xref: /freebsd/usr.bin/patch/util.c (revision 783d3ff6d7fae619db8a7990b8a6387de0c677b5)
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  */
28 
29 #include <sys/stat.h>
30 
31 #include <ctype.h>
32 #include <errno.h>
33 #include <fcntl.h>
34 #include <libgen.h>
35 #include <limits.h>
36 #include <paths.h>
37 #include <signal.h>
38 #include <stdarg.h>
39 #include <stdlib.h>
40 #include <stdio.h>
41 #include <string.h>
42 #include <unistd.h>
43 
44 #include "common.h"
45 #include "util.h"
46 #include "backupfile.h"
47 #include "pathnames.h"
48 
49 /* Rename a file, copying it if necessary. */
50 
51 int
52 move_file(const char *from, const char *to)
53 {
54 	int	fromfd;
55 	ssize_t	i;
56 
57 	/* to stdout? */
58 
59 	if (strEQ(to, "-")) {
60 #ifdef DEBUGGING
61 		if (debug & 4)
62 			say("Moving %s to stdout.\n", from);
63 #endif
64 		fromfd = open(from, O_RDONLY);
65 		if (fromfd < 0)
66 			pfatal("internal error, can't reopen %s", from);
67 		while ((i = read(fromfd, buf, buf_size)) > 0)
68 			if (write(STDOUT_FILENO, buf, i) != i)
69 				pfatal("write failed");
70 		close(fromfd);
71 		return 0;
72 	}
73 	if (backup_file(to) < 0) {
74 		say("Can't backup %s, output is in %s: %s\n", to, from,
75 		    strerror(errno));
76 		return -1;
77 	}
78 #ifdef DEBUGGING
79 	if (debug & 4)
80 		say("Moving %s to %s.\n", from, to);
81 #endif
82 	if (rename(from, to) < 0) {
83 		if (errno != EXDEV || copy_file(from, to) < 0) {
84 			say("Can't create %s, output is in %s: %s\n",
85 			    to, from, strerror(errno));
86 			return -1;
87 		}
88 	}
89 	return 0;
90 }
91 
92 /* Backup the original file.  */
93 
94 int
95 backup_file(const char *orig)
96 {
97 	struct stat	filestat;
98 	char		bakname[PATH_MAX], *s, *simplename;
99 	dev_t		orig_device;
100 	ino_t		orig_inode;
101 
102 	if (backup_type == none || stat(orig, &filestat) != 0)
103 		return 0;			/* nothing to do */
104 	/*
105 	 * If the user used zero prefixes or suffixes, then
106 	 * he doesn't want backups.  Yet we have to remove
107 	 * orig to break possible hardlinks.
108 	 */
109 	if ((origprae && *origprae == 0) || *simple_backup_suffix == 0) {
110 		unlink(orig);
111 		return 0;
112 	}
113 	orig_device = filestat.st_dev;
114 	orig_inode = filestat.st_ino;
115 
116 	if (origprae) {
117 		if (strlcpy(bakname, origprae, sizeof(bakname)) >= sizeof(bakname) ||
118 		    strlcat(bakname, orig, sizeof(bakname)) >= sizeof(bakname))
119 			fatal("filename %s too long for buffer\n", origprae);
120 	} else {
121 		if ((s = find_backup_file_name(orig)) == NULL)
122 			fatal("out of memory\n");
123 		if (strlcpy(bakname, s, sizeof(bakname)) >= sizeof(bakname))
124 			fatal("filename %s too long for buffer\n", s);
125 		free(s);
126 	}
127 
128 	if ((simplename = strrchr(bakname, '/')) != NULL)
129 		simplename = simplename + 1;
130 	else
131 		simplename = bakname;
132 
133 	/*
134 	 * Find a backup name that is not the same file. Change the
135 	 * first lowercase char into uppercase; if that isn't
136 	 * sufficient, chop off the first char and try again.
137 	 */
138 	while (stat(bakname, &filestat) == 0 &&
139 	    orig_device == filestat.st_dev && orig_inode == filestat.st_ino) {
140 		/* Skip initial non-lowercase chars.  */
141 		for (s = simplename; *s && !islower((unsigned char)*s); s++)
142 			;
143 		if (*s)
144 			*s = toupper((unsigned char)*s);
145 		else
146 			memmove(simplename, simplename + 1,
147 			    strlen(simplename + 1) + 1);
148 	}
149 #ifdef DEBUGGING
150 	if (debug & 4)
151 		say("Moving %s to %s.\n", orig, bakname);
152 #endif
153 	if (rename(orig, bakname) < 0) {
154 		if (errno != EXDEV || copy_file(orig, bakname) < 0)
155 			return -1;
156 	}
157 	return 0;
158 }
159 
160 /*
161  * Copy a file.
162  */
163 int
164 copy_file(const char *from, const char *to)
165 {
166 	int	tofd, fromfd;
167 	ssize_t	i;
168 
169 	tofd = open(to, O_CREAT|O_TRUNC|O_WRONLY, 0666);
170 	if (tofd < 0)
171 		return -1;
172 	fromfd = open(from, O_RDONLY, 0);
173 	if (fromfd < 0)
174 		pfatal("internal error, can't reopen %s", from);
175 	while ((i = read(fromfd, buf, buf_size)) > 0)
176 		if (write(tofd, buf, i) != i)
177 			pfatal("write to %s failed", to);
178 	close(fromfd);
179 	close(tofd);
180 	return 0;
181 }
182 
183 /*
184  * Allocate a unique area for a string.
185  */
186 char *
187 savestr(const char *s)
188 {
189 	char	*rv;
190 
191 	if (!s)
192 		s = "Oops";
193 	rv = strdup(s);
194 	if (rv == NULL) {
195 		if (using_plan_a)
196 			out_of_mem = true;
197 		else
198 			fatal("out of memory\n");
199 	}
200 	return rv;
201 }
202 
203 /*
204  * Allocate a unique area for a string.  Call fatal if out of memory.
205  */
206 char *
207 xstrdup(const char *s)
208 {
209 	char	*rv;
210 
211 	if (!s)
212 		s = "Oops";
213 	rv = strdup(s);
214 	if (rv == NULL)
215 		fatal("out of memory\n");
216 	return rv;
217 }
218 
219 /*
220  * Vanilla terminal output (buffered).
221  */
222 void
223 say(const char *fmt, ...)
224 {
225 	va_list	ap;
226 
227 	va_start(ap, fmt);
228 	vfprintf(stdout, fmt, ap);
229 	va_end(ap);
230 	fflush(stdout);
231 }
232 
233 /*
234  * Terminal output, pun intended.
235  */
236 void
237 fatal(const char *fmt, ...)
238 {
239 	va_list	ap;
240 
241 	va_start(ap, fmt);
242 	fprintf(stderr, "patch: **** ");
243 	vfprintf(stderr, fmt, ap);
244 	va_end(ap);
245 	my_exit(2);
246 }
247 
248 /*
249  * Say something from patch, something from the system, then silence . . .
250  */
251 void
252 pfatal(const char *fmt, ...)
253 {
254 	va_list	ap;
255 	int	errnum = errno;
256 
257 	fprintf(stderr, "patch: **** ");
258 	va_start(ap, fmt);
259 	vfprintf(stderr, fmt, ap);
260 	va_end(ap);
261 	fprintf(stderr, ": %s\n", strerror(errnum));
262 	my_exit(2);
263 }
264 
265 /*
266  * Get a response from the user via /dev/tty
267  */
268 void
269 ask(const char *fmt, ...)
270 {
271 	va_list	ap;
272 	ssize_t	nr = 0;
273 	static	int ttyfd = -1;
274 
275 	va_start(ap, fmt);
276 	vfprintf(stdout, fmt, ap);
277 	va_end(ap);
278 	fflush(stdout);
279 	if (ttyfd < 0)
280 		ttyfd = open(_PATH_TTY, O_RDONLY);
281 	if (ttyfd >= 0) {
282 		if ((nr = read(ttyfd, buf, buf_size)) > 0 &&
283 		    buf[nr - 1] == '\n')
284 			buf[nr - 1] = '\0';
285 	}
286 	if (ttyfd < 0 || nr <= 0) {
287 		/* no tty or error reading, pretend user entered 'return' */
288 		putchar('\n');
289 		buf[0] = '\0';
290 	}
291 }
292 
293 /*
294  * How to handle certain events when not in a critical region.
295  */
296 void
297 set_signals(int reset)
298 {
299 	static sig_t	hupval, intval;
300 
301 	if (!reset) {
302 		hupval = signal(SIGHUP, SIG_IGN);
303 		if (hupval != SIG_IGN)
304 			hupval = my_exit;
305 		intval = signal(SIGINT, SIG_IGN);
306 		if (intval != SIG_IGN)
307 			intval = my_exit;
308 	}
309 	signal(SIGHUP, hupval);
310 	signal(SIGINT, intval);
311 }
312 
313 /*
314  * How to handle certain events when in a critical region.
315  */
316 void
317 ignore_signals(void)
318 {
319 	signal(SIGHUP, SIG_IGN);
320 	signal(SIGINT, SIG_IGN);
321 }
322 
323 /*
324  * Make sure we'll have the directories to create a file. If `striplast' is
325  * true, ignore the last element of `filename'.
326  */
327 
328 void
329 makedirs(const char *filename, bool striplast)
330 {
331 	char	*tmpbuf;
332 
333 	if ((tmpbuf = strdup(filename)) == NULL)
334 		fatal("out of memory\n");
335 
336 	if (striplast) {
337 		char	*s = strrchr(tmpbuf, '/');
338 		if (s == NULL) {
339 			free(tmpbuf);
340 			return;	/* nothing to be done */
341 		}
342 		*s = '\0';
343 	}
344 	if (mkpath(tmpbuf) != 0)
345 		pfatal("creation of %s failed", tmpbuf);
346 	free(tmpbuf);
347 }
348 
349 /*
350  * Make filenames more reasonable.
351  */
352 char *
353 fetchname(const char *at, bool *exists, int strip_leading)
354 {
355 	char		*fullname, *name, *t;
356 	int		sleading, tab;
357 	struct stat	filestat;
358 
359 	if (at == NULL || *at == '\0')
360 		return NULL;
361 	while (isspace((unsigned char)*at))
362 		at++;
363 #ifdef DEBUGGING
364 	if (debug & 128)
365 		say("fetchname %s %d\n", at, strip_leading);
366 #endif
367 	/* So files can be created by diffing against /dev/null.  */
368 	if (strnEQ(at, _PATH_DEVNULL, sizeof(_PATH_DEVNULL) - 1)) {
369 		*exists = true;
370 		return NULL;
371 	}
372 	name = fullname = t = savestr(at);
373 
374 	tab = strchr(t, '\t') != NULL;
375 	/* Strip off up to `strip_leading' path components and NUL terminate. */
376 	for (sleading = strip_leading; *t != '\0' && ((tab && *t != '\t') ||
377 	    !isspace((unsigned char)*t)); t++) {
378 		if (t[0] == '/' && t[1] != '/' && t[1] != '\0')
379 			if (--sleading >= 0)
380 				name = t + 1;
381 	}
382 	*t = '\0';
383 
384 	/*
385 	 * If no -p option was given (957 is the default value!), we were
386 	 * given a relative pathname, and the leading directories that we
387 	 * just stripped off all exist, put them back on.
388 	 */
389 	if (strip_leading == 957 && name != fullname && *fullname != '/') {
390 		name[-1] = '\0';
391 		if (stat(fullname, &filestat) == 0 && S_ISDIR(filestat.st_mode)) {
392 			name[-1] = '/';
393 			name = fullname;
394 		}
395 	}
396 	name = savestr(name);
397 	free(fullname);
398 
399 	*exists = stat(name, &filestat) == 0;
400 	return name;
401 }
402 
403 void
404 version(void)
405 {
406 	printf("patch 2.0-12u11 FreeBSD\n");
407 	my_exit(EXIT_SUCCESS);
408 }
409 
410 /*
411  * Exit with cleanup.
412  */
413 void
414 my_exit(int status)
415 {
416 	unlink(TMPINNAME);
417 	if (!toutkeep)
418 		unlink(TMPOUTNAME);
419 	if (!trejkeep)
420 		unlink(TMPREJNAME);
421 	unlink(TMPPATNAME);
422 	exit(status);
423 }
424