2 * $OpenBSD: patch.c,v 1.45 2007/04/18 21:52:24 sobrado Exp $
3 * $DragonFly: src/usr.bin/patch/patch.c,v 1.10 2008/08/10 23:39:56 joerg Exp $
7 * patch - a program to apply diffs to original files
9 * Copyright 1986, Larry Wall
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following condition is met:
13 * 1. Redistributions of source code must retain the above copyright notice,
14 * this condition and the following disclaimer.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND ANY
17 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
23 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * -C option added in 1998, original code by Marc Espie, based on FreeBSD
32 #include <sys/types.h>
47 #include "backupfile.h"
48 #include "pathnames.h"
50 mode_t filemode = 0644;
52 char buf[MAXLINELEN]; /* general purpose buffer */
53 size_t buf_len = sizeof(buf);
55 bool using_plan_a = true; /* try to keep everything in memory */
56 bool out_of_mem = false; /* ran out of memory in plan a */
60 char *filearg[MAXFILEC];
61 bool ok_to_create_file = false;
63 char *origprae = NULL;
68 bool toutkeep = false;
69 bool trejkeep = false;
70 bool warn_on_invalid_line;
71 bool last_line_missing_eol;
81 bool noreverse = false;
82 bool skip_rest_of_patch = false;
84 bool canonicalize = false;
85 bool check_only = false;
87 char *revision = NULL; /* prerequisite revision, if any */
88 LINENUM input_lines = 0; /* how long is input file in lines */
89 int posix = 0; /* strict POSIX mode? */
91 static void reinitialize_almost_everything(void);
92 static void get_some_switches(void);
93 static LINENUM locate_hunk(LINENUM);
94 static void abort_context_hunk(void);
95 static void rej_line(int, LINENUM);
96 static void abort_hunk(void);
97 static void apply_hunk(LINENUM);
98 static void init_output(const char *);
99 static void init_reject(const char *);
100 static void copy_till(LINENUM, bool);
101 static bool spew_output(void);
102 static void dump_line(LINENUM, bool);
103 static bool patch_match(LINENUM, LINENUM, LINENUM);
104 static bool similar(const char *, const char *, int);
105 static void usage(void);
107 /* true if -E was specified on command line. */
108 static bool remove_empty_files = false;
110 /* true if -R was specified on command line. */
111 static bool reverse_flag_specified = false;
113 /* buffer holding the name of the rejected patch file. */
114 static char rejname[NAME_MAX + 1];
116 /* buffer for stderr */
117 static char serrbuf[BUFSIZ];
119 /* how many input lines have been irretractibly output */
120 static LINENUM last_frozen_line = 0;
122 static int Argc; /* guess */
124 static int Argc_last; /* for restarting plan_b */
125 static char **Argv_last;
127 static FILE *ofp = NULL; /* output file pointer */
128 static FILE *rejfp = NULL; /* reject file pointer */
130 static int filec = 0; /* how many file arguments? */
131 static LINENUM last_offset = 0;
132 static LINENUM maxfuzz = 2;
134 /* patch using ifdef, ifndef, etc. */
135 static bool do_defines = false;
137 static char if_defined[128];
139 static char not_defined[128];
141 static const char else_defined[] = "#else\n";
143 static char end_defined[128];
146 /* Apply a set of diffs as appropriate. */
149 main(int argc, char *argv[])
151 int error = 0, hunk, failed, i, fd;
152 LINENUM where = 0, newwhere, fuzz, mymaxfuzz;
156 setbuf(stderr, serrbuf);
157 for (i = 0; i < MAXFILEC; i++)
160 /* Cons up the names of the temporary files. */
161 if ((tmpdir = getenv("TMPDIR")) == NULL || *tmpdir == '\0')
163 for (i = strlen(tmpdir) - 1; i > 0 && tmpdir[i] == '/'; i--)
166 if (asprintf(&TMPOUTNAME, "%.*s/patchoXXXXXXXXXX", i, tmpdir) == -1)
167 fatal("cannot allocate memory");
168 if ((fd = mkstemp(TMPOUTNAME)) < 0)
169 pfatal("can't create %s", TMPOUTNAME);
172 if (asprintf(&TMPINNAME, "%.*s/patchiXXXXXXXXXX", i, tmpdir) == -1)
173 fatal("cannot allocate memory");
174 if ((fd = mkstemp(TMPINNAME)) < 0)
175 pfatal("can't create %s", TMPINNAME);
178 if (asprintf(&TMPREJNAME, "%.*s/patchrXXXXXXXXXX", i, tmpdir) == -1)
179 fatal("cannot allocate memory");
180 if ((fd = mkstemp(TMPREJNAME)) < 0)
181 pfatal("can't create %s", TMPREJNAME);
184 if (asprintf(&TMPPATNAME, "%.*s/patchpXXXXXXXXXX", i, tmpdir) == -1)
185 fatal("cannot allocate memory");
186 if ((fd = mkstemp(TMPPATNAME)) < 0)
187 pfatal("can't create %s", TMPPATNAME);
190 v = getenv("SIMPLE_BACKUP_SUFFIX");
192 simple_backup_suffix = v;
194 simple_backup_suffix = ORIGEXT;
201 if (backup_type == none) {
202 if ((v = getenv("PATCH_VERSION_CONTROL")) == NULL)
203 v = getenv("VERSION_CONTROL");
204 if (v != NULL || !posix)
205 backup_type = get_version(v); /* OK to pass NULL. */
208 /* make sure we clean up /tmp in case of disaster */
211 for (open_patch_file(filearg[1]); there_is_another_patch();
212 reinitialize_almost_everything()) {
213 /* for each patch in patch file */
215 warn_on_invalid_line = true;
218 outname = savestr(filearg[0]);
220 /* for ed script just up and do it and exit */
221 if (diff_type == ED_DIFF) {
225 /* initialize the patched file */
226 if (!skip_rest_of_patch)
227 init_output(TMPOUTNAME);
229 /* initialize reject file */
230 init_reject(TMPREJNAME);
232 /* find out where all the lines are */
233 if (!skip_rest_of_patch)
234 scan_input(filearg[0]);
236 /* from here on, open no standard i/o files, because malloc */
237 /* might misfire and we can't catch it easily */
239 /* apply each hunk of patch */
243 while (another_hunk()) {
246 mymaxfuzz = pch_context();
247 if (maxfuzz < mymaxfuzz)
249 if (!skip_rest_of_patch) {
251 where = locate_hunk(fuzz);
252 if (hunk == 1 && where == 0 && !force) {
253 /* dwim for reversed patch? */
256 say("Not enough memory to try swapped hunk! Assuming unswapped.\n");
261 where = locate_hunk(fuzz);
263 /* didn't find it swapped */
265 /* put it back to normal */
266 fatal("lost hunk on alloc error!\n");
268 } else if (noreverse) {
270 /* put it back to normal */
271 fatal("lost hunk on alloc error!\n");
273 say("Ignoring previously applied (or reversed) patch.\n");
274 skip_rest_of_patch = true;
277 say("%seversed (or previously applied) patch detected! %s -R.",
278 reverse ? "R" : "Unr",
279 reverse ? "Assuming" : "Ignoring");
281 ask("%seversed (or previously applied) patch detected! %s -R? [y] ",
282 reverse ? "R" : "Unr",
283 reverse ? "Assume" : "Ignore");
285 ask("Apply anyway? [n] ");
287 skip_rest_of_patch = true;
291 /* put it back to normal */
292 fatal("lost hunk on alloc error!\n");
296 } while (!skip_rest_of_patch && where == 0 &&
297 ++fuzz <= mymaxfuzz);
299 if (skip_rest_of_patch) { /* just got decided */
300 if (ferror(ofp) || fclose(ofp)) {
301 say("Error writing %s\n",
308 newwhere = pch_newfirst() + last_offset;
309 if (skip_rest_of_patch) {
313 say("Hunk #%d ignored at %ld.\n",
315 } else if (where == 0) {
319 say("Hunk #%d failed at %ld.\n",
324 say("Hunk #%d succeeded at %ld",
327 say(" with fuzz %ld", fuzz);
329 say(" (offset %ld line%s)",
331 last_offset == 1L ? "" : "s");
337 if (out_of_mem && using_plan_a) {
340 say("\n\nRan out of memory using Plan A--trying again...\n\n");
350 fatal("Internal error: hunk should not be 0\n");
352 /* finish spewing out the new file */
353 if (!skip_rest_of_patch && !spew_output()) {
354 say("Can't write %s\n", TMPOUTNAME);
358 /* and put the output where desired */
360 if (!skip_rest_of_patch) {
362 char *realout = outname;
365 if (move_file(TMPOUTNAME, outname) < 0) {
367 realout = TMPOUTNAME;
368 chmod(TMPOUTNAME, filemode);
370 chmod(outname, filemode);
372 if (remove_empty_files &&
373 stat(realout, &statbuf) == 0 &&
374 statbuf.st_size == 0) {
376 say("Removing %s (empty after patching).\n",
382 if (ferror(rejfp) || fclose(rejfp)) {
383 say("Error writing %s\n", rejname);
389 if (*rejname == '\0') {
390 if (strlcpy(rejname, outname,
391 sizeof(rejname)) >= sizeof(rejname))
392 fatal("filename %s is too long\n", outname);
393 if (strlcat(rejname, REJEXT,
394 sizeof(rejname)) >= sizeof(rejname))
395 fatal("filename %s is too long\n", outname);
397 if (skip_rest_of_patch) {
398 say("%d out of %d hunks ignored--saving rejects to %s\n",
399 failed, hunk, rejname);
401 say("%d out of %d hunks failed--saving rejects to %s\n",
402 failed, hunk, rejname);
404 if (!check_only && move_file(TMPREJNAME, rejname) < 0)
413 /* Prepare to find the next patch to do in the patch file. */
416 reinitialize_almost_everything(void)
422 last_frozen_line = 0;
439 reverse = reverse_flag_specified;
440 skip_rest_of_patch = false;
445 /* Process switches and filenames. */
448 get_some_switches(void)
450 const char *options = "b::B:cCd:D:eEfF:i:lnNo:p:r:RstuvV:x:z:";
451 static struct option longopts[] = {
452 {"backup", no_argument, 0, 'b'},
453 {"batch", no_argument, 0, 't'},
454 {"check", no_argument, 0, 'C'},
455 {"context", no_argument, 0, 'c'},
456 {"debug", required_argument, 0, 'x'},
457 {"directory", required_argument, 0, 'd'},
458 {"ed", no_argument, 0, 'e'},
459 {"force", no_argument, 0, 'f'},
460 {"forward", no_argument, 0, 'N'},
461 {"fuzz", required_argument, 0, 'F'},
462 {"ifdef", required_argument, 0, 'D'},
463 {"input", required_argument, 0, 'i'},
464 {"ignore-whitespace", no_argument, 0, 'l'},
465 {"normal", no_argument, 0, 'n'},
466 {"output", required_argument, 0, 'o'},
467 {"prefix", required_argument, 0, 'B'},
468 {"quiet", no_argument, 0, 's'},
469 {"reject-file", required_argument, 0, 'r'},
470 {"remove-empty-files", no_argument, 0, 'E'},
471 {"reverse", no_argument, 0, 'R'},
472 {"silent", no_argument, 0, 's'},
473 {"strip", required_argument, 0, 'p'},
474 {"suffix", required_argument, 0, 'z'},
475 {"unified", no_argument, 0, 'u'},
476 {"version", no_argument, 0, 'v'},
477 {"version-control", required_argument, 0, 'V'},
478 {"posix", no_argument, &posix, 1},
488 optreset = optind = 1;
489 while ((ch = getopt_long(Argc, Argv, options, longopts, NULL)) != -1) {
492 if (backup_type == none)
493 backup_type = numbered_existing;
497 say("Warning, the ``-b suffix'' option has been"
498 " obsoleted by the -z option.\n");
501 /* must directly follow 'b' case for backwards compat */
502 simple_backup_suffix = savestr(optarg);
505 origprae = savestr(optarg);
508 diff_type = CONTEXT_DIFF;
514 if (chdir(optarg) < 0)
515 pfatal("can't cd to %s", optarg);
519 if (!isalpha((unsigned char)*optarg) && *optarg != '_')
520 fatal("argument to -D is not an identifier\n");
521 snprintf(if_defined, sizeof if_defined,
522 "#ifdef %s\n", optarg);
523 snprintf(not_defined, sizeof not_defined,
524 "#ifndef %s\n", optarg);
525 snprintf(end_defined, sizeof end_defined,
526 "#endif /* %s */\n", optarg);
532 remove_empty_files = true;
538 maxfuzz = atoi(optarg);
541 if (++filec == MAXFILEC)
542 fatal("too many file arguments\n");
543 filearg[filec] = savestr(optarg);
549 diff_type = NORMAL_DIFF;
555 outname = savestr(optarg);
558 strippath = atoi(optarg);
561 if (strlcpy(rejname, optarg,
562 sizeof(rejname)) >= sizeof(rejname))
563 fatal("argument for -r is too long\n");
567 reverse_flag_specified = true;
576 diff_type = UNI_DIFF;
582 backup_type = get_version(optarg);
586 debug = atoi(optarg);
599 filearg[0] = savestr(*Argv++);
602 if (++filec == MAXFILEC)
603 fatal("too many file arguments\n");
604 filearg[filec] = savestr(*Argv++);
609 if (getenv("POSIXLY_CORRECT") != NULL)
617 "usage: patch [-bCcEeflNnRstuv] [-B backup-prefix] [-D symbol] [-d directory]\n"
618 " [-F max-fuzz] [-i patchfile] [-o out-file] [-p strip-count]\n"
619 " [-r rej-name] [-V t | nil | never] [-x number] [-z backup-ext]\n"
620 " [--posix] [origfile [patchfile]]\n"
621 " patch <patchfile\n");
622 my_exit(EXIT_SUCCESS);
626 * Attempt to find the right place to apply this hunk of patch.
629 locate_hunk(LINENUM fuzz)
631 LINENUM first_guess = pch_first() + last_offset;
633 LINENUM pat_lines = pch_ptrn_lines();
634 LINENUM max_pos_offset = input_lines - first_guess - pat_lines + 1;
635 LINENUM max_neg_offset = first_guess - last_frozen_line - 1 + pch_context();
637 if (pat_lines == 0) { /* null range matches always */
638 if (verbose && fuzz == 0 && (diff_type == CONTEXT_DIFF
639 || diff_type == NEW_CONTEXT_DIFF
640 || diff_type == UNI_DIFF)) {
641 say("Empty context always matches.\n");
643 return (first_guess);
645 if (max_neg_offset >= first_guess) /* do not try lines < 0 */
646 max_neg_offset = first_guess - 1;
647 if (first_guess <= input_lines && patch_match(first_guess, 0, fuzz))
649 for (offset = 1; ; offset++) {
650 bool check_after = (offset <= max_pos_offset);
651 bool check_before = (offset <= max_neg_offset);
653 if (check_after && patch_match(first_guess, offset, fuzz)) {
656 say("Offset changing from %ld to %ld\n",
657 last_offset, offset);
659 last_offset = offset;
660 return first_guess + offset;
661 } else if (check_before && patch_match(first_guess, -offset, fuzz)) {
664 say("Offset changing from %ld to %ld\n",
665 last_offset, -offset);
667 last_offset = -offset;
668 return first_guess - offset;
669 } else if (!check_before && !check_after)
674 /* We did not find the pattern, dump out the hunk so they can handle it. */
677 abort_context_hunk(void)
680 const LINENUM pat_end = pch_end();
682 * add in last_offset to guess the same as the previous successful
685 const LINENUM oldfirst = pch_first() + last_offset;
686 const LINENUM newfirst = pch_newfirst() + last_offset;
687 const LINENUM oldlast = oldfirst + pch_ptrn_lines() - 1;
688 const LINENUM newlast = newfirst + pch_repl_lines() - 1;
689 const char *stars = (diff_type >= NEW_CONTEXT_DIFF ? " ****" : "");
690 const char *minuses = (diff_type >= NEW_CONTEXT_DIFF ? " ----" : " -----");
692 fprintf(rejfp, "***************\n");
693 for (i = 0; i <= pat_end; i++) {
694 switch (pch_char(i)) {
696 if (oldlast < oldfirst)
697 fprintf(rejfp, "*** 0%s\n", stars);
698 else if (oldlast == oldfirst)
699 fprintf(rejfp, "*** %ld%s\n", oldfirst, stars);
701 fprintf(rejfp, "*** %ld,%ld%s\n", oldfirst,
705 if (newlast < newfirst)
706 fprintf(rejfp, "--- 0%s\n", minuses);
707 else if (newlast == newfirst)
708 fprintf(rejfp, "--- %ld%s\n", newfirst, minuses);
710 fprintf(rejfp, "--- %ld,%ld%s\n", newfirst,
714 fprintf(rejfp, "%s", pfetch(i));
720 fprintf(rejfp, "%c %s", pch_char(i), pfetch(i));
723 fatal("fatal internal error in abort_context_hunk\n");
729 rej_line(int ch, LINENUM i)
732 const char *line = pfetch(i);
736 fprintf(rejfp, "%c%s", ch, line);
737 if (len == 0 || line[len-1] != '\n')
738 fprintf(rejfp, "\n\\ No newline at end of file\n");
746 const LINENUM pat_end = pch_end();
747 const LINENUM oldfirst = pch_first() + last_offset;
748 const LINENUM newfirst = pch_newfirst() + last_offset;
750 if (diff_type != UNI_DIFF) {
751 abort_context_hunk();
755 for (i = 0; i <= pat_end; i++) {
756 if (pch_char(i) == '=') {
762 fprintf(rejfp, "malformed hunk: no split found\n");
767 fprintf(rejfp, "@@ -%ld,%ld +%ld,%ld @@\n",
768 pch_ptrn_lines() ? oldfirst : 0,
769 pch_ptrn_lines(), newfirst, pch_repl_lines());
770 while (i < split || j <= pat_end) {
771 ch1 = i < split ? pch_char(i) : -1;
772 ch2 = j <= pat_end ? pch_char(j) : -1;
776 } else if (ch1 == ' ' && ch2 == ' ') {
780 } else if (ch1 == '!' && ch2 == '!') {
781 while (i < split && ch1 == '!') {
784 ch1 = i < split ? pch_char(i) : -1;
786 while (j <= pat_end && ch2 == '!') {
789 ch2 = j <= pat_end ? pch_char(j) : -1;
791 } else if (ch1 == '*') {
793 } else if (ch2 == '+' || ch2 == ' ') {
797 fprintf(rejfp, "internal error on (%ld %ld %ld)\n",
806 /* We found where to apply it (we hope), so do it. */
809 apply_hunk(LINENUM where)
812 const LINENUM lastline = pch_ptrn_lines();
813 LINENUM new = lastline + 1;
818 int def_state = OUTSIDE;
819 const LINENUM pat_end = pch_end();
822 while (pch_char(new) == '=' || pch_char(new) == '\n')
825 while (old <= lastline) {
826 if (pch_char(old) == '-') {
827 copy_till(where + old - 1, false);
829 if (def_state == OUTSIDE) {
830 fputs(not_defined, ofp);
831 def_state = IN_IFNDEF;
832 } else if (def_state == IN_IFDEF) {
833 fputs(else_defined, ofp);
836 fputs(pfetch(old), ofp);
840 } else if (new > pat_end) {
842 } else if (pch_char(new) == '+') {
843 copy_till(where + old - 1, false);
845 if (def_state == IN_IFNDEF) {
846 fputs(else_defined, ofp);
848 } else if (def_state == OUTSIDE) {
849 fputs(if_defined, ofp);
850 def_state = IN_IFDEF;
853 fputs(pfetch(new), ofp);
855 } else if (pch_char(new) != pch_char(old)) {
856 say("Out-of-sync patch, lines %ld,%ld--mangled text or line numbers, maybe?\n",
857 pch_hunk_beg() + old,
858 pch_hunk_beg() + new);
860 say("oldchar = '%c', newchar = '%c'\n",
861 pch_char(old), pch_char(new));
864 } else if (pch_char(new) == '!') {
865 copy_till(where + old - 1, false);
867 fputs(not_defined, ofp);
868 def_state = IN_IFNDEF;
870 while (pch_char(old) == '!') {
872 fputs(pfetch(old), ofp);
878 fputs(else_defined, ofp);
881 while (pch_char(new) == '!') {
882 fputs(pfetch(new), ofp);
886 if (pch_char(new) != ' ')
887 fatal("Internal error: expected ' '\n");
890 if (do_defines && def_state != OUTSIDE) {
891 fputs(end_defined, ofp);
896 if (new <= pat_end && pch_char(new) == '+') {
897 copy_till(where + old - 1, false);
899 if (def_state == OUTSIDE) {
900 fputs(if_defined, ofp);
901 def_state = IN_IFDEF;
902 } else if (def_state == IN_IFNDEF) {
903 fputs(else_defined, ofp);
907 while (new <= pat_end && pch_char(new) == '+') {
908 fputs(pfetch(new), ofp);
912 if (do_defines && def_state != OUTSIDE) {
913 fputs(end_defined, ofp);
921 init_output(const char *name)
923 ofp = fopen(name, "w");
925 pfatal("can't create %s", name);
929 * Open a file to put hunks we can't locate.
932 init_reject(const char *name)
934 rejfp = fopen(name, "w");
936 pfatal("can't create %s", name);
940 * Copy input file to output, up to wherever hunk is to be applied.
941 * If endoffile is true, treat the last line specially since it may
945 copy_till(LINENUM lastline, bool endoffile)
947 if (last_frozen_line > lastline)
948 fatal("misordered hunks! output would be garbled\n");
949 while (last_frozen_line < lastline) {
950 if (++last_frozen_line == lastline && endoffile)
951 dump_line(last_frozen_line, !last_line_missing_eol);
953 dump_line(last_frozen_line, true);
958 * Finish copying the input file to the output file.
967 say("il=%ld lfl=%ld\n", input_lines, last_frozen_line);
970 copy_till(input_lines, true); /* dump remainder of file */
971 rv = ferror(ofp) == 0 && fclose(ofp) == 0;
977 * Copy one line from input to output.
980 dump_line(LINENUM line, bool write_newline)
987 /* Note: string is not NUL terminated. */
988 for (; *s != '\n'; s++)
995 * Does the patch pattern match at line base+offset?
998 patch_match(LINENUM base, LINENUM offset, LINENUM fuzz)
1000 LINENUM pline = 1 + fuzz;
1002 LINENUM pat_lines = pch_ptrn_lines() - fuzz;
1003 const char *ilineptr;
1004 const char *plineptr;
1007 for (iline = base + offset + fuzz; pline <= pat_lines; pline++, iline++) {
1008 ilineptr = ifetch(iline, offset >= 0);
1009 if (ilineptr == NULL)
1011 plineptr = pfetch(pline);
1012 plinelen = pch_line_len(pline);
1014 if (!similar(ilineptr, plineptr, plinelen))
1016 } else if (strnNE(ilineptr, plineptr, plinelen))
1018 if (iline == input_lines) {
1020 * We are looking at the last line of the file.
1021 * If the file has no eol, the patch line should
1022 * not have one either and vice-versa. Note that
1025 if (last_line_missing_eol) {
1026 if (plineptr[plinelen - 1] == '\n')
1029 if (plineptr[plinelen - 1] != '\n')
1038 * Do two lines match with canonicalized white space?
1041 similar(const char *a, const char *b, int len)
1044 if (isspace((unsigned char)*b)) { /* whitespace (or \n) to match? */
1045 if (!isspace((unsigned char)*a)) /* no corresponding whitespace? */
1047 while (len && isspace((unsigned char)*b) && *b != '\n')
1048 b++, len--; /* skip pattern whitespace */
1049 while (isspace((unsigned char)*a) && *a != '\n')
1050 a++; /* skip target whitespace */
1051 if (*a == '\n' || *b == '\n')
1052 return (*a == *b); /* should end in sync */
1053 } else if (*a++ != *b++) /* match non-whitespace chars */
1056 len--; /* probably not necessary */
1058 return true; /* actually, this is not reached */
1059 /* since there is always a \n */