if (isreg) {
    331 		setfile(out, &sb);
    332 
    333 		if (unlink(in))
    334 			cwarn("%s", in);
    335 	}
    336 	return;
    337 
    338 err:	if (ofp) {
    339 		if (oreg)
    340 			(void)unlink(out);
    341 		(void)fclose(ofp);
    342 	}
    343 	if (ifp)
    344 		(void)fclose(ifp);
    345 }
    346 
    347 void
    348 setfile(name, fs)
    349 	char *name;
    350 	register struct stat *fs;
    351 {
    352 	static struct timeval tv[2];
    353 
    354 	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
    355 
    356 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
    357 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
    358 	if (utimes(name, tv))
    359 		cwarn("utimes: %s", name);
    360 
    361 	/*
    362 	 * Changing the ownership probably won't succeed, unless we're root
    363 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
    364 	 * the mode; current BSD behavior is to remove all setuid bits on
    365 	 * chown.  If chown fails, lose setuid/setgid bits.
    366 	 */
    367 	if (chown(name, fs->st_uid, fs->st_gid)) {
    368 		if (errno != EPERM)
    369 			cwarn("chown: %s", name);
    370 		fs->st_mode &= ~(S_ISUID|S_ISGID);
    371 	}
    372 	if (chmod(name, fs->st_mode))
    373 		cwarn("chown: %s", name);
    374 
    375 	if (chflags(name, fs->st_flags))
    376 		cwarn("chflags: %s", name);
    377 }
    378 
    379 int
    380 permission(fname)
    381 	char *fname;
    382 {
    383 	int ch, first;
    384 
    385 	if (!isatty(fileno(stderr)))
    386 		return (0);
    387 	(void)fprintf(stderr, "overwrite %s? ", fname);
    388 	first = ch = getchar();
    389 	while (ch != '\n' && ch != EOF)
    390 		ch = getchar();
    391 	return (first == 'y');
    392 }
    393 
    394 void
    395 usage(iscompress)
    396 	int iscompress;
    397 {
    398 	if (iscompress)
    399 		(void)fprintf(stderr,
    400 		    "usage: compress [-cfv] [-b bits] [file ...]\n");
    401 	else
    402 		(void)fprintf(stderr,
    403 		    "usage: uncompress [-c] [-b bits] [file ...]\n");
    404 	exit(1);
    405 }
    406 
    407 void
    408 #if __STDC__
    409 cwarnx(const char *fmt, ...)
    410 #else
    411 cwarnx(fmt, va_alist)
    412 	int eval;
    413 	const char *fmt;
    414 	va_dcl
    415 #endif
    416 {
    417 	va_list ap;
    418 #if __STDC__
    419 	va_start(ap, fmt);
    420 #else
    421 	va_start(ap);
    422 #endif
    423 	vwarnx(fmt, ap);
    424 	va_end(ap);
    425 	eval = 1;
    426 }
    427 
    428 void
    429 #if __STDC__
    430 cwarn(const char *fmt, ...)
    431 #else
    432 cwarn(fmt, va_alist)
    433 	int eval;
    434 	const char *fmt;
    435 	va_dcl
    436 #endif
    437 {
    438 	va_list ap;
    439 #if __STDC__
    440 	va_start(ap, fmt);
    441 #else
    442 	va_start(ap);
    443 #endif
    444 	vwarn(fmt, ap);
    445 	va_end(ap);
    446 	eval = 1;
    447 }
    448