xref: /freebsd/usr.bin/diff/diff.c (revision 2e3f49888ec8851bafb22011533217487764fdb0)
1 /*	$OpenBSD: diff.c,v 1.67 2019/06/28 13:35:00 deraadt 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 #include <sys/stat.h>
25 
26 #include <ctype.h>
27 #include <err.h>
28 #include <errno.h>
29 #include <getopt.h>
30 #include <stdlib.h>
31 #include <stdio.h>
32 #include <string.h>
33 #include <unistd.h>
34 #include <limits.h>
35 
36 #include "diff.h"
37 #include "xmalloc.h"
38 
39 static const char diff_version[] = "FreeBSD diff 20220309";
40 bool	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag;
41 bool	 ignore_file_case, suppress_common, color, noderef;
42 static bool help = false;
43 int	 diff_format, diff_context, status;
44 int	 tabsize = 8, width = 130;
45 static int	colorflag = COLORFLAG_NEVER;
46 char	*start, *ifdefname, *diffargs, *label[2];
47 char	*ignore_pats, *most_recent_pat;
48 char	*group_format = NULL;
49 const char	*add_code, *del_code;
50 struct stat stb1, stb2;
51 struct excludes *excludes_list;
52 regex_t	 ignore_re, most_recent_re;
53 
54 #define	OPTIONS	"0123456789aBbC:cdD:efF:HhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
55 enum {
56 	OPT_TSIZE = CHAR_MAX + 1,
57 	OPT_STRIPCR,
58 	OPT_IGN_FN_CASE,
59 	OPT_NO_IGN_FN_CASE,
60 	OPT_NORMAL,
61 	OPT_HELP,
62 	OPT_HORIZON_LINES,
63 	OPT_CHANGED_GROUP_FORMAT,
64 	OPT_SUPPRESS_COMMON,
65 	OPT_COLOR,
66 	OPT_NO_DEREFERENCE,
67 	OPT_VERSION,
68 };
69 
70 static struct option longopts[] = {
71 	{ "text",			no_argument,		0,	'a' },
72 	{ "ignore-space-change",	no_argument,		0,	'b' },
73 	{ "context",			optional_argument,	0,	'C' },
74 	{ "ifdef",			required_argument,	0,	'D' },
75 	{ "minimal",			no_argument,		0,	'd' },
76 	{ "ed",				no_argument,		0,	'e' },
77 	{ "forward-ed",			no_argument,		0,	'f' },
78 	{ "show-function-line",		required_argument,	0,	'F' },
79 	{ "speed-large-files",		no_argument,		NULL,	'H' },
80 	{ "ignore-blank-lines",		no_argument,		0,	'B' },
81 	{ "ignore-matching-lines",	required_argument,	0,	'I' },
82 	{ "ignore-case",		no_argument,		0,	'i' },
83 	{ "paginate",			no_argument,		NULL,	'l' },
84 	{ "label",			required_argument,	0,	'L' },
85 	{ "new-file",			no_argument,		0,	'N' },
86 	{ "rcs",			no_argument,		0,	'n' },
87 	{ "unidirectional-new-file",	no_argument,		0,	'P' },
88 	{ "show-c-function",		no_argument,		0,	'p' },
89 	{ "brief",			no_argument,		0,	'q' },
90 	{ "recursive",			no_argument,		0,	'r' },
91 	{ "report-identical-files",	no_argument,		0,	's' },
92 	{ "starting-file",		required_argument,	0,	'S' },
93 	{ "expand-tabs",		no_argument,		0,	't' },
94 	{ "initial-tab",		no_argument,		0,	'T' },
95 	{ "unified",			optional_argument,	0,	'U' },
96 	{ "ignore-all-space",		no_argument,		0,	'w' },
97 	{ "width",			required_argument,	0,	'W' },
98 	{ "exclude",			required_argument,	0,	'x' },
99 	{ "exclude-from",		required_argument,	0,	'X' },
100 	{ "side-by-side",		no_argument,		NULL,	'y' },
101 	{ "ignore-file-name-case",	no_argument,		NULL,	OPT_IGN_FN_CASE },
102 	{ "help",			no_argument,		NULL,	OPT_HELP},
103 	{ "horizon-lines",		required_argument,	NULL,	OPT_HORIZON_LINES },
104 	{ "no-dereference",		no_argument,		NULL,	OPT_NO_DEREFERENCE},
105 	{ "no-ignore-file-name-case",	no_argument,		NULL,	OPT_NO_IGN_FN_CASE },
106 	{ "normal",			no_argument,		NULL,	OPT_NORMAL },
107 	{ "strip-trailing-cr",		no_argument,		NULL,	OPT_STRIPCR },
108 	{ "tabsize",			required_argument,	NULL,	OPT_TSIZE },
109 	{ "changed-group-format",	required_argument,	NULL,	OPT_CHANGED_GROUP_FORMAT},
110 	{ "suppress-common-lines",	no_argument,		NULL,	OPT_SUPPRESS_COMMON },
111 	{ "color",			optional_argument,	NULL,	OPT_COLOR },
112 	{ "version",			no_argument,		NULL,	OPT_VERSION},
113 	{ NULL,				0,			0,	'\0'}
114 };
115 
116 static void checked_regcomp(char const *, regex_t *);
117 static void usage(void) __dead2;
118 static void conflicting_format(void) __dead2;
119 static void push_excludes(char *);
120 static void push_ignore_pats(char *);
121 static void read_excludes_file(char *file);
122 static void set_argstr(char **, char **);
123 static char *splice(char *, char *);
124 static bool do_color(void);
125 
126 int
127 main(int argc, char **argv)
128 {
129 	const char *errstr = NULL;
130 	char *ep, **oargv;
131 	long  l;
132 	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
133 
134 	oargv = argv;
135 	gotstdin = 0;
136 	dflags = 0;
137 	lastch = '\0';
138 	prevoptind = 1;
139 	newarg = 1;
140 	diff_context = 3;
141 	diff_format = D_UNSET;
142 #define	FORMAT_MISMATCHED(type)	\
143 	(diff_format != D_UNSET && diff_format != (type))
144 	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
145 		switch (ch) {
146 		case '0': case '1': case '2': case '3': case '4':
147 		case '5': case '6': case '7': case '8': case '9':
148 			if (newarg)
149 				usage();	/* disallow -[0-9]+ */
150 			else if (lastch == 'c' || lastch == 'u')
151 				diff_context = 0;
152 			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
153 				usage();
154 			diff_context = (diff_context * 10) + (ch - '0');
155 			break;
156 		case 'a':
157 			dflags |= D_FORCEASCII;
158 			break;
159 		case 'b':
160 			dflags |= D_FOLDBLANKS;
161 			break;
162 		case 'C':
163 		case 'c':
164 			if (FORMAT_MISMATCHED(D_CONTEXT))
165 				conflicting_format();
166 			cflag = true;
167 			diff_format = D_CONTEXT;
168 			if (optarg != NULL) {
169 				l = strtol(optarg, &ep, 10);
170 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
171 					usage();
172 				diff_context = (int)l;
173 			}
174 			break;
175 		case 'd':
176 			dflags |= D_MINIMAL;
177 			break;
178 		case 'D':
179 			if (FORMAT_MISMATCHED(D_IFDEF))
180 				conflicting_format();
181 			diff_format = D_IFDEF;
182 			ifdefname = optarg;
183 			break;
184 		case 'e':
185 			if (FORMAT_MISMATCHED(D_EDIT))
186 				conflicting_format();
187 			diff_format = D_EDIT;
188 			break;
189 		case 'f':
190 			if (FORMAT_MISMATCHED(D_REVERSE))
191 				conflicting_format();
192 			diff_format = D_REVERSE;
193 			break;
194 		case 'H':
195 			/* ignore but needed for compatibility with GNU diff */
196 			break;
197 		case 'h':
198 			/* silently ignore for backwards compatibility */
199 			break;
200 		case 'B':
201 			dflags |= D_SKIPBLANKLINES;
202 			break;
203 		case 'F':
204 			if (dflags & D_PROTOTYPE)
205 				conflicting_format();
206 			dflags |= D_MATCHLAST;
207 			most_recent_pat = xstrdup(optarg);
208 			break;
209 		case 'I':
210 			push_ignore_pats(optarg);
211 			break;
212 		case 'i':
213 			dflags |= D_IGNORECASE;
214 			break;
215 		case 'L':
216 			if (label[0] == NULL)
217 				label[0] = optarg;
218 			else if (label[1] == NULL)
219 				label[1] = optarg;
220 			else
221 				usage();
222 			break;
223 		case 'l':
224 			lflag = true;
225 			break;
226 		case 'N':
227 			Nflag = true;
228 			break;
229 		case 'n':
230 			if (FORMAT_MISMATCHED(D_NREVERSE))
231 				conflicting_format();
232 			diff_format = D_NREVERSE;
233 			break;
234 		case 'p':
235 			if (dflags & D_MATCHLAST)
236 				conflicting_format();
237 			dflags |= D_PROTOTYPE;
238 			break;
239 		case 'P':
240 			Pflag = true;
241 			break;
242 		case 'r':
243 			rflag = true;
244 			break;
245 		case 'q':
246 			if (FORMAT_MISMATCHED(D_BRIEF))
247 				conflicting_format();
248 			diff_format = D_BRIEF;
249 			break;
250 		case 'S':
251 			start = optarg;
252 			break;
253 		case 's':
254 			sflag = true;
255 			break;
256 		case 'T':
257 			Tflag = true;
258 			break;
259 		case 't':
260 			dflags |= D_EXPANDTABS;
261 			break;
262 		case 'U':
263 		case 'u':
264 			if (FORMAT_MISMATCHED(D_UNIFIED))
265 				conflicting_format();
266 			diff_format = D_UNIFIED;
267 			if (optarg != NULL) {
268 				l = strtol(optarg, &ep, 10);
269 				if (*ep != '\0' || l < 0 || l >= INT_MAX)
270 					usage();
271 				diff_context = (int)l;
272 			}
273 			break;
274 		case 'w':
275 			dflags |= D_IGNOREBLANKS;
276 			break;
277 		case 'W':
278 			width = (int) strtonum(optarg, 1, INT_MAX, &errstr);
279 			if (errstr) {
280 				warnx("Invalid argument for width");
281 				usage();
282 			}
283 			break;
284 		case 'X':
285 			read_excludes_file(optarg);
286 			break;
287 		case 'x':
288 			push_excludes(optarg);
289 			break;
290 		case 'y':
291 			if (FORMAT_MISMATCHED(D_SIDEBYSIDE))
292 				conflicting_format();
293 			diff_format = D_SIDEBYSIDE;
294 			break;
295 		case OPT_CHANGED_GROUP_FORMAT:
296 			if (FORMAT_MISMATCHED(D_GFORMAT))
297 				conflicting_format();
298 			diff_format = D_GFORMAT;
299 			group_format = optarg;
300 			break;
301 		case OPT_HELP:
302 			help = true;
303 			usage();
304 			break;
305 		case OPT_HORIZON_LINES:
306 			break; /* XXX TODO for compatibility with GNU diff3 */
307 		case OPT_IGN_FN_CASE:
308 			ignore_file_case = true;
309 			break;
310 		case OPT_NO_IGN_FN_CASE:
311 			ignore_file_case = false;
312 			break;
313 		case OPT_NORMAL:
314 			if (FORMAT_MISMATCHED(D_NORMAL))
315 				conflicting_format();
316 			diff_format = D_NORMAL;
317 			break;
318 		case OPT_TSIZE:
319 			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
320 			if (errstr) {
321 				warnx("Invalid argument for tabsize");
322 				usage();
323 			}
324 			break;
325 		case OPT_STRIPCR:
326 			dflags |= D_STRIPCR;
327 			break;
328 		case OPT_SUPPRESS_COMMON:
329 			suppress_common = 1;
330 			break;
331 		case OPT_COLOR:
332 			if (optarg == NULL || strncmp(optarg, "auto", 4) == 0)
333 				colorflag = COLORFLAG_AUTO;
334 			else if (strncmp(optarg, "always", 6) == 0)
335 				colorflag = COLORFLAG_ALWAYS;
336 			else if (strncmp(optarg, "never", 5) == 0)
337 				colorflag = COLORFLAG_NEVER;
338 			else
339 				errx(2, "unsupported --color value '%s' (must be always, auto, or never)",
340 					optarg);
341 			break;
342 		case OPT_NO_DEREFERENCE:
343 			rflag = true;
344 			noderef = true;
345 			break;
346 		case OPT_VERSION:
347 			printf("%s\n", diff_version);
348 			exit(0);
349 		default:
350 			usage();
351 			break;
352 		}
353 		lastch = ch;
354 		newarg = optind != prevoptind;
355 		prevoptind = optind;
356 	}
357 	if (diff_format == D_UNSET && (dflags & D_PROTOTYPE) != 0)
358 		diff_format = D_CONTEXT;
359 	if (diff_format == D_UNSET)
360 		diff_format = D_NORMAL;
361 	argc -= optind;
362 	argv += optind;
363 
364 	if (do_color()) {
365 		char *p;
366 		const char *env;
367 
368 		color = true;
369 		add_code = "32";
370 		del_code = "31";
371 		env = getenv("DIFFCOLORS");
372 		if (env != NULL && *env != '\0' && (p = strdup(env))) {
373 			add_code = p;
374 			strsep(&p, ":");
375 			if (p != NULL)
376 				del_code = p;
377 		}
378 	}
379 
380 #ifdef __OpenBSD__
381 	if (pledge("stdio rpath tmppath", NULL) == -1)
382 		err(2, "pledge");
383 #endif
384 
385 	/*
386 	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
387 	 * driver routine.  Both drivers use the contents of stb1 and stb2.
388 	 */
389 	if (argc != 2)
390 		usage();
391 	checked_regcomp(ignore_pats, &ignore_re);
392 	checked_regcomp(most_recent_pat, &most_recent_re);
393 	if (strcmp(argv[0], "-") == 0) {
394 		fstat(STDIN_FILENO, &stb1);
395 		gotstdin = 1;
396 	} else if (stat(argv[0], &stb1) != 0) {
397 		if (!Nflag || errno != ENOENT)
398 			err(2, "%s", argv[0]);
399 		dflags |= D_EMPTY1;
400 		memset(&stb1, 0, sizeof(struct stat));
401 	}
402 
403 	if (strcmp(argv[1], "-") == 0) {
404 		fstat(STDIN_FILENO, &stb2);
405 		gotstdin = 1;
406 	} else if (stat(argv[1], &stb2) != 0) {
407 		if (!Nflag || errno != ENOENT)
408 			err(2, "%s", argv[1]);
409 		dflags |= D_EMPTY2;
410 		memset(&stb2, 0, sizeof(stb2));
411 		stb2.st_mode = stb1.st_mode;
412 	}
413 
414 	if (dflags & D_EMPTY1 && dflags & D_EMPTY2){
415 		warn("%s", argv[0]);
416 		warn("%s", argv[1]);
417 		exit(2);
418 	}
419 
420 	if (stb1.st_mode == 0)
421 		stb1.st_mode = stb2.st_mode;
422 
423 	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
424 		errx(2, "can't compare - to a directory");
425 	set_argstr(oargv, argv);
426 	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
427 		if (diff_format == D_IFDEF)
428 			errx(2, "-D option not supported with directories");
429 		diffdir(argv[0], argv[1], dflags);
430 	} else {
431 		if (S_ISDIR(stb1.st_mode)) {
432 			argv[0] = splice(argv[0], argv[1]);
433 			if (stat(argv[0], &stb1) == -1)
434 				err(2, "%s", argv[0]);
435 		}
436 		if (S_ISDIR(stb2.st_mode)) {
437 			argv[1] = splice(argv[1], argv[0]);
438 			if (stat(argv[1], &stb2) == -1)
439 				err(2, "%s", argv[1]);
440 		}
441 		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
442 		    argv[1], "");
443 	}
444 	exit(status);
445 }
446 
447 static void
448 checked_regcomp(char const *pattern, regex_t *comp)
449 {
450 	char buf[BUFSIZ];
451 	int error;
452 
453 	if (pattern == NULL)
454 		return;
455 
456 	error = regcomp(comp, pattern, REG_NEWLINE | REG_EXTENDED);
457 	if (error != 0) {
458 		regerror(error, comp, buf, sizeof(buf));
459 		if (*pattern != '\0')
460 			errx(2, "%s: %s", pattern, buf);
461 		else
462 			errx(2, "%s", buf);
463 	}
464 }
465 
466 static void
467 set_argstr(char **av, char **ave)
468 {
469 	size_t argsize;
470 	char **ap;
471 
472 	argsize = 4 + *ave - *av + 1;
473 	diffargs = xmalloc(argsize);
474 	strlcpy(diffargs, "diff", argsize);
475 	for (ap = av + 1; ap < ave; ap++) {
476 		if (strcmp(*ap, "--") != 0) {
477 			strlcat(diffargs, " ", argsize);
478 			strlcat(diffargs, *ap, argsize);
479 		}
480 	}
481 }
482 
483 /*
484  * Read in an excludes file and push each line.
485  */
486 static void
487 read_excludes_file(char *file)
488 {
489 	FILE *fp;
490 	char *buf, *pattern;
491 	size_t len;
492 
493 	if (strcmp(file, "-") == 0)
494 		fp = stdin;
495 	else if ((fp = fopen(file, "r")) == NULL)
496 		err(2, "%s", file);
497 	while ((buf = fgetln(fp, &len)) != NULL) {
498 		if (buf[len - 1] == '\n')
499 			len--;
500 		if ((pattern = strndup(buf, len)) == NULL)
501 			err(2, "xstrndup");
502 		push_excludes(pattern);
503 	}
504 	if (strcmp(file, "-") != 0)
505 		fclose(fp);
506 }
507 
508 /*
509  * Push a pattern onto the excludes list.
510  */
511 static void
512 push_excludes(char *pattern)
513 {
514 	struct excludes *entry;
515 
516 	entry = xmalloc(sizeof(*entry));
517 	entry->pattern = pattern;
518 	entry->next = excludes_list;
519 	excludes_list = entry;
520 }
521 
522 static void
523 push_ignore_pats(char *pattern)
524 {
525 	size_t len;
526 
527 	if (ignore_pats == NULL)
528 		ignore_pats = xstrdup(pattern);
529 	else {
530 		/* old + "|" + new + NUL */
531 		len = strlen(ignore_pats) + strlen(pattern) + 2;
532 		ignore_pats = xreallocarray(ignore_pats, 1, len);
533 		strlcat(ignore_pats, "|", len);
534 		strlcat(ignore_pats, pattern, len);
535 	}
536 }
537 
538 void
539 print_status(int val, char *path1, char *path2, const char *entry)
540 {
541 	if (label[0] != NULL)
542 		path1 = label[0];
543 	if (label[1] != NULL)
544 		path2 = label[1];
545 
546 	switch (val) {
547 	case D_BINARY:
548 		printf("Binary files %s%s and %s%s differ\n",
549 		    path1, entry, path2, entry);
550 		break;
551 	case D_DIFFER:
552 		if (diff_format == D_BRIEF)
553 			printf("Files %s%s and %s%s differ\n",
554 			    path1, entry, path2, entry);
555 		break;
556 	case D_SAME:
557 		if (sflag)
558 			printf("Files %s%s and %s%s are identical\n",
559 			    path1, entry, path2, entry);
560 		break;
561 	case D_MISMATCH1:
562 		printf("File %s%s is a directory while file %s%s is a regular file\n",
563 		    path1, entry, path2, entry);
564 		break;
565 	case D_MISMATCH2:
566 		printf("File %s%s is a regular file while file %s%s is a directory\n",
567 		    path1, entry, path2, entry);
568 		break;
569 	case D_SKIPPED1:
570 		printf("File %s%s is not a regular file or directory and was skipped\n",
571 		    path1, entry);
572 		break;
573 	case D_SKIPPED2:
574 		printf("File %s%s is not a regular file or directory and was skipped\n",
575 		    path2, entry);
576 		break;
577 	case D_ERROR:
578 		break;
579 	}
580 }
581 
582 static void
583 usage(void)
584 {
585 	(void)fprintf(help ? stdout : stderr,
586 	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
587 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
588 	    "            [-I pattern] [-F pattern] [-L label] file1 file2\n"
589 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
590 	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
591 	    "            [-F pattern] -C number file1 file2\n"
592 	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
593 	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
594 	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
595 	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
596 	    "            [-F pattern] -U number file1 file2\n"
597 	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
598 	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
599 	    "            [-F pattern] [-S name] [-X file] [-x pattern] dir1 dir2\n"
600 	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
601 	    "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
602 	    "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
603 	    "            [--suppress-common-lines] [--tabsize] [--text] [--width]\n"
604 	    "            -y | --side-by-side file1 file2\n"
605 	    "       diff [--help] [--version]\n");
606 
607 	if (help)
608 		exit(0);
609 	else
610 		exit(2);
611 }
612 
613 static void
614 conflicting_format(void)
615 {
616 
617 	fprintf(stderr, "error: conflicting output format options.\n");
618 	usage();
619 }
620 
621 static bool
622 do_color(void)
623 {
624 	const char *p, *p2;
625 
626 	switch (colorflag) {
627 	case COLORFLAG_AUTO:
628 		p = getenv("CLICOLOR");
629 		p2 = getenv("COLORTERM");
630 		if ((p != NULL && *p != '\0') || (p2 != NULL && *p2 != '\0'))
631 			return isatty(STDOUT_FILENO);
632 		break;
633 	case COLORFLAG_ALWAYS:
634 		return (true);
635 	case COLORFLAG_NEVER:
636 		return (false);
637 	}
638 
639 	return (false);
640 }
641 
642 static char *
643 splice(char *dir, char *path)
644 {
645 	char *tail, *buf;
646 	size_t dirlen;
647 
648 	dirlen = strlen(dir);
649 	while (dirlen != 0 && dir[dirlen - 1] == '/')
650 	    dirlen--;
651 	if ((tail = strrchr(path, '/')) == NULL)
652 		tail = path;
653 	else
654 		tail++;
655 	xasprintf(&buf, "%.*s/%s", (int)dirlen, dir, tail);
656 	return (buf);
657 }
658