1 /* vi: set sw=4 ts=4: */
3 * Mini diff implementation for busybox, adapted from OpenBSD diff.
5 * Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
6 * Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
8 * Sponsored in part by the Defense Advanced Research Projects
9 * Agency (DARPA) and Air Force Research Laboratory, Air Force
10 * Materiel Command, USAF, under agreement number F39502-99-1-0512.
12 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
17 #define FSIZE_MAX 32768
22 #define D_HEADER 1 /* Print a header/footer between files */
23 #define D_EMPTY1 2 /* Treat first file as empty (/dev/null) */
24 #define D_EMPTY2 4 /* Treat second file as empty (/dev/null) */
27 * Status values for print_status() and diffreg() return values
29 * D_SAME - files are the same
30 * D_DIFFER - files differ
31 * D_BINARY - binary files differ
32 * D_COMMON - subdirectory common to both dirs
33 * D_ONLY - file only exists in one dir
34 * D_MISMATCH1 - path1 a dir, path2 a file
35 * D_MISMATCH2 - path1 a file, path2 a dir
36 * D_ERROR - error occurred
37 * D_SKIPPED1 - skipped path1 as it is a special file
38 * D_SKIPPED2 - skipped path2 as it is a special file
42 #define D_DIFFER (1<<0)
43 #define D_BINARY (1<<1)
44 #define D_COMMON (1<<2)
46 #define D_MISMATCH1 (1<<4)
47 #define D_MISMATCH2 (1<<5)
48 #define D_ERROR (1<<6)
49 #define D_SKIPPED1 (1<<7)
50 #define D_SKIPPED2 (1<<8)
52 /* Command line options */
63 #define FLAG_t (1<<10)
64 #define FLAG_T (1<<11)
65 #define FLAG_U (1<<12)
66 #define FLAG_w (1<<13)
68 /* XXX: FIXME: the following variables should be static, but gcc currently
69 * creates a much bigger object if we do this. [which version of gcc? --vda] */
71 char *start, *label[2];
72 struct stat stb1, stb2;
88 * The following struct is used to record change information
89 * doing a "context" or "unified" diff. (see routine "change" to
90 * understand the highly mnemonic field names)
93 int a; /* start line in old file */
94 int b; /* end line in old file */
95 int c; /* start line in new file */
96 int d; /* end line in new file */
99 static int *J; /* will be overlaid on class */
100 static int *class; /* will be overlaid on file[0] */
101 static int *klist; /* will be overlaid on file[0] after class */
102 static int *member; /* will be overlaid on file[1] */
105 static int pref, suff; /* length of prefix and suffix */
107 static int anychange;
108 static long *ixnew; /* will be overlaid on file[1] */
109 static long *ixold; /* will be overlaid on klist */
110 static struct cand *clist; /* merely a free storage pot for candidates */
111 static int clistlen; /* the length of clist */
112 static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
113 static struct context_vec *context_vec_start;
114 static struct context_vec *context_vec_end;
115 static struct context_vec *context_vec_ptr;
118 static void print_only(const char *path, size_t dirlen, const char *entry)
122 printf("Only in %.*s: %s\n", (int) dirlen, path, entry);
126 static void print_status(int val, char *path1, char *path2, char *entry)
128 const char *const _entry = entry ? entry : "";
129 char *_path1 = entry ? concat_path_file(path1, _entry) : path1;
130 char *_path2 = entry ? concat_path_file(path2, _entry) : path2;
134 print_only(path1, strlen(path1), entry);
137 printf("Common subdirectories: %s and %s\n", _path1, _path2);
140 printf("Binary files %s and %s differ\n", _path1, _path2);
143 if (option_mask32 & FLAG_q)
144 printf("Files %s and %s differ\n", _path1, _path2);
147 if (option_mask32 & FLAG_s)
148 printf("Files %s and %s are identical\n", _path1, _path2);
151 printf("File %s is a %s while file %s is a %s\n",
152 _path1, "directory", _path2, "regular file");
155 printf("File %s is a %s while file %s is a %s\n",
156 _path1, "regular file", _path2, "directory");
159 printf("File %s is not a regular file or directory and was skipped\n",
163 printf("File %s is not a regular file or directory and was skipped\n",
175 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
177 static int readhash(FILE * f)
184 if (!(option_mask32 & FLAG_b) && !(option_mask32 & FLAG_w)) {
186 for (i = 0; (t = getc(f)) != '\n'; i++) {
194 for (i = 0; (t = getc(f)) != '\n'; i++) {
204 switch (t = getc(f)) {
213 if (space && !(option_mask32 & FLAG_w)) {
231 * There is a remote possibility that we end up with a zero sum.
232 * Zero is used as an EOF marker, so return 1 instead.
234 return (sum == 0 ? 1 : sum);
239 * Check to see if the given files differ.
240 * Returns 0 if they are the same, 1 if different, and -1 on error.
242 static int files_differ(FILE * f1, FILE * f2, int flags)
246 if ((flags & (D_EMPTY1 | D_EMPTY2)) || stb1.st_size != stb2.st_size ||
247 (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT))
250 i = fread(bb_common_bufsiz1, 1, BUFSIZ/2, f1);
251 j = fread(bb_common_bufsiz1 + BUFSIZ/2, 1, BUFSIZ/2, f2);
254 if (i == 0 && j == 0) {
255 if (ferror(f1) || ferror(f2))
259 if (memcmp(bb_common_bufsiz1,
260 bb_common_bufsiz1 + BUFSIZ/2, i) != 0)
266 static void prepare(int i, FILE * fd, off_t filesize)
274 sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;
278 p = xmalloc((sz + 3) * sizeof(struct line));
279 for (j = 0; (h = readhash(fd));) {
282 p = xrealloc(p, (sz + 3) * sizeof(struct line));
291 static void prune(void)
295 for (pref = 0; pref < len[0] && pref < len[1] &&
296 file[0][pref + 1].value == file[1][pref + 1].value; pref++);
297 for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
298 file[0][len[0] - suff].value == file[1][len[1] - suff].value;
300 for (j = 0; j < 2; j++) {
301 sfile[j] = file[j] + pref;
302 slen[j] = len[j] - pref - suff;
303 for (i = 0; i <= slen[j]; i++)
304 sfile[j][i].serial = i;
309 static void equiv(struct line *a, int n, struct line *b, int m, int *c)
314 while (i <= n && j <= m) {
315 if (a[i].value < b[j].value)
317 else if (a[i].value == b[j].value)
328 while (b[j + 1].value == b[j].value) {
337 static int isqrt(int n)
349 } while ((x - y) > 1 || (x - y) < -1);
355 static int newcand(int x, int y, int pred)
359 if (clen == clistlen) {
360 clistlen = clistlen * 11 / 10;
361 clist = xrealloc(clist, clistlen * sizeof(struct cand));
371 static int search(int *c, int k, int y)
375 if (clist[c[k]].y < y) /* quick look for typical case */
395 static int stone(int *a, int n, int *b, int *c)
399 unsigned int numtries;
401 #if ENABLE_FEATURE_DIFF_MINIMAL
402 const unsigned int bound =
403 (option_mask32 & FLAG_d) ? UINT_MAX : MAX(256, isqrt(n));
405 const unsigned int bound = MAX(256, isqrt(n));
408 c[0] = newcand(0, 0, 0);
409 for (i = 1; i <= n; i++) {
418 if (y <= clist[oldc].y)
424 if (clist[c[l]].y <= y)
427 c[l] = newcand(i, y, oldc);
432 c[l] = newcand(i, y, oldc);
436 } while ((y = b[++j]) > 0 && numtries < bound);
442 static void unravel(int p)
447 for (i = 0; i <= len[0]; i++)
448 J[i] = i <= pref ? i : i > len[0] - suff ? i + len[1] - len[0] : 0;
449 for (q = clist + p; q->y != 0; q = clist + q->pred)
450 J[q->x + pref] = q->y + pref;
454 static void unsort(struct line *f, int l, int *b)
458 a = xmalloc((l + 1) * sizeof(int));
459 for (i = 1; i <= l; i++)
460 a[f[i].serial] = f[i].value;
461 for (i = 1; i <= l; i++)
467 static int skipline(FILE * f)
471 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
478 * Check does double duty:
479 * 1. ferret out any fortuitous correspondences due
480 * to confounding by hashing (which result in "jackpot")
481 * 2. collect random access indexes to the two files
483 static void check(FILE * f1, FILE * f2)
485 int i, j, jackpot, c, d;
491 ixold[0] = ixnew[0] = 0;
494 for (i = 1; i <= len[0]; i++) {
496 ixold[i] = ctold += skipline(f1);
500 ixnew[j] = ctnew += skipline(f2);
503 if ((option_mask32 & FLAG_b) || (option_mask32 & FLAG_w)
504 || (option_mask32 & FLAG_i)) {
509 * GNU diff ignores a missing newline
510 * in one file if bflag || wflag.
512 if (((option_mask32 & FLAG_b) || (option_mask32 & FLAG_w)) &&
513 ((c == EOF && d == '\n') || (c == '\n' && d == EOF))) {
518 if ((option_mask32 & FLAG_b) && isspace(c) && isspace(d)) {
523 } while (isspace(c = getc(f1)));
528 } while (isspace(d = getc(f2)));
529 } else if (option_mask32 & FLAG_w) {
530 while (isspace(c) && c != '\n') {
534 while (isspace(d) && d != '\n') {
542 if (c != '\n' && c != EOF)
543 ctold += skipline(f1);
544 if (d != '\n' && c != EOF)
545 ctnew += skipline(f2);
548 if (c == '\n' || c == EOF)
555 if ((c = getc(f1)) != (d = getc(f2))) {
557 if (c != '\n' && c != EOF)
558 ctold += skipline(f1);
559 if (d != '\n' && c != EOF)
560 ctnew += skipline(f2);
563 if (c == '\n' || c == EOF)
571 for (; j <= len[1]; j++)
572 ixnew[j] = ctnew += skipline(f2);
576 /* shellsort CACM #201 */
577 static void sort(struct line *a, int n)
579 struct line *ai, *aim, w;
584 for (j = 1; j <= n; j *= 2)
586 for (m /= 2; m != 0; m /= 2) {
588 for (j = 1; j <= k; j++) {
589 for (ai = &a[j]; ai > a; ai -= m) {
592 break; /* wraparound */
593 if (aim->value > ai[0].value ||
594 (aim->value == ai[0].value && aim->serial > ai[0].serial))
596 w.value = ai[0].value;
597 ai[0].value = aim->value;
598 aim->value = w.value;
599 w.serial = ai[0].serial;
600 ai[0].serial = aim->serial;
601 aim->serial = w.serial;
608 static void uni_range(int a, int b)
611 printf("%d,%d", a, b - a + 1);
619 static int fetch(long *f, int a, int b, FILE * lb, int ch)
621 int i, j, c, lastc, col, nc;
625 for (i = a; i <= b; i++) {
626 fseek(lb, f[i - 1], SEEK_SET);
627 nc = f[i] - f[i - 1];
630 if (option_mask32 & FLAG_T)
634 for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
635 if ((c = getc(lb)) == EOF) {
636 puts("\n\\ No newline at end of file");
639 if (c == '\t' && (option_mask32 & FLAG_t)) {
653 static int asciifile(FILE * f)
655 #if ENABLE_FEATURE_DIFF_BINARY
659 if ((option_mask32 & FLAG_a) || f == NULL)
662 #if ENABLE_FEATURE_DIFF_BINARY
664 cnt = fread(bb_common_bufsiz1, 1, BUFSIZ, f);
665 for (i = 0; i < cnt; i++) {
666 if (!isprint(bb_common_bufsiz1[i])
667 && !isspace(bb_common_bufsiz1[i])) {
676 /* dump accumulated "unified" diff changes */
677 static void dump_unified_vec(FILE * f1, FILE * f2)
679 struct context_vec *cvp = context_vec_start;
680 int lowa, upb, lowc, upd;
684 if (context_vec_start > context_vec_ptr)
688 lowa = MAX(1, cvp->a - context);
689 upb = MIN(len[0], context_vec_ptr->b + context);
690 lowc = MAX(1, cvp->c - context);
691 upd = MIN(len[1], context_vec_ptr->d + context);
693 fputs("@@ -", stdout);
694 uni_range(lowa, upb);
696 uni_range(lowc, upd);
697 fputs(" @@", stdout);
701 * Output changes in "unified" diff format--the old and new lines
702 * are printed together.
704 for (; cvp <= context_vec_ptr; cvp++) {
711 * c: both new and old changes
712 * d: only changes in the old file
713 * a: only changes in the new file
715 if (a <= b && c <= d)
718 ch = (a <= b) ? 'd' : 'a';
719 if (ch == 'c' || ch == 'd') {
720 fetch(ixold, lowa, a - 1, f1, ' ');
721 fetch(ixold, a, b, f1, '-');
724 fetch(ixnew, lowc, c - 1, f2, ' ');
725 if (ch == 'c' || ch == 'a')
726 fetch(ixnew, c, d, f2, '+');
730 fetch(ixnew, d + 1, upd, f2, ' ');
732 context_vec_ptr = context_vec_start - 1;
736 static void print_header(const char *file1, const char *file2)
738 if (label[0] != NULL)
739 printf("%s %s\n", "---", label[0]);
741 printf("%s %s\t%s", "---", file1, ctime(&stb1.st_mtime));
742 if (label[1] != NULL)
743 printf("%s %s\n", "+++", label[1]);
745 printf("%s %s\t%s", "+++", file2, ctime(&stb2.st_mtime));
750 * Indicate that there is a difference between lines a and b of the from file
751 * to get to lines c to d of the to file. If a is greater than b then there
752 * are no lines in the from file involved and this means that there were
753 * lines appended (beginning at b). If c is greater than d then there are
754 * lines missing from the to file.
756 static void change(char *file1, FILE * f1, char *file2, FILE * f2, int a,
759 static size_t max_context = 64;
761 if ((a > b && c > d) || (option_mask32 & FLAG_q)) {
767 * Allocate change records as needed.
769 if (context_vec_ptr == context_vec_end - 1) {
770 ptrdiff_t offset = context_vec_ptr - context_vec_start;
773 context_vec_start = xrealloc(context_vec_start,
775 sizeof(struct context_vec));
776 context_vec_end = context_vec_start + max_context;
777 context_vec_ptr = context_vec_start + offset;
779 if (anychange == 0) {
781 * Print the context/unidiff header first time through.
783 print_header(file1, file2);
784 } else if (a > context_vec_ptr->b + (2 * context) + 1 &&
785 c > context_vec_ptr->d + (2 * context) + 1) {
787 * If this change is more than 'context' lines from the
788 * previous change, dump the record and reset it.
790 dump_unified_vec(f1, f2);
793 context_vec_ptr->a = a;
794 context_vec_ptr->b = b;
795 context_vec_ptr->c = c;
796 context_vec_ptr->d = d;
801 static void output(char *file1, FILE * f1, char *file2, FILE * f2)
803 /* Note that j0 and j1 can't be used as they are defined in math.h.
804 * This also allows the rather amusing variable 'j00'... */
805 int m, i0, i1, j00, j01;
811 J[m + 1] = len[1] + 1;
812 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
813 while (i0 <= m && J[i0] == J[i0 - 1] + 1)
817 while (i1 < m && J[i1 + 1] == 0)
821 change(file1, f1, file2, f2, i0, i1, j00, j01);
824 change(file1, f1, file2, f2, 1, 0, 1, len[1]);
826 if (anychange != 0 && !(option_mask32 & FLAG_q)) {
827 dump_unified_vec(f1, f2);
832 * The following code uses an algorithm due to Harold Stone,
833 * which finds a pair of longest identical subsequences in
836 * The major goal is to generate the match vector J.
837 * J[i] is the index of the line in file1 corresponding
838 * to line i file0. J[i] = 0 if there is no
839 * such line in file1.
841 * Lines are hashed so as to work in core. All potential
842 * matches are located by sorting the lines of each file
843 * on the hash (called ``value''). In particular, this
844 * collects the equivalence classes in file1 together.
845 * Subroutine equiv replaces the value of each line in
846 * file0 by the index of the first element of its
847 * matching equivalence in (the reordered) file1.
848 * To save space equiv squeezes file1 into a single
849 * array member in which the equivalence classes
850 * are simply concatenated, except that their first
851 * members are flagged by changing sign.
853 * Next the indices that point into member are unsorted into
854 * array class according to the original order of file0.
856 * The cleverness lies in routine stone. This marches
857 * through the lines of file0, developing a vector klist
858 * of "k-candidates". At step i a k-candidate is a matched
859 * pair of lines x,y (x in file0 y in file1) such that
860 * there is a common subsequence of length k
861 * between the first i lines of file0 and the first y
862 * lines of file1, but there is no such subsequence for
863 * any smaller y. x is the earliest possible mate to y
864 * that occurs in such a subsequence.
866 * Whenever any of the members of the equivalence class of
867 * lines in file1 matable to a line in file0 has serial number
868 * less than the y of some k-candidate, that k-candidate
869 * with the smallest such y is replaced. The new
870 * k-candidate is chained (via pred) to the current
871 * k-1 candidate so that the actual subsequence can
872 * be recovered. When a member has serial number greater
873 * that the y of all k-candidates, the klist is extended.
874 * At the end, the longest subsequence is pulled out
875 * and placed in the array J by unravel
877 * With J in hand, the matches there recorded are
878 * checked against reality to assure that no spurious
879 * matches have crept in due to hashing. If they have,
880 * they are broken, and "jackpot" is recorded--a harmless
881 * matter except that a true match for a spuriously
882 * mated line may now be unnecessarily reported as a change.
884 * Much of the complexity of the program comes simply
885 * from trying to minimize core utilization and
886 * maximize the range of doable problems by dynamically
887 * allocating what is needed and reusing what is not.
888 * The core requirements for problems larger than somewhat
889 * are (in words) 2*length(file0) + length(file1) +
890 * 3*(number of k-candidates installed), typically about
891 * 6n words for files of length n.
893 static int diffreg(char *ofile1, char *ofile2, int flags)
895 char *file1 = ofile1;
896 char *file2 = ofile2;
903 context_vec_ptr = context_vec_start - 1;
905 if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
906 return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
907 if (LONE_DASH(file1) && LONE_DASH(file2))
911 if (flags & D_EMPTY1)
912 f1 = xfopen(bb_dev_null, "r");
913 else if (NOT_LONE_DASH(file1))
914 f1 = xfopen(file1, "r");
917 if (flags & D_EMPTY2)
918 f2 = xfopen(bb_dev_null, "r");
919 else if (NOT_LONE_DASH(file2))
920 f2 = xfopen(file2, "r");
922 i = files_differ(f1, f2, flags);
925 else if (i != 1) { /* 1 == ok */
931 if (!asciifile(f1) || !asciifile(f2)) {
937 prepare(0, f1, stb1.st_size);
938 prepare(1, f2, stb2.st_size);
940 sort(sfile[0], slen[0]);
941 sort(sfile[1], slen[1]);
943 member = (int *) file[1];
944 equiv(sfile[0], slen[0], sfile[1], slen[1], member);
945 member = xrealloc(member, (slen[1] + 2) * sizeof(int));
947 class = (int *) file[0];
948 unsort(sfile[0], slen[0], class);
949 class = xrealloc(class, (slen[0] + 2) * sizeof(int));
951 klist = xmalloc((slen[0] + 2) * sizeof(int));
954 clist = xmalloc(clistlen * sizeof(struct cand));
955 i = stone(class, slen[0], member, klist);
959 J = xrealloc(J, (len[0] + 2) * sizeof(int));
964 ixold = xrealloc(ixold, (len[0] + 2) * sizeof(long));
965 ixnew = xrealloc(ixnew, (len[1] + 2) * sizeof(long));
967 output(file1, f1, file2, f2);
987 #if ENABLE_FEATURE_DIFF_DIR
988 static void do_diff(char *dir1, char *path1, char *dir2, char *path2)
990 int flags = D_HEADER;
993 char *fullpath1 = xasprintf("%s/%s", dir1, path1);
994 char *fullpath2 = xasprintf("%s/%s", dir2, path2);
996 if (stat(fullpath1, &stb1) != 0) {
998 memset(&stb1, 0, sizeof(stb1));
999 fullpath1 = xasprintf("%s/%s", dir1, path2);
1001 if (stat(fullpath2, &stb2) != 0) {
1003 memset(&stb2, 0, sizeof(stb2));
1004 stb2.st_mode = stb1.st_mode;
1005 fullpath2 = xasprintf("%s/%s", dir2, path1);
1008 if (stb1.st_mode == 0)
1009 stb1.st_mode = stb2.st_mode;
1011 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1012 printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
1016 if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
1018 else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
1021 val = diffreg(fullpath1, fullpath2, flags);
1023 print_status(val, fullpath1, fullpath2, NULL);
1028 #if ENABLE_FEATURE_DIFF_DIR
1029 static int dir_strcmp(const void *p1, const void *p2)
1031 return strcmp(*(char *const *) p1, *(char *const *) p2);
1035 /* This function adds a filename to dl, the directory listing. */
1036 static int add_to_dirlist(const char *filename,
1037 struct stat ATTRIBUTE_UNUSED * sb, void *userdata,
1038 int depth ATTRIBUTE_UNUSED)
1041 dl = xrealloc(dl, dl_count * sizeof(char *));
1042 dl[dl_count - 1] = xstrdup(filename);
1043 if (option_mask32 & FLAG_r) {
1044 int *pp = (int *) userdata;
1045 int path_len = *pp + 1;
1047 dl[dl_count - 1] = &(dl[dl_count - 1])[path_len];
1053 /* This returns a sorted directory listing. */
1054 static char **get_dir(char *path)
1059 /* If -r has been set, then the recursive_action function will be
1060 * used. Unfortunately, this outputs the root directory along with
1061 * the recursed paths, so use void *userdata to specify the string
1062 * length of the root directory. It can then be removed in
1063 * add_to_dirlist. */
1065 int path_len = strlen(path);
1066 void *userdata = &path_len;
1068 /* Reset dl_count - there's no need to free dl as xrealloc does
1069 * the job nicely. */
1072 /* Now fill dl with a listing. */
1073 if (option_mask32 & FLAG_r)
1074 recursive_action(path, TRUE, TRUE, FALSE, add_to_dirlist, NULL,
1080 dp = warn_opendir(path);
1081 while ((ep = readdir(dp))) {
1082 if ((!strcmp(ep->d_name, "..")) || (!strcmp(ep->d_name, ".")))
1084 add_to_dirlist(ep->d_name, NULL, NULL, 0);
1089 /* Sort dl alphabetically. */
1090 qsort(dl, dl_count, sizeof(char *), dir_strcmp);
1092 /* Copy dl so that we can return it. */
1093 retval = xmalloc(dl_count * sizeof(char *));
1094 for (i = 0; i < dl_count; i++)
1095 retval[i] = xstrdup(dl[i]);
1101 static void diffdir(char *p1, char *p2)
1103 char **dirlist1, **dirlist2;
1105 int dirlist1_count, dirlist2_count;
1108 /* Check for trailing slashes. */
1110 dp1 = last_char_is(p1, '/');
1113 dp2 = last_char_is(p2, '/');
1117 /* Get directory listings for p1 and p2. */
1119 dirlist1 = get_dir(p1);
1120 dirlist1_count = dl_count;
1121 dirlist1[dirlist1_count] = NULL;
1122 dirlist2 = get_dir(p2);
1123 dirlist2_count = dl_count;
1124 dirlist2[dirlist2_count] = NULL;
1126 /* If -S was set, find the starting point. */
1128 while (*dirlist1 != NULL && strcmp(*dirlist1, start) < 0)
1130 while (*dirlist2 != NULL && strcmp(*dirlist2, start) < 0)
1132 if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
1133 bb_error_msg(bb_msg_invalid_arg, "NULL", "-S");
1136 /* Now that both dirlist1 and dirlist2 contain sorted directory
1137 * listings, we can start to go through dirlist1. If both listings
1138 * contain the same file, then do a normal diff. Otherwise, behaviour
1139 * is determined by whether the -N flag is set. */
1140 while (*dirlist1 != NULL || *dirlist2 != NULL) {
1143 pos = dp1 == NULL ? 1 : dp2 == NULL ? -1 : strcmp(dp1, dp2);
1145 do_diff(p1, dp1, p2, dp2);
1148 } else if (pos < 0) {
1149 if (option_mask32 & FLAG_N)
1150 do_diff(p1, dp1, p2, NULL);
1152 print_only(p1, strlen(p1) + 1, dp1);
1155 if (option_mask32 & FLAG_N)
1156 do_diff(p1, NULL, p2, dp2);
1158 print_only(p2, strlen(p2) + 1, dp2);
1166 int diff_main(int argc, char **argv)
1171 llist_t *L_arg = NULL;
1173 opt_complementary = "L::";
1174 getopt32(argc, argv, "abdiL:NqrsS:tTU:wu"
1175 "p" /* ignored (for compatibility) */,
1176 &L_arg, &start, &U_opt);
1178 if (option_mask32 & FLAG_L) {
1180 if (label[0] == NULL)
1181 label[0] = L_arg->data;
1182 else if (label[1] == NULL)
1183 label[1] = L_arg->data;
1187 L_arg = L_arg->link;
1190 /* If both label[0] and label[1] were set, they need to be swapped. */
1191 if (label[0] && label[1]) {
1195 label[1] = label[0];
1200 context = 3; /* This is the default number of lines of context. */
1201 if (option_mask32 & FLAG_U) {
1202 context = xatou_range(U_opt, 1, INT_MAX);
1208 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
1209 * driver routine. Both drivers use the contents of stb1 and stb2.
1212 bb_error_msg("missing filename");
1215 if (LONE_DASH(argv[0])) {
1216 fstat(STDIN_FILENO, &stb1);
1219 xstat(argv[0], &stb1);
1220 if (LONE_DASH(argv[1])) {
1221 fstat(STDIN_FILENO, &stb2);
1224 xstat(argv[1], &stb2);
1225 if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
1226 bb_error_msg_and_die("can't compare - to a directory");
1227 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1228 #if ENABLE_FEATURE_DIFF_DIR
1229 diffdir(argv[0], argv[1]);
1231 bb_error_msg_and_die("directory comparison not supported");
1234 if (S_ISDIR(stb1.st_mode)) {
1235 argv[0] = concat_path_file(argv[0], argv[1]);
1236 xstat(argv[0], &stb1);
1238 if (S_ISDIR(stb2.st_mode)) {
1239 argv[1] = concat_path_file(argv[1], argv[0]);
1240 xstat(argv[1], &stb2);
1242 print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1], NULL);