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compress.c revision 1.1.1.2 
      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[] = "@(#)compress.c	8.2 (Berkeley) 1/7/94";
     42 #endif /* not lint */
     43 
     44 #include <sys/param.h>
     45 #include <sys/time.h>
     46 #include <sys/stat.h>
     47 
     48 #include <err.h>
     49 #include <errno.h>
     50 #include <stdio.h>
     51 #include <stdlib.h>
     52 #include <string.h>
     53 #include <unistd.h>
     54 
     55 #ifdef __STDC__
     56 #include <stdarg.h>
     57 #else
     58 #include <varargs.h>
     59 #endif
     60 
     61 void	compress __P((char *, char *, int));
     62 void	cwarn __P((const char *, ...));
     63 void	cwarnx __P((const char *, ...));
     64 void	decompress __P((char *, char *, int));
     65 int	permission __P((char *));
     66 void	setfile __P((char *, struct stat *));
     67 void	usage __P((int));
     68 
     69 int eval, force, verbose;
     70 
     71 int
     72 main(argc, argv)
     73 	int argc;
     74 	char *argv[];
     75 {
     76 	enum {COMPRESS, DECOMPRESS} style;
     77 	size_t len;
     78 	int bits, cat, ch;
     79 	char *p, newname[MAXPATHLEN];
     80 
     81 	if ((p = rindex(argv[0], '/')) == NULL)
     82 		p = argv[0];
     83 	else
     84 		++p;
     85 	if (!strcmp(p, "uncompress"))
     86 		style = DECOMPRESS;
     87 	else if (!strcmp(p, "compress"))
     88 		style = COMPRESS;
     89 	else
     90 		errx(1, "unknown program name");
     91 
     92 	bits = cat = 0;
     93 	while ((ch = getopt(argc, argv, "b:cdfv")) != EOF)
     94 		switch(ch) {
     95 		case 'b':
     96 			bits = strtol(optarg, &p, 10);
     97 			if (*p)
     98 				errx(1, "illegal bit count -- %s", optarg);
     99 			break;
    100 		case 'c':
    101 			cat = 1;
    102 			break;
    103 		case 'd':		/* Backward compatible. */
    104 			style = DECOMPRESS;
    105 			break;
    106 		case 'f':
    107 			force = 1;
    108 			break;
    109 		case 'v':
    110 			verbose = 1;
    111 			break;
    112 		case '?':
    113 		default:
    114 			usage(style == COMPRESS);
    115 		}
    116 	argc -= optind;
    117 	argv += optind;
    118 
    119 	if (argc == 0) {
    120 		switch(style) {
    121 		case COMPRESS:
    122 			(void)compress("/dev/stdin", "/dev/stdout", bits);
    123 			break;
    124 		case DECOMPRESS:
    125 			(void)decompress("/dev/stdin", "/dev/stdout", bits);
    126 			break;
    127 		}
    128 		exit (eval);
    129 	}
    130 
    131 	if (cat == 1 && argc > 1)
    132 		errx(1, "the -c option permits only a single file argument");
    133 
    134 	for (; *argv; ++argv)
    135 		switch(style) {
    136 		case COMPRESS:
    137 			if (cat) {
    138 				compress(*argv, "/dev/stdout", bits);
    139 				break;
    140 			}
    141 			if ((p = rindex(*argv, '.')) != NULL &&
    142 			    !strcmp(p, ".Z")) {
    143 				cwarnx("%s: name already has trailing .Z",
    144 				    *argv);
    145 				break;
    146 			}
    147 			len = strlen(*argv);
    148 			if (len > sizeof(newname) - 3) {
    149 				cwarnx("%s: name too long", *argv);
    150 				break;
    151 			}
    152 			memmove(newname, *argv, len);
    153 			newname[len] = '.';
    154 			newname[len + 1] = 'Z';
    155 			newname[len + 2] = '\0';
    156 			compress(*argv, newname, bits);
    157 			break;
    158 		case DECOMPRESS:
    159 			len = strlen(*argv);
    160 			if ((p = rindex(*argv, '.')) == NULL ||
    161 			    strcmp(p, ".Z")) {
    162 				if (len > sizeof(newname) - 3) {
    163 					cwarnx("%s: name too long", *argv);
    164 					break;
    165 				}
    166 				memmove(newname, *argv, len);
    167 				newname[len] = '.';
    168 				newname[len + 1] = 'Z';
    169 				newname[len + 2] = '\0';
    170 				decompress(newname,
    171 				    cat ? "/dev/stdout" : *argv, bits);
    172 			} else {
    173 				if (len - 2 > sizeof(newname) - 1) {
    174 					cwarnx("%s: name too long", *argv);
    175 					break;
    176 				}
    177 				memmove(newname, *argv, len - 2);
    178 				newname[len - 2] = '\0';
    179 				decompress(*argv,
    180 				    cat ? "/dev/stdout" : newname, bits);
    181 			}
    182 			break;
    183 		}
    184 	exit (eval);
    185 }
    186 
    187 void
    188 compress(in, out, bits)
    189 	char *in, *out;
    190 	int bits;
    191 {
    192 	register int nr;
    193 	struct stat isb, sb;
    194 	FILE *ifp, *ofp;
    195 	int exists, isreg, oreg;
    196 	u_char buf[1024];
    197 
    198 	exists = !stat(out, &sb);
    199 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    200 		return;
    201 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    202 
    203 	ifp = ofp = NULL;
    204 	if ((ifp = fopen(in, "r")) == NULL) {
    205 		cwarn("%s", in);
    206 		return;
    207 	}
    208 	if (stat(in, &isb)) {		/* DON'T FSTAT! */
    209 		cwarn("%s", in);
    210 		goto err;
    211 	}
    212 	if (!S_ISREG(isb.st_mode))
    213 		isreg = 0;
    214 
    215 	if ((ofp = zopen(out, "w", bits)) == NULL) {
    216 		cwarn("%s", out);
    217 		goto err;
    218 	}
    219 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    220 		if (fwrite(buf, 1, nr, ofp) != nr) {
    221 			cwarn("%s", out);
    222 			goto err;
    223 		}
    224 
    225 	if (ferror(ifp) || fclose(ifp)) {
    226 		cwarn("%s", in);
    227 		goto err;
    228 	}
    229 	ifp = NULL;
    230 
    231 	if (fclose(ofp)) {
    232 		cwarn("%s", out);
    233 		goto err;
    234 	}
    235 	ofp = NULL;
    236 
    237 	if (isreg) {
    238 		if (stat(out, &sb)) {
    239 			cwarn("%s", out);
    240 			goto err;
    241 		}
    242 
    243 		if (!force && sb.st_size >= isb.st_size) {
    244 			if (verbose)
    245 		(void)printf("%s: file would grow; left unmodified\n", in);
    246 			if (unlink(out))
    247 				cwarn("%s", out);
    248 			goto err;
    249 		}
    250 
    251 		setfile(out, &isb);
    252 
    253 		if (unlink(in))
    254 			cwarn("%s", in);
    255 
    256 		if (verbose) {
    257 			(void)printf("%s: ", out);
    258 			if (isb.st_size > sb.st_size)
    259 				(void)printf("%.0f%% compression\n",
    260 				    ((float)sb.st_size / isb.st_size) * 100.0);
    261 			else
    262 				(void)printf("%.0f%% expansion\n",
    263 				    ((float)isb.st_size / sb.st_size) * 100.0);
    264 		}
    265 	}
    266 	return;
    267 
    268 err:	if (ofp) {
    269 		if (oreg)
    270 			(void)unlink(out);
    271 		(void)fclose(ofp);
    272 	}
    273 	if (ifp)
    274 		(void)fclose(ifp);
    275 }
    276 
    277 void
    278 decompress(in, out, bits)
    279 	char *in, *out;
    280 	int bits;
    281 {
    282 	register int nr;
    283 	struct stat sb;
    284 	FILE *ifp, *ofp;
    285 	int exists, isreg, oreg;
    286 	u_char buf[1024];
    287 
    288 	exists = !stat(out, &sb);
    289 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    290 		return;
    291 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    292 
    293 	ifp = ofp = NULL;
    294 	if ((ofp = fopen(out, "w")) == NULL) {
    295 		cwarn("%s", out);
    296 		return;
    297 	}
    298 
    299 	if ((ifp = zopen(in, "r", bits)) == NULL) {
    300 		cwarn("%s", in);
    301 		goto err;
    302 	}
    303 	if (stat(in, &sb)) {
    304 		cwarn("%s", in);
    305 		goto err;
    306 	}
    307 	if (!S_ISREG(sb.st_mode))
    308 		isreg = 0;
    309 
    310 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    311 		if (fwrite(buf, 1, nr, ofp) != nr) {
    312 			cwarn("%s", out);
    313 			goto err;
    314 		}
    315 
    316 	if (ferror(ifp) || fclose(ifp)) {
    317 		cwarn("%s", in);
    318 		goto err;
    319 	}
    320 	ifp = NULL;
    321 
    322 	if (fclose(ofp)) {
    323 		cwarn("%s", out);
    324 		goto err;
    325 	}
    326 
    327 	if (isreg) {
    328 		setfile(out, &sb);
    329 
    330 		if (unlink(in))
    331 			cwarn("%s", in);
    332 	}
    333 	return;
    334 
    335 err:	if (ofp) {
    336 		if (oreg)
    337 			(void)unlink(out);
    338 		(void)fclose(ofp);
    339 	}
    340 	if (ifp)
    341 		(void)fclose(ifp);
    342 }
    343 
    344 void
    345 setfile(name, fs)
    346 	char *name;
    347 	register struct stat *fs;
    348 {
    349 	static struct timeval tv[2];
    350 
    351 	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
    352 
    353 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
    354 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
    355 	if (utimes(name, tv))
    356 		cwarn("utimes: %s", name);
    357 
    358 	/*
    359 	 * Changing the ownership probably won't succeed, unless we're root
    360 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
    361 	 * the mode; current BSD behavior is to remove all setuid bits on
    362 	 * chown.  If chown fails, lose setuid/setgid bits.
    363 	 */
    364 	if (chown(name, fs->st_uid, fs->st_gid)) {
    365 		if (errno != EPERM)
    366 			cwarn("chown: %s", name);
    367 		fs->st_mode &= ~(S_ISUID|S_ISGID);
    368 	}
    369 	if (chmod(name, fs->st_mode))
    370 		cwarn("chown: %s", name);
    371 
    372 	if (chflags(name, fs->st_flags))
    373 		cwarn("chflags: %s", name);
    374 }
    375 
    376 int
    377 permission(fname)
    378 	char *fname;
    379 {
    380 	int ch, first;
    381 
    382 	if (!isatty(fileno(stderr)))
    383 		return (0);
    384 	(void)fprintf(stderr, "overwrite %s? ", fname);
    385 	first = ch = getchar();
    386 	while (ch != '\n' && ch != EOF)
    387 		ch = getchar();
    388 	return (first == 'y');
    389 }
    390 
    391 void
    392 usage(iscompress)
    393 	int iscompress;
    394 {
    395 	if (iscompress)
    396 		(void)fprintf(stderr,
    397 		    "usage: compress [-cfv] [-b bits] [file ...]\n");
    398 	else
    399 		(void)fprintf(stderr,
    400 		    "usage: uncompress [-c] [-b bits] [file ...]\n");
    401 	exit(1);
    402 }
    403 
    404 void
    405 #if __STDC__
    406 cwarnx(const char *fmt, ...)
    407 #else
    408 cwarnx(fmt, va_alist)
    409 	int eval;
    410 	const char *fmt;
    411 	va_dcl
    412 #endif
    413 {
    414 	va_list ap;
    415 #if __STDC__
    416 	va_start(ap, fmt);
    417 #else
    418 	va_start(ap);
    419 #endif
    420 	vwarnx(fmt, ap);
    421 	va_end(ap);
    422 	eval = 1;
    423 }
    424 
    425 void
    426 #if __STDC__
    427 cwarn(const char *fmt, ...)
    428 #else
    429 cwarn(fmt, va_alist)
    430 	int eval;
    431 	const char *fmt;
    432 	va_dcl
    433 #endif
    434 {
    435 	va_list ap;
    436 #if __STDC__
    437 	va_start(ap, fmt);
    438 #else
    439 	va_start(ap);
    440 #endif
    441 	vwarn(fmt, ap);
    442 	va_end(ap);
    443 	eval = 1;
    444 }
    445