xref: /freebsd/usr.bin/diff/diff.c (revision 96b917bfcf2c558340f8f6e620e64efededa1daf)
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  __FBSDID("$FreeBSD$");
25  
26  #include <sys/stat.h>
27  
28  #include <ctype.h>
29  #include <err.h>
30  #include <errno.h>
31  #include <getopt.h>
32  #include <stdlib.h>
33  #include <stdio.h>
34  #include <string.h>
35  #include <unistd.h>
36  #include <limits.h>
37  
38  #include "diff.h"
39  #include "xmalloc.h"
40  
41  static const char diff_version[] = "FreeBSD diff 20220309";
42  bool	 lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag;
43  bool	 ignore_file_case, suppress_common, color, noderef;
44  static bool help = false;
45  int	 diff_format, diff_context, status;
46  int	 tabsize = 8, width = 130;
47  static int	colorflag = COLORFLAG_NEVER;
48  char	*start, *ifdefname, *diffargs, *label[2];
49  char	*ignore_pats, *most_recent_pat;
50  char	*group_format = NULL;
51  const char	*add_code, *del_code;
52  struct stat stb1, stb2;
53  struct excludes *excludes_list;
54  regex_t	 ignore_re, most_recent_re;
55  
56  #define	OPTIONS	"0123456789aBbC:cdD:efF:HhI:iL:lnNPpqrS:sTtU:uwW:X:x:y"
57  enum {
58  	OPT_TSIZE = CHAR_MAX + 1,
59  	OPT_STRIPCR,
60  	OPT_IGN_FN_CASE,
61  	OPT_NO_IGN_FN_CASE,
62  	OPT_NORMAL,
63  	OPT_HELP,
64  	OPT_HORIZON_LINES,
65  	OPT_CHANGED_GROUP_FORMAT,
66  	OPT_SUPPRESS_COMMON,
67  	OPT_COLOR,
68  	OPT_NO_DEREFERENCE,
69  	OPT_VERSION,
70  };
71  
72  static struct option longopts[] = {
73  	{ "text",			no_argument,		0,	'a' },
74  	{ "ignore-space-change",	no_argument,		0,	'b' },
75  	{ "context",			optional_argument,	0,	'C' },
76  	{ "ifdef",			required_argument,	0,	'D' },
77  	{ "minimal",			no_argument,		0,	'd' },
78  	{ "ed",				no_argument,		0,	'e' },
79  	{ "forward-ed",			no_argument,		0,	'f' },
80  	{ "show-function-line",		required_argument,	0,	'F' },
81  	{ "speed-large-files",		no_argument,		NULL,	'H' },
82  	{ "ignore-blank-lines",		no_argument,		0,	'B' },
83  	{ "ignore-matching-lines",	required_argument,	0,	'I' },
84  	{ "ignore-case",		no_argument,		0,	'i' },
85  	{ "paginate",			no_argument,		NULL,	'l' },
86  	{ "label",			required_argument,	0,	'L' },
87  	{ "new-file",			no_argument,		0,	'N' },
88  	{ "rcs",			no_argument,		0,	'n' },
89  	{ "unidirectional-new-file",	no_argument,		0,	'P' },
90  	{ "show-c-function",		no_argument,		0,	'p' },
91  	{ "brief",			no_argument,		0,	'q' },
92  	{ "recursive",			no_argument,		0,	'r' },
93  	{ "report-identical-files",	no_argument,		0,	's' },
94  	{ "starting-file",		required_argument,	0,	'S' },
95  	{ "expand-tabs",		no_argument,		0,	't' },
96  	{ "initial-tab",		no_argument,		0,	'T' },
97  	{ "unified",			optional_argument,	0,	'U' },
98  	{ "ignore-all-space",		no_argument,		0,	'w' },
99  	{ "width",			required_argument,	0,	'W' },
100  	{ "exclude",			required_argument,	0,	'x' },
101  	{ "exclude-from",		required_argument,	0,	'X' },
102  	{ "side-by-side",		no_argument,		NULL,	'y' },
103  	{ "ignore-file-name-case",	no_argument,		NULL,	OPT_IGN_FN_CASE },
104  	{ "help",			no_argument,		NULL,	OPT_HELP},
105  	{ "horizon-lines",		required_argument,	NULL,	OPT_HORIZON_LINES },
106  	{ "no-dereference",		no_argument,		NULL,	OPT_NO_DEREFERENCE},
107  	{ "no-ignore-file-name-case",	no_argument,		NULL,	OPT_NO_IGN_FN_CASE },
108  	{ "normal",			no_argument,		NULL,	OPT_NORMAL },
109  	{ "strip-trailing-cr",		no_argument,		NULL,	OPT_STRIPCR },
110  	{ "tabsize",			required_argument,	NULL,	OPT_TSIZE },
111  	{ "changed-group-format",	required_argument,	NULL,	OPT_CHANGED_GROUP_FORMAT},
112  	{ "suppress-common-lines",	no_argument,		NULL,	OPT_SUPPRESS_COMMON },
113  	{ "color",			optional_argument,	NULL,	OPT_COLOR },
114  	{ "version",			no_argument,		NULL,	OPT_VERSION},
115  	{ NULL,				0,			0,	'\0'}
116  };
117  
118  static void checked_regcomp(char const *, regex_t *);
119  static void usage(void) __dead2;
120  static void conflicting_format(void) __dead2;
121  static void push_excludes(char *);
122  static void push_ignore_pats(char *);
123  static void read_excludes_file(char *file);
124  static void set_argstr(char **, char **);
125  static char *splice(char *, char *);
126  static bool do_color(void);
127  
128  int
129  main(int argc, char **argv)
130  {
131  	const char *errstr = NULL;
132  	char *ep, **oargv;
133  	long  l;
134  	int   ch, dflags, lastch, gotstdin, prevoptind, newarg;
135  
136  	oargv = argv;
137  	gotstdin = 0;
138  	dflags = 0;
139  	lastch = '\0';
140  	prevoptind = 1;
141  	newarg = 1;
142  	diff_context = 3;
143  	diff_format = D_UNSET;
144  #define	FORMAT_MISMATCHED(type)	\
145  	(diff_format != D_UNSET && diff_format != (type))
146  	while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) {
147  		switch (ch) {
148  		case '0': case '1': case '2': case '3': case '4':
149  		case '5': case '6': case '7': case '8': case '9':
150  			if (newarg)
151  				usage();	/* disallow -[0-9]+ */
152  			else if (lastch == 'c' || lastch == 'u')
153  				diff_context = 0;
154  			else if (!isdigit(lastch) || diff_context > INT_MAX / 10)
155  				usage();
156  			diff_context = (diff_context * 10) + (ch - '0');
157  			break;
158  		case 'a':
159  			dflags |= D_FORCEASCII;
160  			break;
161  		case 'b':
162  			dflags |= D_FOLDBLANKS;
163  			break;
164  		case 'C':
165  		case 'c':
166  			if (FORMAT_MISMATCHED(D_CONTEXT))
167  				conflicting_format();
168  			cflag = true;
169  			diff_format = D_CONTEXT;
170  			if (optarg != NULL) {
171  				l = strtol(optarg, &ep, 10);
172  				if (*ep != '\0' || l < 0 || l >= INT_MAX)
173  					usage();
174  				diff_context = (int)l;
175  			}
176  			break;
177  		case 'd':
178  			dflags |= D_MINIMAL;
179  			break;
180  		case 'D':
181  			if (FORMAT_MISMATCHED(D_IFDEF))
182  				conflicting_format();
183  			diff_format = D_IFDEF;
184  			ifdefname = optarg;
185  			break;
186  		case 'e':
187  			if (FORMAT_MISMATCHED(D_EDIT))
188  				conflicting_format();
189  			diff_format = D_EDIT;
190  			break;
191  		case 'f':
192  			if (FORMAT_MISMATCHED(D_REVERSE))
193  				conflicting_format();
194  			diff_format = D_REVERSE;
195  			break;
196  		case 'H':
197  			/* ignore but needed for compatibility with GNU diff */
198  			break;
199  		case 'h':
200  			/* silently ignore for backwards compatibility */
201  			break;
202  		case 'B':
203  			dflags |= D_SKIPBLANKLINES;
204  			break;
205  		case 'F':
206  			if (dflags & D_PROTOTYPE)
207  				conflicting_format();
208  			dflags |= D_MATCHLAST;
209  			most_recent_pat = xstrdup(optarg);
210  			break;
211  		case 'I':
212  			push_ignore_pats(optarg);
213  			break;
214  		case 'i':
215  			dflags |= D_IGNORECASE;
216  			break;
217  		case 'L':
218  			if (label[0] == NULL)
219  				label[0] = optarg;
220  			else if (label[1] == NULL)
221  				label[1] = optarg;
222  			else
223  				usage();
224  			break;
225  		case 'l':
226  			lflag = true;
227  			break;
228  		case 'N':
229  			Nflag = true;
230  			break;
231  		case 'n':
232  			if (FORMAT_MISMATCHED(D_NREVERSE))
233  				conflicting_format();
234  			diff_format = D_NREVERSE;
235  			break;
236  		case 'p':
237  			if (dflags & D_MATCHLAST)
238  				conflicting_format();
239  			dflags |= D_PROTOTYPE;
240  			break;
241  		case 'P':
242  			Pflag = true;
243  			break;
244  		case 'r':
245  			rflag = true;
246  			break;
247  		case 'q':
248  			if (FORMAT_MISMATCHED(D_BRIEF))
249  				conflicting_format();
250  			diff_format = D_BRIEF;
251  			break;
252  		case 'S':
253  			start = optarg;
254  			break;
255  		case 's':
256  			sflag = true;
257  			break;
258  		case 'T':
259  			Tflag = true;
260  			break;
261  		case 't':
262  			dflags |= D_EXPANDTABS;
263  			break;
264  		case 'U':
265  		case 'u':
266  			if (FORMAT_MISMATCHED(D_UNIFIED))
267  				conflicting_format();
268  			diff_format = D_UNIFIED;
269  			if (optarg != NULL) {
270  				l = strtol(optarg, &ep, 10);
271  				if (*ep != '\0' || l < 0 || l >= INT_MAX)
272  					usage();
273  				diff_context = (int)l;
274  			}
275  			break;
276  		case 'w':
277  			dflags |= D_IGNOREBLANKS;
278  			break;
279  		case 'W':
280  			width = (int) strtonum(optarg, 1, INT_MAX, &errstr);
281  			if (errstr) {
282  				warnx("Invalid argument for width");
283  				usage();
284  			}
285  			break;
286  		case 'X':
287  			read_excludes_file(optarg);
288  			break;
289  		case 'x':
290  			push_excludes(optarg);
291  			break;
292  		case 'y':
293  			if (FORMAT_MISMATCHED(D_SIDEBYSIDE))
294  				conflicting_format();
295  			diff_format = D_SIDEBYSIDE;
296  			break;
297  		case OPT_CHANGED_GROUP_FORMAT:
298  			if (FORMAT_MISMATCHED(D_GFORMAT))
299  				conflicting_format();
300  			diff_format = D_GFORMAT;
301  			group_format = optarg;
302  			break;
303  		case OPT_HELP:
304  			help = true;
305  			usage();
306  			break;
307  		case OPT_HORIZON_LINES:
308  			break; /* XXX TODO for compatibility with GNU diff3 */
309  		case OPT_IGN_FN_CASE:
310  			ignore_file_case = true;
311  			break;
312  		case OPT_NO_IGN_FN_CASE:
313  			ignore_file_case = false;
314  			break;
315  		case OPT_NORMAL:
316  			if (FORMAT_MISMATCHED(D_NORMAL))
317  				conflicting_format();
318  			diff_format = D_NORMAL;
319  			break;
320  		case OPT_TSIZE:
321  			tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr);
322  			if (errstr) {
323  				warnx("Invalid argument for tabsize");
324  				usage();
325  			}
326  			break;
327  		case OPT_STRIPCR:
328  			dflags |= D_STRIPCR;
329  			break;
330  		case OPT_SUPPRESS_COMMON:
331  			suppress_common = 1;
332  			break;
333  		case OPT_COLOR:
334  			if (optarg == NULL || strncmp(optarg, "auto", 4) == 0)
335  				colorflag = COLORFLAG_AUTO;
336  			else if (strncmp(optarg, "always", 6) == 0)
337  				colorflag = COLORFLAG_ALWAYS;
338  			else if (strncmp(optarg, "never", 5) == 0)
339  				colorflag = COLORFLAG_NEVER;
340  			else
341  				errx(2, "unsupported --color value '%s' (must be always, auto, or never)",
342  					optarg);
343  			break;
344  		case OPT_NO_DEREFERENCE:
345  			rflag = true;
346  			noderef = true;
347  			break;
348  		case OPT_VERSION:
349  			printf("%s\n", diff_version);
350  			exit(0);
351  		default:
352  			usage();
353  			break;
354  		}
355  		lastch = ch;
356  		newarg = optind != prevoptind;
357  		prevoptind = optind;
358  	}
359  	if (diff_format == D_UNSET && (dflags & D_PROTOTYPE) != 0)
360  		diff_format = D_CONTEXT;
361  	if (diff_format == D_UNSET)
362  		diff_format = D_NORMAL;
363  	argc -= optind;
364  	argv += optind;
365  
366  	if (do_color()) {
367  		char *p;
368  		const char *env;
369  
370  		color = true;
371  		add_code = "32";
372  		del_code = "31";
373  		env = getenv("DIFFCOLORS");
374  		if (env != NULL && *env != '\0' && (p = strdup(env))) {
375  			add_code = p;
376  			strsep(&p, ":");
377  			if (p != NULL)
378  				del_code = p;
379  		}
380  	}
381  
382  #ifdef __OpenBSD__
383  	if (pledge("stdio rpath tmppath", NULL) == -1)
384  		err(2, "pledge");
385  #endif
386  
387  	/*
388  	 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
389  	 * driver routine.  Both drivers use the contents of stb1 and stb2.
390  	 */
391  	if (argc != 2)
392  		usage();
393  	checked_regcomp(ignore_pats, &ignore_re);
394  	checked_regcomp(most_recent_pat, &most_recent_re);
395  	if (strcmp(argv[0], "-") == 0) {
396  		fstat(STDIN_FILENO, &stb1);
397  		gotstdin = 1;
398  	} else if (stat(argv[0], &stb1) != 0) {
399  		if (!Nflag || errno != ENOENT)
400  			err(2, "%s", argv[0]);
401  		dflags |= D_EMPTY1;
402  		memset(&stb1, 0, sizeof(struct stat));
403  	}
404  
405  	if (strcmp(argv[1], "-") == 0) {
406  		fstat(STDIN_FILENO, &stb2);
407  		gotstdin = 1;
408  	} else if (stat(argv[1], &stb2) != 0) {
409  		if (!Nflag || errno != ENOENT)
410  			err(2, "%s", argv[1]);
411  		dflags |= D_EMPTY2;
412  		memset(&stb2, 0, sizeof(stb2));
413  		stb2.st_mode = stb1.st_mode;
414  	}
415  
416  	if (dflags & D_EMPTY1 && dflags & D_EMPTY2){
417  		warn("%s", argv[0]);
418  		warn("%s", argv[1]);
419  		exit(2);
420  	}
421  
422  	if (stb1.st_mode == 0)
423  		stb1.st_mode = stb2.st_mode;
424  
425  	if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
426  		errx(2, "can't compare - to a directory");
427  	set_argstr(oargv, argv);
428  	if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
429  		if (diff_format == D_IFDEF)
430  			errx(2, "-D option not supported with directories");
431  		diffdir(argv[0], argv[1], dflags);
432  	} else {
433  		if (S_ISDIR(stb1.st_mode)) {
434  			argv[0] = splice(argv[0], argv[1]);
435  			if (stat(argv[0], &stb1) == -1)
436  				err(2, "%s", argv[0]);
437  		}
438  		if (S_ISDIR(stb2.st_mode)) {
439  			argv[1] = splice(argv[1], argv[0]);
440  			if (stat(argv[1], &stb2) == -1)
441  				err(2, "%s", argv[1]);
442  		}
443  		print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0],
444  		    argv[1], "");
445  	}
446  	exit(status);
447  }
448  
449  static void
450  checked_regcomp(char const *pattern, regex_t *comp)
451  {
452  	char buf[BUFSIZ];
453  	int error;
454  
455  	if (pattern == NULL)
456  		return;
457  
458  	error = regcomp(comp, pattern, REG_NEWLINE | REG_EXTENDED);
459  	if (error != 0) {
460  		regerror(error, comp, buf, sizeof(buf));
461  		if (*pattern != '\0')
462  			errx(2, "%s: %s", pattern, buf);
463  		else
464  			errx(2, "%s", buf);
465  	}
466  }
467  
468  static void
469  set_argstr(char **av, char **ave)
470  {
471  	size_t argsize;
472  	char **ap;
473  
474  	argsize = 4 + *ave - *av + 1;
475  	diffargs = xmalloc(argsize);
476  	strlcpy(diffargs, "diff", argsize);
477  	for (ap = av + 1; ap < ave; ap++) {
478  		if (strcmp(*ap, "--") != 0) {
479  			strlcat(diffargs, " ", argsize);
480  			strlcat(diffargs, *ap, argsize);
481  		}
482  	}
483  }
484  
485  /*
486   * Read in an excludes file and push each line.
487   */
488  static void
489  read_excludes_file(char *file)
490  {
491  	FILE *fp;
492  	char *buf, *pattern;
493  	size_t len;
494  
495  	if (strcmp(file, "-") == 0)
496  		fp = stdin;
497  	else if ((fp = fopen(file, "r")) == NULL)
498  		err(2, "%s", file);
499  	while ((buf = fgetln(fp, &len)) != NULL) {
500  		if (buf[len - 1] == '\n')
501  			len--;
502  		if ((pattern = strndup(buf, len)) == NULL)
503  			err(2, "xstrndup");
504  		push_excludes(pattern);
505  	}
506  	if (strcmp(file, "-") != 0)
507  		fclose(fp);
508  }
509  
510  /*
511   * Push a pattern onto the excludes list.
512   */
513  static void
514  push_excludes(char *pattern)
515  {
516  	struct excludes *entry;
517  
518  	entry = xmalloc(sizeof(*entry));
519  	entry->pattern = pattern;
520  	entry->next = excludes_list;
521  	excludes_list = entry;
522  }
523  
524  static void
525  push_ignore_pats(char *pattern)
526  {
527  	size_t len;
528  
529  	if (ignore_pats == NULL)
530  		ignore_pats = xstrdup(pattern);
531  	else {
532  		/* old + "|" + new + NUL */
533  		len = strlen(ignore_pats) + strlen(pattern) + 2;
534  		ignore_pats = xreallocarray(ignore_pats, 1, len);
535  		strlcat(ignore_pats, "|", len);
536  		strlcat(ignore_pats, pattern, len);
537  	}
538  }
539  
540  void
541  print_status(int val, char *path1, char *path2, const char *entry)
542  {
543  	if (label[0] != NULL)
544  		path1 = label[0];
545  	if (label[1] != NULL)
546  		path2 = label[1];
547  
548  	switch (val) {
549  	case D_BINARY:
550  		printf("Binary files %s%s and %s%s differ\n",
551  		    path1, entry, path2, entry);
552  		break;
553  	case D_DIFFER:
554  		if (diff_format == D_BRIEF)
555  			printf("Files %s%s and %s%s differ\n",
556  			    path1, entry, path2, entry);
557  		break;
558  	case D_SAME:
559  		if (sflag)
560  			printf("Files %s%s and %s%s are identical\n",
561  			    path1, entry, path2, entry);
562  		break;
563  	case D_MISMATCH1:
564  		printf("File %s%s is a directory while file %s%s is a regular file\n",
565  		    path1, entry, path2, entry);
566  		break;
567  	case D_MISMATCH2:
568  		printf("File %s%s is a regular file while file %s%s is a directory\n",
569  		    path1, entry, path2, entry);
570  		break;
571  	case D_SKIPPED1:
572  		printf("File %s%s is not a regular file or directory and was skipped\n",
573  		    path1, entry);
574  		break;
575  	case D_SKIPPED2:
576  		printf("File %s%s is not a regular file or directory and was skipped\n",
577  		    path2, entry);
578  		break;
579  	case D_ERROR:
580  		break;
581  	}
582  }
583  
584  static void
585  usage(void)
586  {
587  	(void)fprintf(help ? stdout : stderr,
588  	    "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
589  	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
590  	    "            [-I pattern] [-F pattern] [-L label] file1 file2\n"
591  	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
592  	    "            [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n"
593  	    "            [-F pattern] -C number file1 file2\n"
594  	    "       diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n"
595  	    "            [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n"
596  	    "       diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n"
597  	    "            [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n"
598  	    "            [-F pattern] -U number file1 file2\n"
599  	    "       diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n"
600  	    "            [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n"
601  	    "            [-F pattern] [-S name] [-X file] [-x pattern] dir1 dir2\n"
602  	    "       diff [-aBbditwW] [--expand-tabs] [--ignore-all-blanks]\n"
603  	    "            [--ignore-blank-lines] [--ignore-case] [--minimal]\n"
604  	    "            [--no-ignore-file-name-case] [--strip-trailing-cr]\n"
605  	    "            [--suppress-common-lines] [--tabsize] [--text] [--width]\n"
606  	    "            -y | --side-by-side file1 file2\n"
607  	    "       diff [--help] [--version]\n");
608  
609  	if (help)
610  		exit(0);
611  	else
612  		exit(2);
613  }
614  
615  static void
616  conflicting_format(void)
617  {
618  
619  	fprintf(stderr, "error: conflicting output format options.\n");
620  	usage();
621  }
622  
623  static bool
624  do_color(void)
625  {
626  	const char *p, *p2;
627  
628  	switch (colorflag) {
629  	case COLORFLAG_AUTO:
630  		p = getenv("CLICOLOR");
631  		p2 = getenv("COLORTERM");
632  		if ((p != NULL && *p != '\0') || (p2 != NULL && *p2 != '\0'))
633  			return isatty(STDOUT_FILENO);
634  		break;
635  	case COLORFLAG_ALWAYS:
636  		return (true);
637  	case COLORFLAG_NEVER:
638  		return (false);
639  	}
640  
641  	return (false);
642  }
643  
644  static char *
645  splice(char *dir, char *path)
646  {
647  	char *tail, *buf;
648  	size_t dirlen;
649  
650  	dirlen = strlen(dir);
651  	while (dirlen != 0 && dir[dirlen - 1] == '/')
652  	    dirlen--;
653  	if ((tail = strrchr(path, '/')) == NULL)
654  		tail = path;
655  	else
656  		tail++;
657  	xasprintf(&buf, "%.*s/%s", (int)dirlen, dir, tail);
658  	return (buf);
659  }
660