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 /* The following variables should be static, but gcc currently
69 * creates a much bigger object if we do this. [which version of gcc? --vda] */
70 /* 4.x, IIRC also 3.x --bernhard */
71 /* Works for gcc 3.4.3. Sizes without and with "static":
72 # size busybox.t[34]/coreutils/diff.o
73 text data bss dec hex filename
74 6969 8 305 7282 1c72 busybox.t3/coreutils/diff.o
75 6969 8 305 7282 1c72 busybox.t4/coreutils/diff.o
78 /* This is the default number of lines of context. */
79 static int context = 3;
82 static const char *label1;
83 static const char *label2;
84 static struct stat stb1, stb2;
85 USE_FEATURE_DIFF_DIR(static char **dl;)
86 USE_FEATURE_DIFF_DIR(static int dl_count;)
100 * The following struct is used to record change information
101 * doing a "context" or "unified" diff. (see routine "change" to
102 * understand the highly mnemonic field names)
105 int a; /* start line in old file */
106 int b; /* end line in old file */
107 int c; /* start line in new file */
108 int d; /* end line in new file */
111 static int *J; /* will be overlaid on class */
112 static int *class; /* will be overlaid on file[0] */
113 static int *klist; /* will be overlaid on file[0] after class */
114 static int *member; /* will be overlaid on file[1] */
117 static int pref, suff; /* length of prefix and suffix */
119 static bool anychange;
120 static long *ixnew; /* will be overlaid on file[1] */
121 static long *ixold; /* will be overlaid on klist */
122 static struct cand *clist; /* merely a free storage pot for candidates */
123 static int clistlen; /* the length of clist */
124 static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
125 static struct context_vec *context_vec_start;
126 static struct context_vec *context_vec_end;
127 static struct context_vec *context_vec_ptr;
130 static void print_only(const char *path, size_t dirlen, const char *entry)
134 printf("Only in %.*s: %s\n", (int) dirlen, path, entry);
138 static void print_status(int val, char *path1, char *path2, char *entry)
140 const char * const _entry = entry ? entry : "";
141 char * const _path1 = entry ? concat_path_file(path1, _entry) : path1;
142 char * const _path2 = entry ? concat_path_file(path2, _entry) : path2;
146 print_only(path1, strlen(path1), entry);
149 printf("Common subdirectories: %s and %s\n", _path1, _path2);
152 printf("Binary files %s and %s differ\n", _path1, _path2);
155 if (option_mask32 & FLAG_q)
156 printf("Files %s and %s differ\n", _path1, _path2);
159 if (option_mask32 & FLAG_s)
160 printf("Files %s and %s are identical\n", _path1, _path2);
163 printf("File %s is a %s while file %s is a %s\n",
164 _path1, "directory", _path2, "regular file");
167 printf("File %s is a %s while file %s is a %s\n",
168 _path1, "regular file", _path2, "directory");
171 printf("File %s is not a regular file or directory and was skipped\n",
175 printf("File %s is not a regular file or directory and was skipped\n",
184 static void fiddle_sum(int *sum, int t)
186 *sum = (int)(*sum * 127 + t);
189 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
191 static int readhash(FILE * f)
198 if (!(option_mask32 & (FLAG_b | FLAG_w))) {
199 for (i = 0; (t = getc(f)) != '\n'; i++) {
209 switch (t = getc(f)) {
218 if (space && !(option_mask32 & FLAG_w)) {
236 * There is a remote possibility that we end up with a zero sum.
237 * Zero is used as an EOF marker, so return 1 instead.
239 return (sum == 0 ? 1 : sum);
244 * Check to see if the given files differ.
245 * Returns 0 if they are the same, 1 if different, and -1 on error.
247 static int files_differ(FILE * f1, FILE * f2, int flags)
251 if ((flags & (D_EMPTY1 | D_EMPTY2)) || stb1.st_size != stb2.st_size
252 || (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT)
257 i = fread(bb_common_bufsiz1, 1, BUFSIZ/2, f1);
258 j = fread(bb_common_bufsiz1 + BUFSIZ/2, 1, BUFSIZ/2, f2);
262 return (ferror(f1) || ferror(f2));
263 if (memcmp(bb_common_bufsiz1,
264 bb_common_bufsiz1 + BUFSIZ/2, i) != 0)
270 static void prepare(int i, FILE * fd, off_t filesize)
278 sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;
282 p = xmalloc((sz + 3) * sizeof(struct line));
284 while ((h = readhash(fd))) {
287 p = xrealloc(p, (sz + 3) * sizeof(struct line));
296 static void prune(void)
300 for (pref = 0; pref < len[0] && pref < len[1] &&
301 file[0][pref + 1].value == file[1][pref + 1].value; pref++)
303 for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
304 file[0][len[0] - suff].value == file[1][len[1] - suff].value;
307 for (j = 0; j < 2; j++) {
308 sfile[j] = file[j] + pref;
309 slen[j] = len[j] - pref - suff;
310 for (i = 0; i <= slen[j]; i++)
311 sfile[j][i].serial = i;
316 static void equiv(struct line *a, int n, struct line *b, int m, int *c)
321 while (i <= n && j <= m) {
322 if (a[i].value < b[j].value)
324 else if (a[i].value == b[j].value)
335 while (b[j + 1].value == b[j].value) {
344 static int isqrt(int n)
356 } while ((x - y) > 1 || (x - y) < -1);
362 static int newcand(int x, int y, int pred)
366 if (clen == clistlen) {
367 clistlen = clistlen * 11 / 10;
368 clist = xrealloc(clist, clistlen * sizeof(struct cand));
378 static int search(int *c, int k, int y)
382 if (clist[c[k]].y < y) /* quick look for typical case */
402 static int stone(int *a, int n, int *b, int *c)
406 unsigned int numtries;
408 #if ENABLE_FEATURE_DIFF_MINIMAL
409 const unsigned int bound =
410 (option_mask32 & FLAG_d) ? UINT_MAX : MAX(256, isqrt(n));
412 const unsigned int bound = MAX(256, isqrt(n));
415 c[0] = newcand(0, 0, 0);
416 for (i = 1; i <= n; i++) {
425 if (y <= clist[oldc].y)
431 if (clist[c[l]].y <= y)
434 c[l] = newcand(i, y, oldc);
439 c[l] = newcand(i, y, oldc);
443 } while ((y = b[++j]) > 0 && numtries < bound);
449 static void unravel(int p)
454 for (i = 0; i <= len[0]; i++)
455 J[i] = i <= pref ? i : i > len[0] - suff ? i + len[1] - len[0] : 0;
456 for (q = clist + p; q->y != 0; q = clist + q->pred)
457 J[q->x + pref] = q->y + pref;
461 static void unsort(struct line *f, int l, int *b)
465 a = xmalloc((l + 1) * sizeof(int));
466 for (i = 1; i <= l; i++)
467 a[f[i].serial] = f[i].value;
468 for (i = 1; i <= l; i++)
474 static int skipline(FILE * f)
478 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
485 * Check does double duty:
486 * 1. ferret out any fortuitous correspondences due
487 * to confounding by hashing (which result in "jackpot")
488 * 2. collect random access indexes to the two files
490 static void check(FILE * f1, FILE * f2)
492 int i, j, jackpot, c, d;
498 ixold[0] = ixnew[0] = 0;
501 for (i = 1; i <= len[0]; i++) {
503 ixold[i] = ctold += skipline(f1);
507 ixnew[j] = ctnew += skipline(f2);
510 if ((option_mask32 & FLAG_b) || (option_mask32 & FLAG_w)
511 || (option_mask32 & FLAG_i)) {
516 * GNU diff ignores a missing newline
517 * in one file if bflag || wflag.
519 if (((option_mask32 & FLAG_b) || (option_mask32 & FLAG_w)) &&
520 ((c == EOF && d == '\n') || (c == '\n' && d == EOF))) {
525 if ((option_mask32 & FLAG_b) && isspace(c) && isspace(d)) {
530 } while (isspace(c = getc(f1)));
535 } while (isspace(d = getc(f2)));
536 } else if (option_mask32 & FLAG_w) {
537 while (isspace(c) && c != '\n') {
541 while (isspace(d) && d != '\n') {
549 if (c != '\n' && c != EOF)
550 ctold += skipline(f1);
551 if (d != '\n' && c != EOF)
552 ctnew += skipline(f2);
555 if (c == '\n' || c == EOF)
562 if ((c = getc(f1)) != (d = getc(f2))) {
564 if (c != '\n' && c != EOF)
565 ctold += skipline(f1);
566 if (d != '\n' && c != EOF)
567 ctnew += skipline(f2);
570 if (c == '\n' || c == EOF)
578 for (; j <= len[1]; j++)
579 ixnew[j] = ctnew += skipline(f2);
583 /* shellsort CACM #201 */
584 static void sort(struct line *a, int n)
586 struct line *ai, *aim, w;
591 for (j = 1; j <= n; j *= 2)
593 for (m /= 2; m != 0; m /= 2) {
595 for (j = 1; j <= k; j++) {
596 for (ai = &a[j]; ai > a; ai -= m) {
599 break; /* wraparound */
600 if (aim->value > ai[0].value ||
601 (aim->value == ai[0].value && aim->serial > ai[0].serial))
603 w.value = ai[0].value;
604 ai[0].value = aim->value;
605 aim->value = w.value;
606 w.serial = ai[0].serial;
607 ai[0].serial = aim->serial;
608 aim->serial = w.serial;
615 static void uni_range(int a, int b)
618 printf("%d,%d", a, b - a + 1);
626 static void fetch(long *f, int a, int b, FILE * lb, int ch)
628 int i, j, c, lastc, col, nc;
632 for (i = a; i <= b; i++) {
633 fseek(lb, f[i - 1], SEEK_SET);
634 nc = f[i] - f[i - 1];
637 if (option_mask32 & FLAG_T)
641 for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
642 if ((c = getc(lb)) == EOF) {
643 printf("\n\\ No newline at end of file\n");
646 if (c == '\t' && (option_mask32 & FLAG_t)) {
659 static int asciifile(FILE * f)
661 #if ENABLE_FEATURE_DIFF_BINARY
665 if ((option_mask32 & FLAG_a) || f == NULL)
668 #if ENABLE_FEATURE_DIFF_BINARY
670 cnt = fread(bb_common_bufsiz1, 1, BUFSIZ, f);
671 for (i = 0; i < cnt; i++) {
672 if (!isprint(bb_common_bufsiz1[i])
673 && !isspace(bb_common_bufsiz1[i])) {
682 /* dump accumulated "unified" diff changes */
683 static void dump_unified_vec(FILE * f1, FILE * f2)
685 struct context_vec *cvp = context_vec_start;
686 int lowa, upb, lowc, upd;
690 if (context_vec_start > context_vec_ptr)
694 lowa = MAX(1, cvp->a - context);
695 upb = MIN(len[0], context_vec_ptr->b + context);
696 lowc = MAX(1, cvp->c - context);
697 upd = MIN(len[1], context_vec_ptr->d + context);
700 uni_range(lowa, upb);
702 uni_range(lowc, upd);
706 * Output changes in "unified" diff format--the old and new lines
707 * are printed together.
709 for (; cvp <= context_vec_ptr; cvp++) {
716 * c: both new and old changes
717 * d: only changes in the old file
718 * a: only changes in the new file
720 if (a <= b && c <= d)
723 ch = (a <= b) ? 'd' : 'a';
724 if (ch == 'c' || ch == 'd') {
725 fetch(ixold, lowa, a - 1, f1, ' ');
726 fetch(ixold, a, b, f1, '-');
729 fetch(ixnew, lowc, c - 1, f2, ' ');
730 if (ch == 'c' || ch == 'a')
731 fetch(ixnew, c, d, f2, '+');
735 fetch(ixnew, d + 1, upd, f2, ' ');
737 context_vec_ptr = context_vec_start - 1;
741 static void print_header(const char *file1, const char *file2)
744 printf("--- %s\n", label1);
746 printf("--- %s\t%s", file1, ctime(&stb1.st_mtime));
748 printf("+++ %s\n", label2);
750 printf("+++ %s\t%s", file2, ctime(&stb2.st_mtime));
755 * Indicate that there is a difference between lines a and b of the from file
756 * to get to lines c to d of the to file. If a is greater than b then there
757 * are no lines in the from file involved and this means that there were
758 * lines appended (beginning at b). If c is greater than d then there are
759 * lines missing from the to file.
761 static void change(char *file1, FILE * f1, char *file2, FILE * f2, int a,
764 static size_t max_context = 64;
766 if ((a > b && c > d) || (option_mask32 & FLAG_q)) {
772 * Allocate change records as needed.
774 if (context_vec_ptr == context_vec_end - 1) {
775 ptrdiff_t offset = context_vec_ptr - context_vec_start;
778 context_vec_start = xrealloc(context_vec_start,
779 max_context * sizeof(struct context_vec));
780 context_vec_end = context_vec_start + max_context;
781 context_vec_ptr = context_vec_start + offset;
783 if (anychange == 0) {
785 * Print the context/unidiff header first time through.
787 print_header(file1, file2);
788 } else if (a > context_vec_ptr->b + (2 * context) + 1 &&
789 c > context_vec_ptr->d + (2 * context) + 1) {
791 * If this change is more than 'context' lines from the
792 * previous change, dump the record and reset it.
794 dump_unified_vec(f1, f2);
797 context_vec_ptr->a = a;
798 context_vec_ptr->b = b;
799 context_vec_ptr->c = c;
800 context_vec_ptr->d = d;
805 static void output(char *file1, FILE * f1, char *file2, FILE * f2)
807 /* Note that j0 and j1 can't be used as they are defined in math.h.
808 * This also allows the rather amusing variable 'j00'... */
809 int m, i0, i1, j00, j01;
815 J[m + 1] = len[1] + 1;
816 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
817 while (i0 <= m && J[i0] == J[i0 - 1] + 1)
821 while (i1 < m && J[i1 + 1] == 0)
825 change(file1, f1, file2, f2, i0, i1, j00, j01);
828 change(file1, f1, file2, f2, 1, 0, 1, len[1]);
830 if (anychange != 0 && !(option_mask32 & FLAG_q)) {
831 dump_unified_vec(f1, f2);
836 * The following code uses an algorithm due to Harold Stone,
837 * which finds a pair of longest identical subsequences in
840 * The major goal is to generate the match vector J.
841 * J[i] is the index of the line in file1 corresponding
842 * to line i file0. J[i] = 0 if there is no
843 * such line in file1.
845 * Lines are hashed so as to work in core. All potential
846 * matches are located by sorting the lines of each file
847 * on the hash (called ``value''). In particular, this
848 * collects the equivalence classes in file1 together.
849 * Subroutine equiv replaces the value of each line in
850 * file0 by the index of the first element of its
851 * matching equivalence in (the reordered) file1.
852 * To save space equiv squeezes file1 into a single
853 * array member in which the equivalence classes
854 * are simply concatenated, except that their first
855 * members are flagged by changing sign.
857 * Next the indices that point into member are unsorted into
858 * array class according to the original order of file0.
860 * The cleverness lies in routine stone. This marches
861 * through the lines of file0, developing a vector klist
862 * of "k-candidates". At step i a k-candidate is a matched
863 * pair of lines x,y (x in file0 y in file1) such that
864 * there is a common subsequence of length k
865 * between the first i lines of file0 and the first y
866 * lines of file1, but there is no such subsequence for
867 * any smaller y. x is the earliest possible mate to y
868 * that occurs in such a subsequence.
870 * Whenever any of the members of the equivalence class of
871 * lines in file1 matable to a line in file0 has serial number
872 * less than the y of some k-candidate, that k-candidate
873 * with the smallest such y is replaced. The new
874 * k-candidate is chained (via pred) to the current
875 * k-1 candidate so that the actual subsequence can
876 * be recovered. When a member has serial number greater
877 * that the y of all k-candidates, the klist is extended.
878 * At the end, the longest subsequence is pulled out
879 * and placed in the array J by unravel
881 * With J in hand, the matches there recorded are
882 * checked against reality to assure that no spurious
883 * matches have crept in due to hashing. If they have,
884 * they are broken, and "jackpot" is recorded--a harmless
885 * matter except that a true match for a spuriously
886 * mated line may now be unnecessarily reported as a change.
888 * Much of the complexity of the program comes simply
889 * from trying to minimize core utilization and
890 * maximize the range of doable problems by dynamically
891 * allocating what is needed and reusing what is not.
892 * The core requirements for problems larger than somewhat
893 * are (in words) 2*length(file0) + length(file1) +
894 * 3*(number of k-candidates installed), typically about
895 * 6n words for files of length n.
897 static unsigned diffreg(char * ofile1, char * ofile2, int flags)
899 char *file1 = ofile1;
900 char *file2 = ofile2;
901 FILE *f1 = stdin, *f2 = stdin;
906 context_vec_ptr = context_vec_start - 1;
908 if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
909 return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
913 if (LONE_DASH(file1) && LONE_DASH(file2))
916 if (flags & D_EMPTY1)
917 f1 = xfopen(bb_dev_null, "r");
918 else if (NOT_LONE_DASH(file1))
919 f1 = xfopen(file1, "r");
920 if (flags & D_EMPTY2)
921 f2 = xfopen(bb_dev_null, "r");
922 else if (NOT_LONE_DASH(file2))
923 f2 = xfopen(file2, "r");
925 /* We can't diff non-seekable stream - we use rewind(), fseek().
926 * This can be fixed (volunteers?).
927 * Meanwhile we should check it here by stat'ing input fds,
928 * but I am lazy and check that in main() instead.
929 * Check in main won't catch "diffing fifos buried in subdirectories"
930 * failure scenario - not very likely in real life... */
932 i = files_differ(f1, f2, flags);
935 else if (i != 1) { /* 1 == ok */
941 if (!asciifile(f1) || !asciifile(f2)) {
947 prepare(0, f1, stb1.st_size);
948 prepare(1, f2, stb2.st_size);
950 sort(sfile[0], slen[0]);
951 sort(sfile[1], slen[1]);
953 member = (int *) file[1];
954 equiv(sfile[0], slen[0], sfile[1], slen[1], member);
955 member = xrealloc(member, (slen[1] + 2) * sizeof(int));
957 class = (int *) file[0];
958 unsort(sfile[0], slen[0], class);
959 class = xrealloc(class, (slen[0] + 2) * sizeof(int));
961 klist = xmalloc((slen[0] + 2) * sizeof(int));
964 clist = xmalloc(clistlen * sizeof(struct cand));
965 i = stone(class, slen[0], member, klist);
969 J = xrealloc(J, (len[0] + 2) * sizeof(int));
974 ixold = xrealloc(ixold, (len[0] + 2) * sizeof(long));
975 ixnew = xrealloc(ixnew, (len[1] + 2) * sizeof(long));
977 output(file1, f1, file2, f2);
985 fclose_if_not_stdin(f1);
986 fclose_if_not_stdin(f2);
995 #if ENABLE_FEATURE_DIFF_DIR
996 static void do_diff(char *dir1, char *path1, char *dir2, char *path2)
998 int flags = D_HEADER;
1001 char *fullpath1 = concat_path_file(dir1, path1);
1002 char *fullpath2 = concat_path_file(dir2, path2);
1004 if (stat(fullpath1, &stb1) != 0) {
1006 memset(&stb1, 0, sizeof(stb1));
1007 if (ENABLE_FEATURE_CLEAN_UP)
1009 fullpath1 = concat_path_file(dir1, path2);
1011 if (stat(fullpath2, &stb2) != 0) {
1013 memset(&stb2, 0, sizeof(stb2));
1014 stb2.st_mode = stb1.st_mode;
1015 if (ENABLE_FEATURE_CLEAN_UP)
1017 fullpath2 = concat_path_file(dir2, path1);
1020 if (stb1.st_mode == 0)
1021 stb1.st_mode = stb2.st_mode;
1023 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1024 printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
1028 if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
1030 else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
1033 val = diffreg(fullpath1, fullpath2, flags);
1035 print_status(val, fullpath1, fullpath2, NULL);
1040 #if ENABLE_FEATURE_DIFF_DIR
1041 static int dir_strcmp(const void *p1, const void *p2)
1043 return strcmp(*(char *const *) p1, *(char *const *) p2);
1047 /* This function adds a filename to dl, the directory listing. */
1048 static int add_to_dirlist(const char *filename,
1049 struct stat ATTRIBUTE_UNUSED * sb, void *userdata,
1050 int depth ATTRIBUTE_UNUSED)
1052 /* +2: with space for eventual trailing NULL */
1053 dl = xrealloc(dl, (dl_count+2) * sizeof(dl[0]));
1054 dl[dl_count] = xstrdup(filename + (int)(ptrdiff_t)userdata);
1060 /* This returns a sorted directory listing. */
1061 static char **get_dir(char *path)
1066 /* If -r has been set, then the recursive_action function will be
1067 * used. Unfortunately, this outputs the root directory along with
1068 * the recursed paths, so use void *userdata to specify the string
1069 * length of the root directory - '(void*)(strlen(path)+)'.
1070 * add_to_dirlist then removes root dir prefix. */
1072 if (option_mask32 & FLAG_r) {
1073 recursive_action(path, TRUE, TRUE, FALSE, add_to_dirlist, NULL,
1074 (void*)(strlen(path)+1), 0);
1079 dp = warn_opendir(path);
1080 while ((ep = readdir(dp))) {
1081 if (!strcmp(ep->d_name, "..") || LONE_CHAR(ep->d_name, '.'))
1083 add_to_dirlist(ep->d_name, NULL, (void*)(int)0, 0);
1088 /* Sort dl alphabetically. */
1089 qsort(dl, dl_count, sizeof(char *), dir_strcmp);
1091 dl[dl_count] = NULL;
1096 static void diffdir(char *p1, char *p2)
1098 char **dirlist1, **dirlist2;
1102 /* Check for trailing slashes. */
1103 dp1 = last_char_is(p1, '/');
1106 dp2 = last_char_is(p2, '/');
1110 /* Get directory listings for p1 and p2. */
1112 dirlist1 = get_dir(p1);
1113 dirlist2 = get_dir(p2);
1115 /* If -S was set, find the starting point. */
1117 while (*dirlist1 != NULL && strcmp(*dirlist1, start) < 0)
1119 while (*dirlist2 != NULL && strcmp(*dirlist2, start) < 0)
1121 if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
1122 bb_error_msg(bb_msg_invalid_arg, "NULL", "-S");
1125 /* Now that both dirlist1 and dirlist2 contain sorted directory
1126 * listings, we can start to go through dirlist1. If both listings
1127 * contain the same file, then do a normal diff. Otherwise, behaviour
1128 * is determined by whether the -N flag is set. */
1129 while (*dirlist1 != NULL || *dirlist2 != NULL) {
1132 pos = dp1 == NULL ? 1 : dp2 == NULL ? -1 : strcmp(dp1, dp2);
1134 do_diff(p1, dp1, p2, dp2);
1137 } else if (pos < 0) {
1138 if (option_mask32 & FLAG_N)
1139 do_diff(p1, dp1, p2, NULL);
1141 print_only(p1, strlen(p1) + 1, dp1);
1144 if (option_mask32 & FLAG_N)
1145 do_diff(p1, NULL, p2, dp2);
1147 print_only(p2, strlen(p2) + 1, dp2);
1155 int diff_main(int argc, char **argv);
1156 int diff_main(int argc, char **argv)
1161 llist_t *L_arg = NULL;
1163 /* exactly 2 params; collect multiple -L <label> */
1164 opt_complementary = "=2:L::";
1165 getopt32(argc, argv, "abdiL:NqrsS:tTU:wu"
1166 "p" /* ignored (for compatibility) */,
1167 &L_arg, &start, &U_opt);
1171 if (label1 && label2)
1174 label1 = L_arg->data;
1175 else { /* then label2 is NULL */
1177 label1 = L_arg->data;
1179 /* we leak L_arg here... */
1180 L_arg = L_arg->link;
1182 if (option_mask32 & FLAG_U)
1183 context = xatoi_u(U_opt);
1186 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
1187 * driver routine. Both drivers use the contents of stb1 and stb2.
1192 if (LONE_DASH(f1)) {
1193 fstat(STDIN_FILENO, &stb1);
1197 if (LONE_DASH(f2)) {
1198 fstat(STDIN_FILENO, &stb2);
1202 if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
1203 bb_error_msg_and_die("can't compare - to a directory");
1204 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1205 #if ENABLE_FEATURE_DIFF_DIR
1208 bb_error_msg_and_die("directory comparison not supported");
1211 if (S_ISDIR(stb1.st_mode)) {
1212 f1 = concat_path_file(f1, f2);
1215 if (S_ISDIR(stb2.st_mode)) {
1216 f2 = concat_path_file(f2, f1);
1220 /* We can't diff e.g. stdin supplied by a pipe - we use rewind(), fseek().
1221 * This can be fixed (volunteers?) */
1222 if (!S_ISREG(stb1.st_mode) || !S_ISREG(stb2.st_mode))
1223 bb_error_msg_and_die("can't diff non-seekable stream");
1224 print_status(diffreg(f1, f2, 0), f1, f2, NULL);