xref: /freebsd/usr.bin/patch/util.c (revision 38f0b757fd84d17d0fc24739a7cda160c4516d81)
1 /*-
2  * Copyright 1986, Larry Wall
3  *
4  * Redistribution and use in source and binary forms, with or without
5  * modification, are permitted provided that the following condition is met:
6  * 1. Redistributions of source code must retain the above copyright notice,
7  * this condition and the following disclaimer.
8  *
9  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
10  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
11  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
12  * DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
13  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
14  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
15  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
16  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
17  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
18  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
19  * SUCH DAMAGE.
20  *
21  * patch - a program to apply diffs to original files
22  *
23  * -C option added in 1998, original code by Marc Espie, based on FreeBSD
24  * behaviour
25  *
26  * $OpenBSD: util.c,v 1.35 2010/07/24 01:10:12 ray Exp $
27  * $FreeBSD$
28  */
29 
30 #include <sys/param.h>
31 #include <sys/stat.h>
32 
33 #include <ctype.h>
34 #include <errno.h>
35 #include <fcntl.h>
36 #include <libgen.h>
37 #include <paths.h>
38 #include <signal.h>
39 #include <stdarg.h>
40 #include <stdlib.h>
41 #include <stdio.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 #include "common.h"
46 #include "util.h"
47 #include "backupfile.h"
48 #include "pathnames.h"
49 
50 /* Rename a file, copying it if necessary. */
51 
52 int
53 move_file(const char *from, const char *to)
54 {
55 	int	fromfd;
56 	ssize_t	i;
57 
58 	/* to stdout? */
59 
60 	if (strEQ(to, "-")) {
61 #ifdef DEBUGGING
62 		if (debug & 4)
63 			say("Moving %s to stdout.\n", from);
64 #endif
65 		fromfd = open(from, O_RDONLY);
66 		if (fromfd < 0)
67 			pfatal("internal error, can't reopen %s", from);
68 		while ((i = read(fromfd, buf, buf_size)) > 0)
69 			if (write(STDOUT_FILENO, buf, i) != i)
70 				pfatal("write failed");
71 		close(fromfd);
72 		return 0;
73 	}
74 	if (backup_file(to) < 0) {
75 		say("Can't backup %s, output is in %s: %s\n", to, from,
76 		    strerror(errno));
77 		return -1;
78 	}
79 #ifdef DEBUGGING
80 	if (debug & 4)
81 		say("Moving %s to %s.\n", from, to);
82 #endif
83 	if (rename(from, to) < 0) {
84 		if (errno != EXDEV || copy_file(from, to) < 0) {
85 			say("Can't create %s, output is in %s: %s\n",
86 			    to, from, strerror(errno));
87 			return -1;
88 		}
89 	}
90 	return 0;
91 }
92 
93 /* Backup the original file.  */
94 
95 int
96 backup_file(const char *orig)
97 {
98 	struct stat	filestat;
99 	char		bakname[MAXPATHLEN], *s, *simplename;
100 	dev_t		orig_device;
101 	ino_t		orig_inode;
102 
103 	if (backup_type == none || stat(orig, &filestat) != 0)
104 		return 0;			/* nothing to do */
105 	/*
106 	 * If the user used zero prefixes or suffixes, then
107 	 * he doesn't want backups.  Yet we have to remove
108 	 * orig to break possible hardlinks.
109 	 */
110 	if ((origprae && *origprae == 0) || *simple_backup_suffix == 0) {
111 		unlink(orig);
112 		return 0;
113 	}
114 	orig_device = filestat.st_dev;
115 	orig_inode = filestat.st_ino;
116 
117 	if (origprae) {
118 		if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
119 		    strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
120 			fatal("filename %s too long for buffer\n", origprae);
121 	} else {
122 		if ((s = find_backup_file_name(orig)) == NULL)
123 			fatal("out of memory\n");
124 		if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
125 			fatal("filename %s too long for buffer\n", s);
126 		free(s);
127 	}
128 
129 	if ((simplename = strrchr(bakname, '/')) != NULL)
130 		simplename = simplename + 1;
131 	else
132 		simplename = bakname;
133 
134 	/*
135 	 * Find a backup name that is not the same file. Change the
136 	 * first lowercase char into uppercase; if that isn't
137 	 * sufficient, chop off the first char and try again.
138 	 */
139 	while (stat(bakname, &filestat) == 0 &&
140 	    orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
141 		/* Skip initial non-lowercase chars.  */
142 		for (s = simplename; *s && !islower((unsigned char)*s); s++)
143 			;
144 		if (*s)
145 			*s = toupper((unsigned char)*s);
146 		else
147 			memmove(simplename, simplename + 1,
148 			    strlen(simplename + 1) + 1);
149 	}
150 #ifdef DEBUGGING
151 	if (debug & 4)
152 		say("Moving %s to %s.\n", orig, bakname);
153 #endif
154 	if (rename(orig, bakname) < 0) {
155 		if (errno != EXDEV || copy_file(orig, bakname) < 0)
156 			return -1;
157 	}
158 	return 0;
159 }
160 
161 /*
162  * Copy a file.
163  */
164 int
165 copy_file(const char *from, const char *to)
166 {
167 	int	tofd, fromfd;
168 	ssize_t	i;
169 
170 	tofd = open(to, O_CREAT|O_TRUNC|O_WRONLY, 0666);
171 	if (tofd < 0)
172 		return -1;
173 	fromfd = open(from, O_RDONLY, 0);
174 	if (fromfd < 0)
175 		pfatal("internal error, can't reopen %s", from);
176 	while ((i = read(fromfd, buf, buf_size)) > 0)
177 		if (write(tofd, buf, i) != i)
178 			pfatal("write to %s failed", to);
179 	close(fromfd);
180 	close(tofd);
181 	return 0;
182 }
183 
184 /*
185  * Allocate a unique area for a string.
186  */
187 char *
188 savestr(const char *s)
189 {
190 	char	*rv;
191 
192 	if (!s)
193 		s = "Oops";
194 	rv = strdup(s);
195 	if (rv == NULL) {
196 		if (using_plan_a)
197 			out_of_mem = true;
198 		else
199 			fatal("out of memory\n");
200 	}
201 	return rv;
202 }
203 
204 /*
205  * Vanilla terminal output (buffered).
206  */
207 void
208 say(const char *fmt, ...)
209 {
210 	va_list	ap;
211 
212 	va_start(ap, fmt);
213 	vfprintf(stdout, fmt, ap);
214 	va_end(ap);
215 	fflush(stdout);
216 }
217 
218 /*
219  * Terminal output, pun intended.
220  */
221 void
222 fatal(const char *fmt, ...)
223 {
224 	va_list	ap;
225 
226 	va_start(ap, fmt);
227 	fprintf(stderr, "patch: **** ");
228 	vfprintf(stderr, fmt, ap);
229 	va_end(ap);
230 	my_exit(2);
231 }
232 
233 /*
234  * Say something from patch, something from the system, then silence . . .
235  */
236 void
237 pfatal(const char *fmt, ...)
238 {
239 	va_list	ap;
240 	int	errnum = errno;
241 
242 	fprintf(stderr, "patch: **** ");
243 	va_start(ap, fmt);
244 	vfprintf(stderr, fmt, ap);
245 	va_end(ap);
246 	fprintf(stderr, ": %s\n", strerror(errnum));
247 	my_exit(2);
248 }
249 
250 /*
251  * Get a response from the user via /dev/tty
252  */
253 void
254 ask(const char *fmt, ...)
255 {
256 	va_list	ap;
257 	ssize_t	nr = 0;
258 	static	int ttyfd = -1;
259 
260 	va_start(ap, fmt);
261 	vfprintf(stdout, fmt, ap);
262 	va_end(ap);
263 	fflush(stdout);
264 	if (ttyfd < 0)
265 		ttyfd = open(_PATH_TTY, O_RDONLY);
266 	if (ttyfd >= 0) {
267 		if ((nr = read(ttyfd, buf, buf_size)) > 0 &&
268 		    buf[nr - 1] == '\n')
269 			buf[nr - 1] = '\0';
270 	}
271 	if (ttyfd < 0 || nr <= 0) {
272 		/* no tty or error reading, pretend user entered 'return' */
273 		putchar('\n');
274 		buf[0] = '\0';
275 	}
276 }
277 
278 /*
279  * How to handle certain events when not in a critical region.
280  */
281 void
282 set_signals(int reset)
283 {
284 	static sig_t	hupval, intval;
285 
286 	if (!reset) {
287 		hupval = signal(SIGHUP, SIG_IGN);
288 		if (hupval != SIG_IGN)
289 			hupval = my_exit;
290 		intval = signal(SIGINT, SIG_IGN);
291 		if (intval != SIG_IGN)
292 			intval = my_exit;
293 	}
294 	signal(SIGHUP, hupval);
295 	signal(SIGINT, intval);
296 }
297 
298 /*
299  * How to handle certain events when in a critical region.
300  */
301 void
302 ignore_signals(void)
303 {
304 	signal(SIGHUP, SIG_IGN);
305 	signal(SIGINT, SIG_IGN);
306 }
307 
308 /*
309  * Make sure we'll have the directories to create a file. If `striplast' is
310  * true, ignore the last element of `filename'.
311  */
312 
313 void
314 makedirs(const char *filename, bool striplast)
315 {
316 	char	*tmpbuf;
317 
318 	if ((tmpbuf = strdup(filename)) == NULL)
319 		fatal("out of memory\n");
320 
321 	if (striplast) {
322 		char	*s = strrchr(tmpbuf, '/');
323 		if (s == NULL) {
324 			free(tmpbuf);
325 			return;	/* nothing to be done */
326 		}
327 		*s = '\0';
328 	}
329 	if (mkpath(tmpbuf) != 0)
330 		pfatal("creation of %s failed", tmpbuf);
331 	free(tmpbuf);
332 }
333 
334 /*
335  * Make filenames more reasonable.
336  */
337 char *
338 fetchname(const char *at, bool *exists, int strip_leading)
339 {
340 	char		*fullname, *name, *t;
341 	int		sleading, tab;
342 	struct stat	filestat;
343 
344 	if (at == NULL || *at == '\0')
345 		return NULL;
346 	while (isspace((unsigned char)*at))
347 		at++;
348 #ifdef DEBUGGING
349 	if (debug & 128)
350 		say("fetchname %s %d\n", at, strip_leading);
351 #endif
352 	/* So files can be created by diffing against /dev/null.  */
353 	if (strnEQ(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL) - 1))
354 		return NULL;
355 	name = fullname = t = savestr(at);
356 
357 	tab = strchr(t, '\t') != NULL;
358 	/* Strip off up to `strip_leading' path components and NUL terminate. */
359 	for (sleading = strip_leading; *t != '\0' && ((tab && *t != '\t') ||
360 	    !isspace((unsigned char)*t)); t++) {
361 		if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
362 			if (--sleading >= 0)
363 				name = t + 1;
364 	}
365 	*t = '\0';
366 
367 	/*
368 	 * If no -p option was given (957 is the default value!), we were
369 	 * given a relative pathname, and the leading directories that we
370 	 * just stripped off all exist, put them back on.
371 	 */
372 	if (strip_leading == 957 && name != fullname && *fullname != '/') {
373 		name[-1] = '\0';
374 		if (stat(fullname, &filestat) == 0 && S_ISDIR(filestat.st_mode)) {
375 			name[-1] = '/';
376 			name = fullname;
377 		}
378 	}
379 	name = savestr(name);
380 	free(fullname);
381 
382 	*exists = stat(name, &filestat) == 0;
383 	return name;
384 }
385 
386 /*
387  * Takes the name returned by fetchname and looks in RCS/SCCS directories
388  * for a checked in version.
389  */
390 char *
391 checked_in(char *file)
392 {
393 	char		*filebase, *filedir, tmpbuf[MAXPATHLEN];
394 	struct stat	filestat;
395 
396 	filebase = basename(file);
397 	filedir = dirname(file);
398 
399 #define try(f, a1, a2, a3) \
400 (snprintf(tmpbuf, sizeof tmpbuf, f, a1, a2, a3), stat(tmpbuf, &filestat) == 0)
401 
402 	if (try("%s/RCS/%s%s", filedir, filebase, RCSSUFFIX) ||
403 	    try("%s/RCS/%s%s", filedir, filebase, "") ||
404 	    try("%s/%s%s", filedir, filebase, RCSSUFFIX) ||
405 	    try("%s/SCCS/%s%s", filedir, SCCSPREFIX, filebase) ||
406 	    try("%s/%s%s", filedir, SCCSPREFIX, filebase))
407 		return file;
408 
409 	return NULL;
410 }
411 
412 void
413 version(void)
414 {
415 	fprintf(stderr, "patch 2.0-12u10 FreeBSD\n");
416 	my_exit(EXIT_SUCCESS);
417 }
418 
419 /*
420  * Exit with cleanup.
421  */
422 void
423 my_exit(int status)
424 {
425 	unlink(TMPINNAME);
426 	if (!toutkeep)
427 		unlink(TMPOUTNAME);
428 	if (!trejkeep)
429 		unlink(TMPREJNAME);
430 	unlink(TMPPATNAME);
431 	exit(status);
432 }
433