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compress.c revision 1.9 
      1 /*	$NetBSD: compress.c,v 1.9 1995/03/26 09:44:38 glass 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 1995/03/26 09:44:38 glass 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 	exit (eval);
    193 }
    194 
    195 void
    196 compress(in, out, bits)
    197 	char *in, *out;
    198 	int bits;
    199 {
    200 	register int nr;
    201 	struct stat isb, sb;
    202 	FILE *ifp, *ofp;
    203 	int exists, isreg, oreg;
    204 	u_char buf[1024];
    205 
    206 	exists = !stat(out, &sb);
    207 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    208 		return;
    209 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    210 
    211 	ifp = ofp = NULL;
    212 	if ((ifp = fopen(in, "r")) == NULL) {
    213 		cwarn("%s", in);
    214 		return;
    215 	}
    216 	if (stat(in, &isb)) {		/* DON'T FSTAT! */
    217 		cwarn("%s", in);
    218 		goto err;
    219 	}
    220 	if (!S_ISREG(isb.st_mode))
    221 		isreg = 0;
    222 
    223 	if ((ofp = zopen(out, "w", bits)) == NULL) {
    224 		cwarn("%s", out);
    225 		goto err;
    226 	}
    227 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    228 		if (fwrite(buf, 1, nr, ofp) != nr) {
    229 			cwarn("%s", out);
    230 			goto err;
    231 		}
    232 
    233 	if (ferror(ifp) || fclose(ifp)) {
    234 		cwarn("%s", in);
    235 		goto err;
    236 	}
    237 	ifp = NULL;
    238 
    239 	if (fclose(ofp)) {
    240 		cwarn("%s", out);
    241 		goto err;
    242 	}
    243 	ofp = NULL;
    244 
    245 	if (isreg) {
    246 		if (stat(out, &sb)) {
    247 			cwarn("%s", out);
    248 			goto err;
    249 		}
    250 
    251 		if (!force && sb.st_size >= isb.st_size) {
    252 			if (verbose)
    253 		(void)printf("%s: file would grow; left unmodified\n", in);
    254 			if (unlink(out))
    255 				cwarn("%s", out);
    256 			goto err;
    257 		}
    258 
    259 		setfile(out, &isb);
    260 
    261 		if (unlink(in))
    262 			cwarn("%s", in);
    263 
    264 		if (verbose) {
    265 			(void)printf("%s: ", out);
    266 			if (isb.st_size > sb.st_size)
    267 				(void)printf("%.0f%% compression\n",
    268 				    ((float)sb.st_size / isb.st_size) * 100.0);
    269 			else
    270 				(void)printf("%.0f%% expansion\n",
    271 				    ((float)isb.st_size / sb.st_size) * 100.0);
    272 		}
    273 	}
    274 	return;
    275 
    276 err:	if (ofp) {
    277 		if (oreg)
    278 			(void)unlink(out);
    279 		(void)fclose(ofp);
    280 	}
    281 	if (ifp)
    282 		(void)fclose(ifp);
    283 }
    284 
    285 void
    286 decompress(in, out, bits)
    287 	char *in, *out;
    288 	int bits;
    289 {
    290 	register int nr;
    291 	struct stat sb;
    292 	FILE *ifp, *ofp;
    293 	int exists, isreg, oreg;
    294 	u_char buf[1024];
    295 
    296 	exists = !stat(out, &sb);
    297 	if (!force && exists && S_ISREG(sb.st_mode) && !permission(out))
    298 		return;
    299 	isreg = oreg = !exists || S_ISREG(sb.st_mode);
    300 
    301 	ifp = ofp = NULL;
    302 	if ((ofp = fopen(out, "w")) == NULL) {
    303 		cwarn("%s", out);
    304 		return;
    305 	}
    306 
    307 	if ((ifp = zopen(in, "r", bits)) == NULL) {
    308 		cwarn("%s", in);
    309 		goto err;
    310 	}
    311 	if (stat(in, &sb)) {
    312 		cwarn("%s", in);
    313 		goto err;
    314 	}
    315 	if (!S_ISREG(sb.st_mode))
    316 		isreg = 0;
    317 
    318 	while ((nr = fread(buf, 1, sizeof(buf), ifp)) != 0)
    319 		if (fwrite(buf, 1, nr, ofp) != nr) {
    320 			cwarn("%s", out);
    321 			goto err;
    322 		}
    323 
    324 	if (ferror(ifp) || fclose(ifp)) {
    325 		cwarn("%s", in);
    326 		goto err;
    327 	}
    328 	ifp = NULL;
    329 
    330 	if (fclose(ofp)) {
    331 		cwarn("%s", out);
    332 		goto err;
    333 	}
    334 
    335 	if (isreg) {
    336 		setfile(out, &sb);
    337 
    338 		if (unlink(in))
    339 			cwarn("%s", in);
    340 	}
    341 	return;
    342 
    343 err:	if (ofp) {
    344 		if (oreg)
    345 			(void)unlink(out);
    346 		(void)fclose(ofp);
    347 	}
    348 	if (ifp)
    349 		(void)fclose(ifp);
    350 }
    351 
    352 void
    353 setfile(name, fs)
    354 	char *name;
    355 	register struct stat *fs;
    356 {
    357 	static struct timeval tv[2];
    358 
    359 	fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;
    360 
    361 	TIMESPEC_TO_TIMEVAL(&tv[0], &fs->st_atimespec);
    362 	TIMESPEC_TO_TIMEVAL(&tv[1], &fs->st_mtimespec);
    363 	if (utimes(name, tv))
    364 		cwarn("utimes: %s", name);
    365 
    366 	/*
    367 	 * Changing the ownership probably won't succeed, unless we're root
    368 	 * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
    369 	 * the mode; current BSD behavior is to remove all setuid bits on
    370 	 * chown.  If chown fails, lose setuid/setgid bits.
    371 	 */
    372 	if (chown(name, fs->st_uid, fs->st_gid)) {
    373 		if (errno != EPERM)
    374 			cwarn("chown: %s", name);
    375 		fs->st_mode &= ~(S_ISUID|S_ISGID);
    376 	}
    377 	if (chmod(name, fs->st_mode))
    378 		cwarn("chown: %s", name);
    379 
    380 	if (chflags(name, fs->st_flags))
    381 		cwarn("chflags: %s", name);
    382 }
    383 
    384 int
    385 permission(fname)
    386 	char *fname;
    387 {
    388 	int ch, first;
    389 
    390 	if (!isatty(fileno(stderr)))
    391 		return (0);
    392 	(void)fprintf(stderr, "overwrite %s? ", fname);
    393 	first = ch = getchar();
    394 	while (ch != '\n' && ch != EOF)
    395 		ch = getchar();
    396 	return (first == 'y');
    397 }
    398 
    399 void
    400 usage(iscompress)
    401 	int iscompress;
    402 {
    403 	if (iscompress)
    404 		(void)fprintf(stderr,
    405 		    "usage: compress [-cfv] [-b bits] [file ...]\n");
    406 	else
    407 		(void)fprintf(stderr,
    408 		    "usage: uncompress [-c] [-b bits] [file ...]\n");
    409 	exit(1);
    410 }
    411 
    412 void
    413 #if __STDC__
    414 cwarnx(const char *fmt, ...)
    415 #else
    416 cwarnx(fmt, va_alist)
    417 	int eval;
    418 	const char *fmt;
    419 	va_dcl
    420 #endif
    421 {
    422 	va_list ap;
    423 #if __STDC__
    424 	va_start(ap, fmt);
    425 #else
    426 	va_start(ap);
    427 #endif
    428 	vwarnx(fmt, ap);
    429 	va_end(ap);
    430 	eval = 1;
    431 }
    432 
    433 void
    434 #if __STDC__
    435 cwarn(const char *fmt, ...)
    436 #else
    437 cwarn(fmt, va_alist)
    438 	int eval;
    439 	const char *fmt;
    440 	va_dcl
    441 #endif
    442 {
    443 	va_list ap;
    444 #if __STDC__
    445 	va_start(ap, fmt);
    446 #else
    447 	va_start(ap);
    448 #endif
    449 	vwarn(fmt, ap);
    450 	va_end(ap);
    451 	eval = 1;
    452 }
    453