xref: /freebsd/usr.bin/diff/diff.c (revision 98dc8da58c698aed1843a912c7c5f5b9dfef3656)
1  /*	$OpenBSD: diff.c,v 1.65 2015/12/29 19:04:46 gsoares Exp $	*/
2  
3  /*
4   * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
5   *
6   * Permission to use, copy, modify, and distribute this software for any
7   * purpose with or without fee is hereby granted, provided that the above
8   * copyright notice and this permission notice appear in all copies.
9   *
10   * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11   * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12   * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13   * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14   * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15   * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16   * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17   *
18   * Sponsored in part by the Defense Advanced Research Projects
19   * Agency (DARPA) and Air Force Research Laboratory, Air Force
20   * Materiel Command, USAF, under agreement number F39502-99-1-0512.
21   */
22  
23  #include <sys/cdefs.h>
24  __FBSDID("$FreeBSD$");
25  
26  #include <sys/stat.h>
27  
28  #include <ctype.h>
29  #include <err.h>
30  #include <getopt.h>
31  #include <stdlib.h>
32  #include <stdio.h>
33  #include <string.h>
34  #include <unistd.h>
35  #include <limits.h>
36  
37  #include "diff.h"
38  #include "xmalloc.h"
39  
40  int	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag;
41  int	 diff_format, diff_context, status, ignore_file_case;
42  int	 tabsize = 8;
43  char	*start, *ifdefname, *diffargs, *label[2], *ignore_pats;
44  char	*group_format = NULL;
45  struct stat stb1, stb2;
46  struct excludes *excludes_list;
47  regex_t	 ignore_re;
48  
49  #define	OPTIONS	"0123456789aBbC:cdD:efHhI:iL:lnNPpqrS:sTtU:uwX:x:"
50  enum {
51  	OPT_TSIZE = CHAR_MAX + 1,
52  	OPT_STRIPCR,
53  	OPT_IGN_FN_CASE,
54  	OPT_NO_IGN_FN_CASE,
55  	OPT_NORMAL,
56  	OPT_HORIZON_LINES,
57  	OPT_CHANGED_GROUP_FORMAT,
58  };
59  
60  static struct option longopts[] = {
61  	{ "text",			no_argument,		0,	'a' },
62  	{ "ignore-space-change",	no_argument,		0,	'b' },
63  	{ "context",			optional_argument,	0,	'C' },
64  	{ "ifdef",			required_argument,	0,	'D' },
65  	{ "minimal",			no_argument,		0,	'd' },
66  	{ "ed",				no_argument,		0,	'e' },
67  	{ "forward-ed",			no_argument,		0,	'f' },
68  	{ "speed-large-files",		no_argument,		NULL,	'H' },
69  	{ "ignore-blank-lines",		no_argument,		0,	'B' },
70  	{ "ignore-matching-lines",	required_argument,	0,	'I' },
71  	{ "ignore-case",		no_argument,		0,	'i' },
72  	{ "paginate",			no_argument,		NULL,	'l' },
73  	{ "label",			required_argument,	0,	'L' },
74  	{ "new-file",			no_argument,		0,	'N' },
75  	{ "rcs",			no_argument,		0,	'n' },
76  	{ "unidirectional-new-file",	no_argument,		0,	'P' },
77  	{ "show-c-function",		no_argument,		0,	'p' },
78  	{ "brief",			no_argument,		0,	'q' },
79  	{ "recursive",			no_argument,		0,	'r' },
80  	{ "report-identical-files",	no_argument,		0,	's' },
81  	{ "starting-file",		required_argument,	0,	'S' },
82  	{ "expand-tabs",		no_argument,		0,	't' },
83  	{ "initial-tab",		no_argument,		0,	'T' },
84  	{ "unified",			optional_argument,	0,	'U' },
85  	{ "ignore-all-space",		no_argument,		0,	'w' },
86  	{ "exclude",			required_argument,	0,	'x' },
87  	{ "exclude-from",		required_argument,	0,	'X' },
88  	{ "ignore-file-name-case",	no_argument,		NULL,	OPT_IGN_FN_CASE },
89  	{ "horizon-lines",		required_argument,	NULL,	OPT_HORIZON_LINES },
90  	{ "no-ignore-file-name-case",	no_argument,		NULL,	OPT_NO_IGN_FN_CASE },
91  	{ "normal",			no_argument,		NULL,	OPT_NORMAL },
92  	{ "strip-trailing-cr",		no_argument,		NULL,	OPT_STRIPCR },
93  	{ "tabsize",			optional_argument,	NULL,	OPT_TSIZE },
94  	{ "changed-group-format",	required_argument,	NULL,	OPT_CHANGED_GROUP_FORMAT},
95  	{ NULL,				0,			0,	'\0'}
96  };
97  
98  void usage(void) __dead2;
99  void push_excludes(char *);
100  void push_ignore_pats(char *);
101  void read_excludes_file(char *file);
102  void set_argstr(char **, char **);
103  
104  int
105  main(int argc, char **argv)
106  {
107  	const char *errstr = NULL;
108  	char *ep, **oargv;
109  	long  l;
110  	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
111  
112  	oargv = argv;
113  	gotstdin = 0;
114  	dflags = 0;
115  	lastch = '\0';
116  	prevoptind = 1;
117  	newarg = 1;
118  	diff_context = 3;
119  	diff_format = 0;
120  	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
121  		switch (ch) {
122  		case '0': case '1': case '2': case '3': case '4':
123  		case '5': case '6': case '7': case '8': case '9':
124  			if (newarg)
125  				usage();	/* disallow -[0-9]+ */
126  			else if (lastch == 'c' || lastch == 'u')
127  				diff_context = 0;
128  			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
129  				usage();
130  			diff_context = (diff_context * 10) + (ch - '0');
131  			break;
132  		case 'a':
133  			dflags |= D_FORCEASCII;
134  			break;
135  		case 'b':
136  			dflags |= D_FOLDBLANKS;
137  			break;
138  		case 'C':
139  		case 'c':
140  			cflag = 1;
141  			diff_format = D_CONTEXT;
142  			if (optarg != NULL) {
143  				l = strtol(optarg, &ep, 10);
144  				if (*ep != '\0' || l < 0 || l >= INT_MAX)
145  					usage();
146  				diff_context = (int)l;
147  			}
148  			break;
149  		case 'd':
150  			dflags |= D_MINIMAL;
151  			break;
152  		case 'D':
153  			diff_format = D_IFDEF;
154  			ifdefname = optarg;
155  			break;
156  		case 'e':
157  			diff_format = D_EDIT;
158  			break;
159  		case 'f':
160  			diff_format = D_REVERSE;
161  			break;
162  		case 'H':
163  			/* ignore but needed for compatibility with GNU diff */
164  			break;
165  		case 'h':
166  			/* silently ignore for backwards compatibility */
167  			break;
168  		case 'B':
169  			dflags |= D_SKIPBLANKLINES;
170  			break;
171  		case 'I':
172  			push_ignore_pats(optarg);
173  			break;
174  		case 'i':
175  			dflags |= D_IGNORECASE;
176  			break;
177  		case 'L':
178  			if (label[0] == NULL)
179  				label[0] = optarg;
180  			else if (label[1] == NULL)
181  				label[1] = optarg;
182  			else
183  				usage();
184  			break;
185  		case 'l':
186  			lflag = 1;
187  			break;
188  		case 'N':
189  			Nflag = 1;
190  			break;
191  		case 'n':
192  			diff_format = D_NREVERSE;
193  			break;
194  		case 'p':
195  			if (diff_format == 0)
196  				diff_format = D_CONTEXT;
197  			dflags |= D_PROTOTYPE;
198  			break;
199  		case 'P':
200  			Pflag = 1;
201  			break;
202  		case 'r':
203  			rflag = 1;
204  			break;
205  		case 'q':
206  			diff_format = D_BRIEF;
207  			break;
208  		case 'S':
209  			start = optarg;
210  			break;
211  		case 's':
212  			sflag = 1;
213  			break;
214  		case 'T':
215  			Tflag = 1;
216  			break;
217  		case 't':
218  			dflags |= D_EXPANDTABS;
219  			break;
220  		case 'U':
221  		case 'u':
222  			diff_format = D_UNIFIED;
223  			if (optarg != NULL) {
224  				l = strtol(optarg, &ep, 10);
225  				if (*ep != '\0' || l < 0 || l >= INT_MAX)
226  					usage();
227  				diff_context = (int)l;
228  			}
229  			break;
230  		case 'w':
231  			dflags |= D_IGNOREBLANKS;
232  			break;
233  		case 'X':
234  			read_excludes_file(optarg);
235  			break;
236  		case 'x':
237  			push_excludes(optarg);
238  			break;
239  		case OPT_CHANGED_GROUP_FORMAT:
240  			diff_format = D_GFORMAT;
241  			group_format = optarg;
242  			break;
243  		case OPT_HORIZON_LINES:
244  			break; /* XXX TODO for compatibility with GNU diff3 */
245  		case OPT_IGN_FN_CASE:
246  			ignore_file_case = 1;
247  			break;
248  		case OPT_NO_IGN_FN_CASE:
249  			ignore_file_case = 0;
250  			break;
251  		case OPT_NORMAL:
252  			diff_format = D_NORMAL;
253  			break;
254  		case OPT_TSIZE:
255  			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
256  			if (errstr) {
257  				warnx("Invalid argument for tabsize");
258  				usage();
259  			}
260  			break;
261  		case OPT_STRIPCR:
262  			dflags |= D_STRIPCR;
263  			break;
264  		default:
265  			usage();
266  			break;
267  		}
268  		lastch = ch;
269  		newarg = optind != prevoptind;
270  		prevoptind = optind;
271  	}
272  	argc -= optind;
273  	argv += optind;
274  
275  #ifdef __OpenBSD__
276  	if (pledge("stdio rpath tmppath", NULL) == -1)
277  		err(2, "pledge");
278  #endif
279  
280  	/*
281  	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
282  	 * driver routine.  Both drivers use the contents of stb1 and stb2.
283  	 */
284  	if (argc != 2)
285  		usage();
286  	if (ignore_pats != NULL) {
287  		char buf[BUFSIZ];
288  		int error;
289  
290  		if ((error = regcomp(&ignore_re, ignore_pats,
291  				     REG_NEWLINE | REG_EXTENDED)) != 0) {
292  			regerror(error, &ignore_re, buf, sizeof(buf));
293  			if (*ignore_pats != '\0')
294  				errx(2, "%s: %s", ignore_pats, buf);
295  			else
296  				errx(2, "%s", buf);
297  		}
298  	}
299  	if (strcmp(argv[0], "-") == 0) {
300  		fstat(STDIN_FILENO, &stb1);
301  		gotstdin = 1;
302  	} else if (stat(argv[0], &stb1) != 0)
303  		err(2, "%s", argv[0]);
304  	if (strcmp(argv[1], "-") == 0) {
305  		fstat(STDIN_FILENO, &stb2);
306  		gotstdin = 1;
307  	} else if (stat(argv[1], &stb2) != 0)
308  		err(2, "%s", argv[1]);
309  	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
310  		errx(2, "can't compare - to a directory");
311  	set_argstr(oargv, argv);
312  	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
313  		if (diff_format == D_IFDEF)
314  			errx(2, "-D option not supported with directories");
315  		diffdir(argv[0], argv[1], dflags);
316  	} else {
317  		if (S_ISDIR(stb1.st_mode)) {
318  			argv[0] = splice(argv[0], argv[1]);
319  			if (stat(argv[0], &stb1) < 0)
320  				err(2, "%s", argv[0]);
321  		}
322  		if (S_ISDIR(stb2.st_mode)) {
323  			argv[1] = splice(argv[1], argv[0]);
324  			if (stat(argv[1], &stb2) < 0)
325  				err(2, "%s", argv[1]);
326  		}
327  		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
328  		    argv[1], "");
329  	}
330  	exit(status);
331  }
332  
333  void
334  set_argstr(char **av, char **ave)
335  {
336  	size_t argsize;
337  	char **ap;
338  
339  	argsize = 4 + *ave - *av + 1;
340  	diffargs = xmalloc(argsize);
341  	strlcpy(diffargs, "diff", argsize);
342  	for (ap = av + 1; ap < ave; ap++) {
343  		if (strcmp(*ap, "--") != 0) {
344  			strlcat(diffargs, " ", argsize);
345  			strlcat(diffargs, *ap, argsize);
346  		}
347  	}
348  }
349  
350  /*
351   * Read in an excludes file and push each line.
352   */
353  void
354  read_excludes_file(char *file)
355  {
356  	FILE *fp;
357  	char *buf, *pattern;
358  	size_t len;
359  
360  	if (strcmp(file, "-") == 0)
361  		fp = stdin;
362  	else if ((fp = fopen(file, "r")) == NULL)
363  		err(2, "%s", file);
364  	while ((buf = fgetln(fp, &len)) != NULL) {
365  		if (buf[len - 1] == '\n')
366  			len--;
367  		if ((pattern = strndup(buf, len)) == NULL)
368  			err(2, "xstrndup");
369  		push_excludes(pattern);
370  	}
371  	if (strcmp(file, "-") != 0)
372  		fclose(fp);
373  }
374  
375  /*
376   * Push a pattern onto the excludes list.
377   */
378  void
379  push_excludes(char *pattern)
380  {
381  	struct excludes *entry;
382  
383  	entry = xmalloc(sizeof(*entry));
384  	entry->pattern = pattern;
385  	entry->next = excludes_list;
386  	excludes_list = entry;
387  }
388  
389  void
390  push_ignore_pats(char *pattern)
391  {
392  	size_t len;
393  
394  	if (ignore_pats == NULL)
395  		ignore_pats = xstrdup(pattern);
396  	else {
397  		/* old + "|" + new + NUL */
398  		len = strlen(ignore_pats) + strlen(pattern) + 2;
399  		ignore_pats = xreallocarray(ignore_pats, 1, len);
400  		strlcat(ignore_pats, "|", len);
401  		strlcat(ignore_pats, pattern, len);
402  	}
403  }
404  
405  void
406  print_only(const char *path, size_t dirlen, const char *entry)
407  {
408  	if (dirlen > 1)
409  		dirlen--;
410  	printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
411  }
412  
413  void
414  print_status(int val, char *path1, char *path2, const char *entry)
415  {
416  	switch (val) {
417  	case D_BINARY:
418  		printf("Binary files %s%s and %s%s differ\n",
419  		    path1, entry, path2, entry);
420  		break;
421  	case D_DIFFER:
422  		if (diff_format == D_BRIEF)
423  			printf("Files %s%s and %s%s differ\n",
424  			    path1, entry, path2, entry);
425  		break;
426  	case D_SAME:
427  		if (sflag)
428  			printf("Files %s%s and %s%s are identical\n",
429  			    path1, entry, path2, entry);
430  		break;
431  	case D_MISMATCH1:
432  		printf("File %s%s is a directory while file %s%s is a regular file\n",
433  		    path1, entry, path2, entry);
434  		break;
435  	case D_MISMATCH2:
436  		printf("File %s%s is a regular file while file %s%s is a directory\n",
437  		    path1, entry, path2, entry);
438  		break;
439  	case D_SKIPPED1:
440  		printf("File %s%s is not a regular file or directory and was skipped\n",
441  		    path1, entry);
442  		break;
443  	case D_SKIPPED2:
444  		printf("File %s%s is not a regular file or directory and was skipped\n",
445  		    path2, entry);
446  		break;
447  	}
448  }
449  
450  void
451  usage(void)
452  {
453  	(void)fprintf(stderr,
454  	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
455  	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
456  	    "            [-I pattern] [-L label] file1 file2\n"
457  	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
458  	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
459  	    "            -C number file1 file2\n"
460  	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
461  	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
462  	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
463  	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
464  	    "            -U number file1 file2\n"
465  	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
466  	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
467  	    "            [-S name] [-X file] [-x pattern] dir1 dir2\n");
468  
469  	exit(2);
470  }
471