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compress.c revision 1.9.6.1 
      1 /*	$NetBSD: compress.c,v 1.9.6.1 1997/01/26 03:20:10 rat 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 #ifndef lint
     37 static char copyright[] =
     38 "@(#) 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 static char rcsid[] = "$NetBSD: compress.c,v 1.9.6.1 1997/01/26 03:20:10 rat 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 extern FILE *zopen __P((const char *fname, const char *mode, int bits));
     76 
     77 int eval, force, verbose;
     78 
     79 int
     80 main(argc, argv)
     81 	int argc;
     82 	char *argv[];
     83 {
     84 	enum {COMPRESS, DECOMPRESS} style;
     85 	size_t len;
     86 	int bits, cat, ch;
     87 	char *p, newname[MAXPATHLEN];
     88 
     89 	if ((p = rindex(argv[0], '/')) == NULL)
     90 		p = argv[0];
     91 	else
     92 		++p;
     93 	if (!strcmp(p, "uncompress"))
     94 		style = DECOMPRESS;
     95 	else if (!strcmp(p, "compress"))
     96 		style = COMPRESS;
     97 	else
     98 		errx(1, "unknown program name");
     99 
    100 	bits = cat = 0;
    101 	while ((ch = getopt(argc, argv, "b:cdfv")) != EOF)
    102 		switch(ch) {
    103 		case 'b':
    104 			bits = strtol(optarg, &p, 10);
    105 			if (*p)
    106 				errx(1, "illegal bit count -- %s", optarg);
    107 			break;
    108 		case 'c':
    109 			cat = 1;
    110 			break;
    111 		case 'd':		/* Backward compatible. */
    112 			style = DECOMPRESS;
    113 			break;
    114 		case 'f':
    115 			force = 1;
    116 			break;
    117 		case 'v':
    118 			verbose = 1;
    119 			break;
    120 		case '?':
    121 		default:
    122 			usage(style == COMPRESS);
    123 		}
    124 	argc -= optind;
    125 	argv += optind;
    126 
    127 	if (argc == 0) {
    128 		switch(style) {
    129 		case COMPRESS:
    130 			(void)compress("/dev/stdin", "/dev/stdout", bits);
    131 			break;
    132 		case DECOMPRESS:
    133 			(void)decompress("/dev/stdin", "/dev/stdout", bits);
    134 			break;
    135 		}
    136 		exit (eval);
    137 	}
    138 
    139 	if (cat == 1 && argc > 1)
    140 		errx(1, "the -c option permits only a single file argument");
    141 
    142 	for (; *argv; ++argv) {
    143 		switch(style) {
    144 		case COMPRESS:
    145 			if (cat) {
    146 				compress(*argv, "/dev/stdout", bits);
    147 				break;
    148 			}
    149 			if ((p = rindex(*argv, '.')) != NULL &&
    150 			    !strcmp(p, ".Z")) {
    151 				cwarnx("%s: name already has trailing .Z",
    152 				    *argv);
    153 				break;
    154 			}
    155 			len = strlen(*argv);
    156 			if (len > sizeof(newname) - 3) {
    157 				cwarnx("%s: name too long", *argv);
    158 				break;
    159 			}
    160 			memmove(newname, *argv, len);
    161 			newname[len] = '.';
    162 			newname[len + 1] = 'Z';
    163 			newname[len + 2] = '\0';
    164 			compress(*argv, newname, bits);
    165 			break;
    166 		case DECOMPRESS:
    167 			len = strlen(*argv);
    168 			if ((p = rindex(*argv, '.')) == NULL ||
    169 			    strcmp(p, ".Z")) {
    170 				if (len > sizeof(newname) - 3) {
    171 					cwarnx("%s: name too long", *argv);
    172 					break;
    173 				}
    174 				memmove(newname, *argv, len);
    175 				newname[len] = '.';
    176 				newname[len + 1] = 'Z';
    177 				newname[len + 2] = '\0';
    178 				decompress(newname,
    179 				    cat ? "/dev/stdout" : *argv, bits);
    180 			} else {
    181 				if (len - 2 > sizeof(newname) - 1) {
    182 					cwarnx("%s: name too long", *argv);
    183 					break;
    184 				}
    185 				memmove(newname, *argv, len - 2);
    186 				newname[len - 2] = '\0';
    187 				decompress(*argv,
    188 				    cat ? "/dev/stdout" : newname, bits);
    189 			}
    190 			break;
    191 		}
    192 	}
    193 	exit (eval);
    194 }
    195 
    196 void
    197 compress(in, out, bits)
    198 	char *in, *out;
    199 	int bits;
    200 {
    201 	register int nr;
    202 	struct stat isb, sb;
    203 	FILE *ifp, *ofp;
    204 	int exists, isreg, oreg;
    205 	u_char buf[1024];
    206 
    207 	exists = !stat(out, &sb);
    208 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    209 		return;
    210 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    211 
    212 	ifp = ofp = NULL;
    213 	if ((ifp = fopen(in, "r")) == NULL) {
    214 		cwarn("%s", in);
    215 		return;
    216 	}
    217 	if (stat(in, &isb)) {		/* DON'T FSTAT! */
    218 		cwarn("%s", in);
    219 		goto err;
    220 	}
    221 	if (!S_ISREG(isb.st_mode))
    222 		isreg = 0;
    223 
    224 	if ((ofp = zopen(out, "w", bits)) == NULL) {
    225 		cwarn("%s", out);
    226 		goto err;
    227 	}
    228 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    229 		if (fwrite(buf, 1, nr, ofp) != nr) {
    230 			cwarn("%s", out);
    231 			goto err;
    232 		}
    233 
    234 	if (ferror(ifp) || fclose(ifp)) {
    235 		cwarn("%s", in);
    236 		goto err;
    237 	}
    238 	ifp = NULL;
    239 
    240 	if (fclose(ofp)) {
    241 		cwarn("%s", out);
    242 		goto err;
    243 	}
    244 	ofp = NULL;
    245 
    246 	if (isreg) {
    247 		if (stat(out, &sb)) {
    248 			cwarn("%s", out);
    249 			goto err;
    250 		}
    251 
    252 		if (!force && sb.st_size >= isb.st_size) {
    253 			if (verbose)
    254 		(void)printf("%s: file would grow; left unmodified\n", in);
    255 			if (unlink(out))
    256 				cwarn("%s", out);
    257 			goto err;
    258 		}
    259 
    260 		setfile(out, &isb);
    261 
    262 		if (unlink(in))
    263 			cwarn("%s", in);
    264 
    265 		if (verbose) {
    266 			(void)printf("%s: ", out);
    267 			if (isb.st_size > sb.st_size)
    268 				(void)printf("%.0f%% compression\n",
    269 				    ((float)sb.st_size / isb.st_size) * 100.0);
    270 			else
    271 				(void)printf("%.0f%% expansion\n",
    272 				    ((float)isb.st_size / sb.st_size) * 100.0);
    273 		}
    274 	}
    275 	return;
    276 
    277 err:	if (ofp) {
    278 		if (oreg)
    279 			(void)unlink(out);
    280 		(void)fclose(ofp);
    281 	}
    282 	if (ifp)
    283 		(void)fclose(ifp);
    284 }
    285 
    286 void
    287 decompress(in, out, bits)
    288 	char *in, *out;
    289 	int bits;
    290 {
    291 	register int nr;
    292 	struct stat sb;
    293 	FILE *ifp, *ofp;
    294 	int exists, isreg, oreg;
    295 	u_char buf[1024];
    296 
    297 	exists = !stat(out, &sb);
    298 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    299 		return;
    300 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    301 
    302 	ifp = ofp = NULL;
    303 	if ((ofp = fopen(out, "w")) == NULL) {
    304 		cwarn("%s", out);
    305 		return;
    306 	}
    307 
    308 	if ((ifp = zopen(in, "r", bits)) == NULL) {
    309 		cwarn("%s", in);
    310 		goto err;
    311 	}
    312 	if (stat(in, &sb)) {
    313 		cwarn("%s", in);
    314 		goto err;
    315 	}
    316 	if (!S_ISREG(sb.st_mode))
    317 		isreg = 0;
    318 
    319 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    320 		if (fwrite(buf, 1, nr, ofp) != nr) {
    321 			cwarn("%s", out);
    322 			goto err;
    323 		}
    324 
    325 	if (ferror(ifp) || fclose(ifp)) {
    326 		cwarn("%s", in);
    327 		goto err;
    328 	}
    329 	ifp = NULL;
    330 
    331 	if (fclose(ofp)) {
    332 		cwarn("%s", out);
    333 		goto err;
    334 	}
    335 
    336 	if (isreg) {
    337 		setfile(out, &sb);
    338 
    339 		if (unlink(in))
    340 			cwarn("%s", in);
    341 	}
    342 	return;
    343 
    344 err:	if (ofp) {
    345 		if (oreg)
    346 			(void)unlink(out);
    347 		(void)fclose(ofp);
    348 	}
    349 	if (ifp)
    350 		(void)fclose(ifp);
    351 }
    352 
    353 void
    354 setfile(name, fs)
    355 	char *name;
    356 	register struct stat *fs;
    357 {
    358 	static struct timeval tv[2];
    359 
    360 	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
    361 
    362 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
    363 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
    364 	if (utimes(name, tv))
    365 		cwarn("utimes: %s", name);
    366 
    367 	/*
    368 	 * Changing the ownership probably won't succeed, unless we're root
    369 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
    370 	 * the mode; current BSD behavior is to remove all setuid bits on
    371 	 * chown.  If chown fails, lose setuid/setgid bits.
    372 	 */
    373 	if (chown(name, fs->st_uid, fs->st_gid)) {
    374 		if (errno != EPERM)
    375 			cwarn("chown: %s", name);
    376 		fs->st_mode &= ~(S_ISUID|S_ISGID);
    377 	}
    378 	if (chmod(name, fs->st_mode))
    379 		cwarn("chown: %s", name);
    380 
    381 	if (chflags(name, fs->st_flags))
    382 		cwarn("chflags: %s", name);
    383 }
    384 
    385 int
    386 permission(fname)
    387 	char *fname;
    388 {
    389 	int ch, first;
    390 
    391 	if (!isatty(fileno(stderr)))
    392 		return (0);
    393 	(void)fprintf(stderr, "overwrite %s? ", fname);
    394 	first = ch = getchar();
    395 	while (ch != '\n' && ch != EOF)
    396 		ch = getchar();
    397 	return (first == 'y');
    398 }
    399 
    400 void
    401 usage(iscompress)
    402 	int iscompress;
    403 {
    404 	if (iscompress)
    405 		(void)fprintf(stderr,
    406 		    "usage: compress [-cfv] [-b bits] [file ...]\n");
    407 	else
    408 		(void)fprintf(stderr,
    409 		    "usage: uncompress [-c] [-b bits] [file ...]\n");
    410 	exit(1);
    411 }
    412 
    413 void
    414 #if __STDC__
    415 cwarnx(const char *fmt, ...)
    416 #else
    417 cwarnx(fmt, va_alist)
    418 	int eval;
    419 	const char *fmt;
    420 	va_dcl
    421 #endif
    422 {
    423 	va_list ap;
    424 #if __STDC__
    425 	va_start(ap, fmt);
    426 #else
    427 	va_start(ap);
    428 #endif
    429 	vwarnx(fmt, ap);
    430 	va_end(ap);
    431 	eval = 1;
    432 }
    433 
    434 void
    435 #if __STDC__
    436 cwarn(const char *fmt, ...)
    437 #else
    438 cwarn(fmt, va_alist)
    439 	int eval;
    440 	const char *fmt;
    441 	va_dcl
    442 #endif
    443 {
    444 	va_list ap;
    445 #if __STDC__
    446 	va_start(ap, fmt);
    447 #else
    448 	va_start(ap);
    449 #endif
    450 	vwarn(fmt, ap);
    451 	va_end(ap);
    452 	eval = 1;
    453 }
    454