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/stat.h> 24 25 #include <ctype.h> 26 #include <err.h> 27 #include <errno.h> 28 #include <getopt.h> 29 #include <limits.h> 30 #include <stdio.h> 31 #include <stdlib.h> 32 #include <string.h> 33 #include <unistd.h> 34 35 #include "diff.h" 36 #include "xmalloc.h" 37 38 static const char diff_version[] = "FreeBSD diff 20260206"; 39 bool lflag, Nflag, Pflag, rflag, sflag, Tflag, cflag; 40 bool ignore_file_case, suppress_common, color, noderef; 41 static bool help = false; 42 int diff_format, diff_context, diff_algorithm, status; 43 bool diff_algorithm_set; 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 static struct algorithm { 55 const char *name; 56 int id; 57 } algorithms[] = { 58 {"stone", D_DIFFSTONE}, 59 {"myers", D_DIFFMYERS}, 60 {"patience", D_DIFFPATIENCE}, 61 {NULL, D_DIFFNONE} 62 }; 63 64 #define OPTIONS "0123456789A:aBbC:cdD:efF:HhI:iL:lnNPpqrS:sTtU:uwW:X:x:y" 65 enum { 66 OPT_TSIZE = CHAR_MAX + 1, 67 OPT_STRIPCR, 68 OPT_IGN_FN_CASE, 69 OPT_NO_IGN_FN_CASE, 70 OPT_NORMAL, 71 OPT_HELP, 72 OPT_HORIZON_LINES, 73 OPT_CHANGED_GROUP_FORMAT, 74 OPT_SUPPRESS_COMMON, 75 OPT_COLOR, 76 OPT_NO_DEREFERENCE, 77 OPT_VERSION, 78 }; 79 80 static struct option longopts[] = { 81 { "algorithm", required_argument, 0, 'A' }, 82 { "text", no_argument, 0, 'a' }, 83 { "ignore-space-change", no_argument, 0, 'b' }, 84 { "context", optional_argument, 0, 'C' }, 85 { "ifdef", required_argument, 0, 'D' }, 86 { "minimal", no_argument, 0, 'd' }, 87 { "ed", no_argument, 0, 'e' }, 88 { "forward-ed", no_argument, 0, 'f' }, 89 { "show-function-line", required_argument, 0, 'F' }, 90 { "speed-large-files", no_argument, NULL, 'H' }, 91 { "ignore-blank-lines", no_argument, 0, 'B' }, 92 { "ignore-matching-lines", required_argument, 0, 'I' }, 93 { "ignore-case", no_argument, 0, 'i' }, 94 { "paginate", no_argument, NULL, 'l' }, 95 { "label", required_argument, 0, 'L' }, 96 { "new-file", no_argument, 0, 'N' }, 97 { "rcs", no_argument, 0, 'n' }, 98 { "unidirectional-new-file", no_argument, 0, 'P' }, 99 { "show-c-function", no_argument, 0, 'p' }, 100 { "brief", no_argument, 0, 'q' }, 101 { "recursive", no_argument, 0, 'r' }, 102 { "report-identical-files", no_argument, 0, 's' }, 103 { "starting-file", required_argument, 0, 'S' }, 104 { "expand-tabs", no_argument, 0, 't' }, 105 { "initial-tab", no_argument, 0, 'T' }, 106 { "unified", optional_argument, 0, 'U' }, 107 { "ignore-all-space", no_argument, 0, 'w' }, 108 { "width", required_argument, 0, 'W' }, 109 { "exclude", required_argument, 0, 'x' }, 110 { "exclude-from", required_argument, 0, 'X' }, 111 { "side-by-side", no_argument, NULL, 'y' }, 112 { "ignore-file-name-case", no_argument, NULL, OPT_IGN_FN_CASE }, 113 { "help", no_argument, NULL, OPT_HELP}, 114 { "horizon-lines", required_argument, NULL, OPT_HORIZON_LINES }, 115 { "no-dereference", no_argument, NULL, OPT_NO_DEREFERENCE}, 116 { "no-ignore-file-name-case", no_argument, NULL, OPT_NO_IGN_FN_CASE }, 117 { "normal", no_argument, NULL, OPT_NORMAL }, 118 { "strip-trailing-cr", no_argument, NULL, OPT_STRIPCR }, 119 { "tabsize", required_argument, NULL, OPT_TSIZE }, 120 { "changed-group-format", required_argument, NULL, OPT_CHANGED_GROUP_FORMAT}, 121 { "suppress-common-lines", no_argument, NULL, OPT_SUPPRESS_COMMON }, 122 { "color", optional_argument, NULL, OPT_COLOR }, 123 { "version", no_argument, NULL, OPT_VERSION}, 124 { NULL, 0, 0, '\0'} 125 }; 126 127 static void checked_regcomp(char const *, regex_t *); 128 static void usage(void) __dead2; 129 static void conflicting_format(void) __dead2; 130 static void push_excludes(char *); 131 static void push_ignore_pats(char *); 132 static void read_excludes_file(char *file); 133 static void set_argstr(char **, char **); 134 static char *splice(char *, char *); 135 static bool do_color(void); 136 137 int 138 main(int argc, char **argv) 139 { 140 const char *errstr; 141 char **oargv; 142 int ch, dflags, lastch, gotstdin, prevoptind, newarg; 143 144 oargv = argv; 145 gotstdin = 0; 146 dflags = 0; 147 lastch = '\0'; 148 prevoptind = 1; 149 newarg = 1; 150 diff_context = 3; 151 diff_format = D_UNSET; 152 diff_algorithm = D_DIFFMYERS; 153 diff_algorithm_set = false; 154 #define FORMAT_MISMATCHED(type) \ 155 (diff_format != D_UNSET && diff_format != (type)) 156 while ((ch = getopt_long(argc, argv, OPTIONS, longopts, NULL)) != -1) { 157 switch (ch) { 158 case '0': case '1': case '2': case '3': case '4': 159 case '5': case '6': case '7': case '8': case '9': 160 if (newarg) 161 usage(); /* disallow -[0-9]+ */ 162 else if (lastch == 'c' || lastch == 'u') 163 diff_context = 0; 164 else if (!isdigit(lastch) || diff_context > INT_MAX / 10) 165 usage(); 166 diff_context = (diff_context * 10) + (ch - '0'); 167 break; 168 case 'A': 169 diff_algorithm = D_DIFFNONE; 170 for (struct algorithm *a = algorithms; a->name;a++) { 171 if(strcasecmp(optarg, a->name) == 0) { 172 diff_algorithm = a->id; 173 diff_algorithm_set = true; 174 break; 175 } 176 } 177 178 if (diff_algorithm == D_DIFFNONE) { 179 warnx("unknown algorithm: %s", optarg); 180 usage(); 181 } 182 break; 183 case 'a': 184 dflags |= D_FORCEASCII; 185 break; 186 case 'b': 187 dflags |= D_FOLDBLANKS; 188 break; 189 case 'C': 190 case 'c': 191 if (FORMAT_MISMATCHED(D_CONTEXT)) 192 conflicting_format(); 193 cflag = true; 194 diff_format = D_CONTEXT; 195 if (optarg != NULL) { 196 diff_context = (int) strtonum(optarg, 197 1, INT_MAX, &errstr); 198 if (errstr != NULL) { 199 warnx("context size is %s: %s", 200 errstr, optarg); 201 usage(); 202 } 203 } 204 break; 205 case 'd': 206 dflags |= D_MINIMAL; 207 break; 208 case 'D': 209 if (FORMAT_MISMATCHED(D_IFDEF)) 210 conflicting_format(); 211 diff_format = D_IFDEF; 212 ifdefname = optarg; 213 break; 214 case 'e': 215 if (FORMAT_MISMATCHED(D_EDIT)) 216 conflicting_format(); 217 diff_format = D_EDIT; 218 break; 219 case 'f': 220 if (FORMAT_MISMATCHED(D_REVERSE)) 221 conflicting_format(); 222 diff_format = D_REVERSE; 223 break; 224 case 'H': 225 /* ignore but needed for compatibility with GNU diff */ 226 break; 227 case 'h': 228 /* silently ignore for backwards compatibility */ 229 break; 230 case 'B': 231 dflags |= D_SKIPBLANKLINES; 232 break; 233 case 'F': 234 if (dflags & D_PROTOTYPE) 235 conflicting_format(); 236 dflags |= D_MATCHLAST; 237 most_recent_pat = xstrdup(optarg); 238 break; 239 case 'I': 240 push_ignore_pats(optarg); 241 break; 242 case 'i': 243 dflags |= D_IGNORECASE; 244 break; 245 case 'L': 246 if (label[0] == NULL) 247 label[0] = optarg; 248 else if (label[1] == NULL) 249 label[1] = optarg; 250 else 251 usage(); 252 break; 253 case 'l': 254 dflags |= D_PAGINATION; 255 lflag = true; 256 break; 257 case 'N': 258 Nflag = true; 259 break; 260 case 'n': 261 if (FORMAT_MISMATCHED(D_NREVERSE)) 262 conflicting_format(); 263 diff_format = D_NREVERSE; 264 break; 265 case 'p': 266 if (dflags & D_MATCHLAST) 267 conflicting_format(); 268 dflags |= D_PROTOTYPE; 269 break; 270 case 'P': 271 Pflag = true; 272 break; 273 case 'r': 274 rflag = true; 275 break; 276 case 'q': 277 if (FORMAT_MISMATCHED(D_BRIEF)) 278 conflicting_format(); 279 diff_format = D_BRIEF; 280 break; 281 case 'S': 282 start = optarg; 283 break; 284 case 's': 285 sflag = true; 286 break; 287 case 'T': 288 Tflag = true; 289 break; 290 case 't': 291 dflags |= D_EXPANDTABS; 292 break; 293 case 'U': 294 case 'u': 295 if (FORMAT_MISMATCHED(D_UNIFIED)) 296 conflicting_format(); 297 diff_format = D_UNIFIED; 298 if (optarg != NULL) { 299 diff_context = (int) strtonum(optarg, 300 0, INT_MAX, &errstr); 301 if (errstr != NULL) { 302 warnx("context size is %s: %s", 303 errstr, optarg); 304 usage(); 305 } 306 } 307 break; 308 case 'w': 309 dflags |= D_IGNOREBLANKS; 310 break; 311 case 'W': 312 width = (int) strtonum(optarg, 1, INT_MAX, &errstr); 313 if (errstr != NULL) { 314 warnx("width is %s: %s", errstr, optarg); 315 usage(); 316 } 317 break; 318 case 'X': 319 read_excludes_file(optarg); 320 break; 321 case 'x': 322 push_excludes(optarg); 323 break; 324 case 'y': 325 if (FORMAT_MISMATCHED(D_SIDEBYSIDE)) 326 conflicting_format(); 327 diff_format = D_SIDEBYSIDE; 328 break; 329 case OPT_CHANGED_GROUP_FORMAT: 330 if (FORMAT_MISMATCHED(D_GFORMAT)) 331 conflicting_format(); 332 diff_format = D_GFORMAT; 333 group_format = optarg; 334 break; 335 case OPT_HELP: 336 help = true; 337 usage(); 338 break; 339 case OPT_HORIZON_LINES: 340 break; /* XXX TODO for compatibility with GNU diff3 */ 341 case OPT_IGN_FN_CASE: 342 ignore_file_case = true; 343 break; 344 case OPT_NO_IGN_FN_CASE: 345 ignore_file_case = false; 346 break; 347 case OPT_NORMAL: 348 if (FORMAT_MISMATCHED(D_NORMAL)) 349 conflicting_format(); 350 diff_format = D_NORMAL; 351 break; 352 case OPT_TSIZE: 353 tabsize = (int) strtonum(optarg, 1, INT_MAX, &errstr); 354 if (errstr != NULL) { 355 warnx("tabsize is %s: %s", errstr, optarg); 356 usage(); 357 } 358 break; 359 case OPT_STRIPCR: 360 dflags |= D_STRIPCR; 361 break; 362 case OPT_SUPPRESS_COMMON: 363 suppress_common = 1; 364 break; 365 case OPT_COLOR: 366 if (optarg == NULL || strncmp(optarg, "auto", 4) == 0) 367 colorflag = COLORFLAG_AUTO; 368 else if (strncmp(optarg, "always", 6) == 0) 369 colorflag = COLORFLAG_ALWAYS; 370 else if (strncmp(optarg, "never", 5) == 0) 371 colorflag = COLORFLAG_NEVER; 372 else { 373 warnx("unsupported --color value " 374 "(must be always, auto, or never): " 375 "%s", optarg); 376 usage(); 377 } 378 break; 379 case OPT_NO_DEREFERENCE: 380 noderef = true; 381 break; 382 case OPT_VERSION: 383 printf("%s\n", diff_version); 384 exit(0); 385 default: 386 usage(); 387 break; 388 } 389 lastch = ch; 390 newarg = optind != prevoptind; 391 prevoptind = optind; 392 } 393 if (diff_format == D_UNSET && (dflags & D_PROTOTYPE) != 0) 394 diff_format = D_CONTEXT; 395 if (diff_format == D_UNSET) 396 diff_format = D_NORMAL; 397 argc -= optind; 398 argv += optind; 399 400 if (do_color()) { 401 char *p; 402 const char *env; 403 404 color = true; 405 add_code = "32"; 406 del_code = "31"; 407 env = getenv("DIFFCOLORS"); 408 if (env != NULL && *env != '\0' && (p = strdup(env))) { 409 add_code = p; 410 strsep(&p, ":"); 411 if (p != NULL) 412 del_code = p; 413 } 414 } 415 416 #ifdef __OpenBSD__ 417 if (pledge("stdio rpath tmppath", NULL) == -1) 418 err(2, "pledge"); 419 #endif 420 421 /* 422 * Do sanity checks, fill in stb1 and stb2 and call the appropriate 423 * driver routine. Both drivers use the contents of stb1 and stb2. 424 */ 425 if (argc != 2) 426 usage(); 427 checked_regcomp(ignore_pats, &ignore_re); 428 checked_regcomp(most_recent_pat, &most_recent_re); 429 if (strcmp(argv[0], "-") == 0) { 430 fstat(STDIN_FILENO, &stb1); 431 gotstdin = 1; 432 } else if (stat(argv[0], &stb1) != 0) { 433 if (!Nflag || errno != ENOENT) 434 err(2, "%s", argv[0]); 435 dflags |= D_EMPTY1; 436 memset(&stb1, 0, sizeof(struct stat)); 437 } 438 439 if (strcmp(argv[1], "-") == 0) { 440 fstat(STDIN_FILENO, &stb2); 441 gotstdin = 1; 442 } else if (stat(argv[1], &stb2) != 0) { 443 if (!Nflag || errno != ENOENT) 444 err(2, "%s", argv[1]); 445 dflags |= D_EMPTY2; 446 memset(&stb2, 0, sizeof(stb2)); 447 stb2.st_mode = stb1.st_mode; 448 } 449 450 if (dflags & D_EMPTY1 && dflags & D_EMPTY2){ 451 warn("%s", argv[0]); 452 warn("%s", argv[1]); 453 exit(2); 454 } 455 456 if (stb1.st_mode == 0) 457 stb1.st_mode = stb2.st_mode; 458 459 if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode))) 460 errx(2, "can't compare - to a directory"); 461 set_argstr(oargv, argv); 462 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) { 463 if (diff_format == D_IFDEF) 464 errx(2, "-D option not supported with directories"); 465 diffdir(argv[0], argv[1], dflags); 466 } else { 467 if (S_ISDIR(stb1.st_mode)) { 468 argv[0] = splice(argv[0], argv[1]); 469 if (stat(argv[0], &stb1) == -1) 470 err(2, "%s", argv[0]); 471 } 472 if (S_ISDIR(stb2.st_mode)) { 473 argv[1] = splice(argv[1], argv[0]); 474 if (stat(argv[1], &stb2) == -1) 475 err(2, "%s", argv[1]); 476 } 477 print_status(diffreg(argv[0], argv[1], dflags, 1), argv[0], 478 argv[1], ""); 479 } 480 if (fflush(stdout) != 0) 481 err(2, "stdout"); 482 exit(status); 483 } 484 485 static void 486 checked_regcomp(char const *pattern, regex_t *comp) 487 { 488 char buf[BUFSIZ]; 489 int error; 490 491 if (pattern == NULL) 492 return; 493 494 error = regcomp(comp, pattern, REG_NEWLINE | REG_EXTENDED); 495 if (error != 0) { 496 regerror(error, comp, buf, sizeof(buf)); 497 if (*pattern != '\0') 498 errx(2, "%s: %s", pattern, buf); 499 else 500 errx(2, "%s", buf); 501 } 502 } 503 504 static void 505 set_argstr(char **av, char **ave) 506 { 507 size_t argsize; 508 char **ap; 509 510 argsize = 4 + *ave - *av + 1; 511 diffargs = xmalloc(argsize); 512 strlcpy(diffargs, "diff", argsize); 513 for (ap = av + 1; ap < ave; ap++) { 514 if (strcmp(*ap, "--") != 0) { 515 strlcat(diffargs, " ", argsize); 516 strlcat(diffargs, *ap, argsize); 517 } 518 } 519 } 520 521 /* 522 * Read in an excludes file and push each line. 523 */ 524 static void 525 read_excludes_file(char *file) 526 { 527 FILE *fp; 528 char *pattern = NULL; 529 size_t blen = 0; 530 ssize_t len; 531 532 if (strcmp(file, "-") == 0) 533 fp = stdin; 534 else if ((fp = fopen(file, "r")) == NULL) 535 err(2, "%s", file); 536 while ((len = getline(&pattern, &blen, fp)) >= 0) { 537 if ((len > 0) && (pattern[len - 1] == '\n')) 538 pattern[len - 1] = '\0'; 539 push_excludes(pattern); 540 /* we allocate a new string per line */ 541 pattern = NULL; 542 blen = 0; 543 } 544 free(pattern); 545 if (strcmp(file, "-") != 0) 546 fclose(fp); 547 } 548 549 /* 550 * Push a pattern onto the excludes list. 551 */ 552 static void 553 push_excludes(char *pattern) 554 { 555 struct excludes *entry; 556 557 entry = xmalloc(sizeof(*entry)); 558 entry->pattern = pattern; 559 entry->next = excludes_list; 560 excludes_list = entry; 561 } 562 563 static void 564 push_ignore_pats(char *pattern) 565 { 566 size_t len; 567 568 if (ignore_pats == NULL) 569 ignore_pats = xstrdup(pattern); 570 else { 571 /* old + "|" + new + NUL */ 572 len = strlen(ignore_pats) + strlen(pattern) + 2; 573 ignore_pats = xreallocarray(ignore_pats, 1, len); 574 strlcat(ignore_pats, "|", len); 575 strlcat(ignore_pats, pattern, len); 576 } 577 } 578 579 void 580 print_status(int val, char *path1, char *path2, const char *entry) 581 { 582 if (label[0] != NULL) 583 path1 = label[0]; 584 if (label[1] != NULL) 585 path2 = label[1]; 586 587 switch (val) { 588 case D_BINARY: 589 printf("Binary files %s%s and %s%s differ\n", 590 path1, entry, path2, entry); 591 break; 592 case D_DIFFER: 593 if (diff_format == D_BRIEF) 594 printf("Files %s%s and %s%s differ\n", 595 path1, entry, path2, entry); 596 break; 597 case D_SAME: 598 if (sflag) 599 printf("Files %s%s and %s%s are identical\n", 600 path1, entry, path2, entry); 601 break; 602 case D_MISMATCH1: 603 printf("File %s%s is a directory while file %s%s is a regular file\n", 604 path1, entry, path2, entry); 605 break; 606 case D_MISMATCH2: 607 printf("File %s%s is a regular file while file %s%s is a directory\n", 608 path1, entry, path2, entry); 609 break; 610 case D_SKIPPED1: 611 printf("File %s%s is not a regular file or directory and was skipped\n", 612 path1, entry); 613 break; 614 case D_SKIPPED2: 615 printf("File %s%s is not a regular file or directory and was skipped\n", 616 path2, entry); 617 break; 618 case D_ERROR: 619 break; 620 } 621 } 622 623 static void 624 usage(void) 625 { 626 (void)fprintf(help ? stdout : stderr, 627 "usage: diff [-aBbdilpTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n" 628 " [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n" 629 " [-I pattern] [-F pattern] [-L label] file1 file2\n" 630 " diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n" 631 " [--no-ignore-case] [--normal] [--strip-trailing-cr] [--tabsize]\n" 632 " [-F pattern] -C number file1 file2\n" 633 " diff [-aBbdiltw] [-I pattern] [--ignore-case] [--no-ignore-case]\n" 634 " [--normal] [--strip-trailing-cr] [--tabsize] -D string file1 file2\n" 635 " diff [-aBbdilpTtw] [-I pattern] [-L label] [--ignore-case]\n" 636 " [--no-ignore-case] [--normal] [--tabsize] [--strip-trailing-cr]\n" 637 " [-F pattern] -U number file1 file2\n" 638 " diff [-aBbdilNPprsTtw] [-c | -e | -f | -n | -q | -u] [--ignore-case]\n" 639 " [--no-ignore-case] [--normal] [--tabsize] [-I pattern] [-L label]\n" 640 " [-F pattern] [-S name] [-X file] [-x pattern] dir1 dir2\n" 641 " diff [-aBbditwW] [--expand-tabs] [--ignore-all-space]\n" 642 " [--ignore-blank-lines] [--ignore-case] [--minimal]\n" 643 " [--no-ignore-file-name-case] [--strip-trailing-cr]\n" 644 " [--suppress-common-lines] [--tabsize] [--text] [--width]\n" 645 " -y | --side-by-side file1 file2\n" 646 " diff [--help] [--version]\n"); 647 648 if (help) 649 exit(0); 650 else 651 exit(2); 652 } 653 654 static void 655 conflicting_format(void) 656 { 657 658 fprintf(stderr, "error: conflicting output format options.\n"); 659 usage(); 660 } 661 662 static bool 663 do_color(void) 664 { 665 const char *p, *p2; 666 667 switch (colorflag) { 668 case COLORFLAG_AUTO: 669 p = getenv("CLICOLOR"); 670 p2 = getenv("COLORTERM"); 671 if ((p != NULL && *p != '\0') || (p2 != NULL && *p2 != '\0')) 672 return isatty(STDOUT_FILENO); 673 break; 674 case COLORFLAG_ALWAYS: 675 return (true); 676 case COLORFLAG_NEVER: 677 return (false); 678 } 679 680 return (false); 681 } 682 683 static char * 684 splice(char *dir, char *path) 685 { 686 char *tail, *buf; 687 size_t dirlen; 688 689 dirlen = strlen(dir); 690 while (dirlen != 0 && dir[dirlen - 1] == '/') 691 dirlen--; 692 if ((tail = strrchr(path, '/')) == NULL) 693 tail = path; 694 else 695 tail++; 696 xasprintf(&buf, "%.*s/%s", (int)dirlen, dir, tail); 697 return (buf); 698 } 699