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
19 /* NOINLINEs added to prevent gcc from merging too much into diffreg()
20 * (it bites more than it can (efficiently) chew). */
26 /* Print a header/footer between files */
27 /* D_HEADER = 1, - unused */
28 /* Treat file as empty (/dev/null) */
29 D_EMPTY1 = 2 * ENABLE_FEATURE_DIFF_DIR,
30 D_EMPTY2 = 4 * ENABLE_FEATURE_DIFF_DIR,
34 * Status values for print_status() and diffreg() return values
36 * D_SAME - files are the same
37 * D_DIFFER - files differ
38 * D_BINARY - binary files differ
39 * D_COMMON - subdirectory common to both dirs
40 * D_ONLY - file only exists in one dir
41 * D_ISDIR1 - path1 a dir, path2 a file
42 * D_ISDIR2 - path1 a file, path2 a dir
43 * D_ERROR - error occurred
44 * D_SKIPPED1 - skipped path1 as it is a special file
45 * D_SKIPPED2 - skipped path2 as it is a special file
48 #define D_DIFFER (1 << 0)
49 #define D_BINARY (1 << 1)
50 #define D_COMMON (1 << 2)
51 /*#define D_ONLY (1 << 3) - unused */
52 #define D_ISDIR1 (1 << 4)
53 #define D_ISDIR2 (1 << 5)
54 #define D_ERROR (1 << 6)
55 #define D_SKIPPED1 (1 << 7)
56 #define D_SKIPPED2 (1 << 8)
58 /* Command line options */
59 #define FLAG_a (1 << 0)
60 #define FLAG_b (1 << 1)
61 #define FLAG_d (1 << 2)
62 #define FLAG_i (1 << 3)
63 #define FLAG_L (1 << 4)
64 #define FLAG_N (1 << 5)
65 #define FLAG_q (1 << 6)
66 #define FLAG_r (1 << 7)
67 #define FLAG_s (1 << 8)
68 #define FLAG_S (1 << 9)
69 #define FLAG_t (1 << 10)
70 #define FLAG_T (1 << 11)
71 #define FLAG_U (1 << 12)
72 #define FLAG_w (1 << 13)
87 * The following struct is used to record change information
88 * doing a "context" or "unified" diff. (see routine "change" to
89 * understand the highly mnemonic field names)
92 int a; /* start line in old file */
93 int b; /* end line in old file */
94 int c; /* start line in new file */
95 int d; /* end line in new file */
99 #define g_read_buf bb_common_bufsiz1
103 smallint exit_status;
105 size_t max_context; /* size of context_vec_start */
106 IF_FEATURE_DIFF_DIR(int dl_count;)
107 IF_FEATURE_DIFF_DIR(char **dl;)
111 int *J; /* will be overlaid on class */
113 int pref, suff; /* length of prefix and suffix */
116 int clistlen; /* the length of clist */
117 struct cand *clist; /* merely a free storage pot for candidates */
118 long *ixnew; /* will be overlaid on nfile[1] */
119 long *ixold; /* will be overlaid on klist */
120 struct line *nfile[2];
121 struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
122 struct context_vec *context_vec_start;
123 struct context_vec *context_vec_end;
124 struct context_vec *context_vec_ptr;
125 char *tempname1, *tempname2;
126 struct stat stb1, stb2;
128 #define G (*ptr_to_globals)
129 #define anychange (G.anychange )
130 #define exit_status (G.exit_status )
131 #define opt_U_context (G.opt_U_context )
132 #define max_context (G.max_context )
133 #define dl_count (G.dl_count )
135 #define opt_S_start (G.opt_S_start )
136 #define label1 (G.label1 )
137 #define label2 (G.label2 )
139 #define clen (G.clen )
140 #define pref (G.pref )
141 #define suff (G.suff )
142 #define nlen (G.nlen )
143 #define slen (G.slen )
144 #define clistlen (G.clistlen )
145 #define clist (G.clist )
146 #define ixnew (G.ixnew )
147 #define ixold (G.ixold )
148 #define nfile (G.nfile )
149 #define sfile (G.sfile )
150 #define context_vec_start (G.context_vec_start )
151 #define context_vec_end (G.context_vec_end )
152 #define context_vec_ptr (G.context_vec_ptr )
153 #define stb1 (G.stb1 )
154 #define stb2 (G.stb2 )
155 #define tempname1 (G.tempname1 )
156 #define tempname2 (G.tempname2 )
157 #define INIT_G() do { \
158 SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
164 #if ENABLE_FEATURE_DIFF_DIR
165 static void print_only(const char *path, const char *entry)
167 printf("Only in %s: %s\n", path, entry);
172 static void print_status(int val, char *_path1, char *_path2)
174 /*const char *const _entry = entry ? entry : "";*/
175 /*char *const _path1 = entry ? concat_path_file(path1, _entry) : path1;*/
176 /*char *const _path2 = entry ? concat_path_file(path2, _entry) : path2;*/
180 print_only(path1, entry);
184 printf("Common subdirectories: %s and %s\n", _path1, _path2);
187 printf("Binary files %s and %s differ\n", _path1, _path2);
190 if (option_mask32 & FLAG_q)
191 printf("Files %s and %s differ\n", _path1, _path2);
194 if (option_mask32 & FLAG_s)
195 printf("Files %s and %s are identical\n", _path1, _path2);
198 printf("File %s is a %s while file %s is a %s\n",
199 _path1, "directory", _path2, "regular file");
202 printf("File %s is a %s while file %s is a %s\n",
203 _path1, "regular file", _path2, "directory");
206 printf("File %s is not a regular file or directory and was skipped\n",
210 printf("File %s is not a regular file or directory and was skipped\n",
223 /* Read line, return its nonzero hash. Return 0 if EOF.
225 * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
227 static ALWAYS_INLINE int fiddle_sum(int sum, int t)
229 return sum * 127 + t;
231 static int readhash(FILE *fp)
239 if (!(option_mask32 & (FLAG_b | FLAG_w))) {
240 while ((t = getc(fp)) != '\n') {
246 sum = fiddle_sum(sum, t);
251 switch (t = getc(fp)) {
260 if (space && !(option_mask32 & FLAG_w)) {
264 sum = fiddle_sum(sum, t);
278 * There is a remote possibility that we end up with a zero sum.
279 * Zero is used as an EOF marker, so return 1 instead.
281 return (sum == 0 ? 1 : sum);
285 /* Our diff implementation is using seek.
286 * When we meet non-seekable file, we must make a temp copy.
288 static char *make_temp(FILE *f, struct stat *sb)
293 if (S_ISREG(sb->st_mode) || S_ISBLK(sb->st_mode))
295 name = xstrdup("/tmp/difXXXXXX");
298 bb_perror_msg_and_die("mkstemp");
299 if (bb_copyfd_eof(fileno(f), fd) < 0) {
302 xfunc_die(); /* error message is printed by bb_copyfd_eof */
306 if (freopen(name, "r+", f) == NULL) {
307 bb_perror_msg("freopen");
315 * Check to see if the given files differ.
316 * Returns 0 if they are the same, 1 if different, and -1 on error.
318 static NOINLINE int files_differ(FILE *f1, FILE *f2)
322 /* Prevent making copies for "/dev/null" (too common) */
323 /* Deal with input from pipes etc */
324 tempname1 = make_temp(f1, &stb1);
325 tempname2 = make_temp(f2, &stb2);
326 if (stb1.st_size != stb2.st_size) {
330 i = fread(g_read_buf, 1, COMMON_BUFSIZE/2, f1);
331 j = fread(g_read_buf + COMMON_BUFSIZE/2, 1, COMMON_BUFSIZE/2, f2);
335 return (ferror(f1) || ferror(f2)) ? -1 : 0;
336 if (memcmp(g_read_buf,
337 g_read_buf + COMMON_BUFSIZE/2, i) != 0)
343 static void prepare(int i, FILE *fp /*, off_t filesize*/)
351 /*sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;*/
355 p = xmalloc((sz + 3) * sizeof(p[0]));
357 while ((h = readhash(fp)) != 0) { /* while not EOF */
360 p = xrealloc(p, (sz + 3) * sizeof(p[0]));
369 static void prune(void)
373 for (pref = 0; pref < nlen[0] && pref < nlen[1] &&
374 nfile[0][pref + 1].value == nfile[1][pref + 1].value; pref++)
376 for (suff = 0; suff < nlen[0] - pref && suff < nlen[1] - pref &&
377 nfile[0][nlen[0] - suff].value == nfile[1][nlen[1] - suff].value;
380 for (j = 0; j < 2; j++) {
381 sfile[j] = nfile[j] + pref;
382 slen[j] = nlen[j] - pref - suff;
383 for (i = 0; i <= slen[j]; i++)
384 sfile[j][i].serial = i;
389 static void equiv(struct line *a, int n, struct line *b, int m, int *c)
394 while (i <= n && j <= m) {
395 if (a[i].value < b[j].value)
397 else if (a[i].value == b[j].value)
408 while (b[j + 1].value == b[j].value) {
417 static int isqrt(int n)
429 } while ((x - y) > 1 || (x - y) < -1);
435 static int newcand(int x, int y, int pred)
439 if (clen == clistlen) {
440 clistlen = clistlen * 11 / 10;
441 clist = xrealloc(clist, clistlen * sizeof(struct cand));
451 static int search(int *c, int k, int y)
455 if (clist[c[k]].y < y) /* quick look for typical case */
475 static int stone(int *a, int n, int *b, int *c)
479 unsigned int numtries;
480 #if ENABLE_FEATURE_DIFF_MINIMAL
481 const unsigned int bound =
482 (option_mask32 & FLAG_d) ? UINT_MAX : MAX(256, isqrt(n));
484 const unsigned int bound = MAX(256, isqrt(n));
488 c[0] = newcand(0, 0, 0);
489 for (i = 1; i <= n; i++) {
498 if (y <= clist[oldc].y)
504 if (clist[c[l]].y <= y)
507 c[l] = newcand(i, y, oldc);
512 c[l] = newcand(i, y, oldc);
516 } while ((y = b[++j]) > 0 && numtries < bound);
522 static void unravel(int p)
527 for (i = 0; i <= nlen[0]; i++)
528 J[i] = i <= pref ? i : i > nlen[0] - suff ? i + nlen[1] - nlen[0] : 0;
529 for (q = clist + p; q->y != 0; q = clist + q->pred)
530 J[q->x + pref] = q->y + pref;
534 static void unsort(struct line *f, int l, int *b)
538 a = xmalloc((l + 1) * sizeof(int));
539 for (i = 1; i <= l; i++)
540 a[f[i].serial] = f[i].value;
541 for (i = 1; i <= l; i++)
547 static int skipline(FILE *f)
551 for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
558 * Check does double duty:
559 * 1. ferret out any fortuitous correspondences due
560 * to confounding by hashing (which result in "jackpot")
561 * 2. collect random access indexes to the two files
563 static NOINLINE void check(FILE *f1, FILE *f2)
565 int i, j, jackpot, c, d;
571 ixold[0] = ixnew[0] = 0;
574 for (i = 1; i <= nlen[0]; i++) {
576 ixold[i] = ctold += skipline(f1);
580 ixnew[j] = ctnew += skipline(f2);
583 if (option_mask32 & (FLAG_b | FLAG_w | FLAG_i)) {
588 * GNU diff ignores a missing newline
589 * in one file if bflag || wflag.
591 if ((option_mask32 & (FLAG_b | FLAG_w))
592 && ((c == EOF && d == '\n') || (c == '\n' && d == EOF))
598 if ((option_mask32 & FLAG_b) && isspace(c) && isspace(d)) {
604 } while (isspace(c));
610 } while (isspace(d));
611 } else if (option_mask32 & FLAG_w) {
612 while (isspace(c) && c != '\n') {
616 while (isspace(d) && d != '\n') {
624 if (c != '\n' && c != EOF)
625 ctold += skipline(f1);
626 if (d != '\n' && c != EOF)
627 ctnew += skipline(f2);
630 if (c == '\n' || c == EOF)
641 if (c != '\n' && c != EOF)
642 ctold += skipline(f1);
643 /* was buggy? "if (d != '\n' && c != EOF)" */
644 if (d != '\n' && d != EOF)
645 ctnew += skipline(f2);
648 if (c == '\n' || c == EOF)
656 for (; j <= nlen[1]; j++)
657 ixnew[j] = ctnew += skipline(f2);
661 /* shellsort CACM #201 */
662 static void sort(struct line *a, int n)
664 struct line *ai, *aim, w;
669 for (j = 1; j <= n; j *= 2)
671 for (m /= 2; m != 0; m /= 2) {
673 for (j = 1; j <= k; j++) {
674 for (ai = &a[j]; ai > a; ai -= m) {
677 break; /* wraparound */
678 if (aim->value > ai[0].value
679 || (aim->value == ai[0].value && aim->serial > ai[0].serial)
683 w.value = ai[0].value;
684 ai[0].value = aim->value;
685 aim->value = w.value;
686 w.serial = ai[0].serial;
687 ai[0].serial = aim->serial;
688 aim->serial = w.serial;
695 static void uni_range(int a, int b)
698 printf("%d,%d", a, b - a + 1);
706 static void fetch(long *f, int a, int b, FILE *lb, int ch)
708 int i, j, c, lastc, col, nc;
712 for (i = a; i <= b; i++) {
713 fseek(lb, f[i - 1], SEEK_SET);
714 nc = f[i] - f[i - 1];
717 if (option_mask32 & FLAG_T)
721 for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
724 printf("\n\\ No newline at end of file\n");
727 if (c == '\t' && (option_mask32 & FLAG_t)) {
740 #if ENABLE_FEATURE_DIFF_BINARY
741 static int asciifile(FILE *f)
745 if (option_mask32 & FLAG_a)
748 cnt = fread(g_read_buf, 1, COMMON_BUFSIZE, f);
749 for (i = 0; i < cnt; i++) {
750 if (!isprint(g_read_buf[i])
751 && !isspace(g_read_buf[i])
759 #define asciifile(f) 1
763 /* dump accumulated "unified" diff changes */
764 static void dump_unified_vec(FILE *f1, FILE *f2)
766 struct context_vec *cvp = context_vec_start;
767 int lowa, upb, lowc, upd;
771 if (context_vec_start > context_vec_ptr)
775 lowa = MAX(1, cvp->a - opt_U_context);
776 upb = MIN(nlen[0], context_vec_ptr->b + opt_U_context);
777 lowc = MAX(1, cvp->c - opt_U_context);
778 upd = MIN(nlen[1], context_vec_ptr->d + opt_U_context);
781 uni_range(lowa, upb);
783 uni_range(lowc, upd);
787 * Output changes in "unified" diff format--the old and new lines
788 * are printed together.
790 for (; cvp <= context_vec_ptr; cvp++) {
797 * c: both new and old changes
798 * d: only changes in the old file
799 * a: only changes in the new file
801 if (a <= b && c <= d)
804 ch = (a <= b) ? 'd' : 'a';
809 fetch(ixold, lowa, a - 1, f1, ' ');
810 fetch(ixold, a, b, f1, '-');
811 fetch(ixnew, c, d, f2, '+');
814 fetch(ixold, lowa, a - 1, f1, ' ');
815 fetch(ixold, a, b, f1, '-');
818 fetch(ixnew, lowc, c - 1, f2, ' ');
819 fetch(ixnew, c, d, f2, '+');
823 if (ch == 'c' || ch == 'd') {
824 fetch(ixold, lowa, a - 1, f1, ' ');
825 fetch(ixold, a, b, f1, '-');
828 fetch(ixnew, lowc, c - 1, f2, ' ');
829 if (ch == 'c' || ch == 'a')
830 fetch(ixnew, c, d, f2, '+');
835 fetch(ixnew, d + 1, upd, f2, ' ');
837 context_vec_ptr = context_vec_start - 1;
841 static void print_header(const char *file1, const char *file2)
844 printf("--- %s\n", label1);
846 printf("--- %s\t%s", file1, ctime(&stb1.st_mtime));
848 printf("+++ %s\n", label2);
850 printf("+++ %s\t%s", file2, ctime(&stb2.st_mtime));
855 * Indicate that there is a difference between lines a and b of the from file
856 * to get to lines c to d of the to file. If a is greater than b then there
857 * are no lines in the from file involved and this means that there were
858 * lines appended (beginning at b). If c is greater than d then there are
859 * lines missing from the to file.
861 static void change(const char *file1, FILE *f1, const char *file2, FILE *f2,
862 int a, int b, int c, int d)
864 if ((a > b && c > d) || (option_mask32 & FLAG_q)) {
870 * Allocate change records as needed.
872 if (context_vec_ptr == context_vec_end - 1) {
873 ptrdiff_t offset = context_vec_ptr - context_vec_start;
876 context_vec_start = xrealloc(context_vec_start,
877 max_context * sizeof(struct context_vec));
878 context_vec_end = context_vec_start + max_context;
879 context_vec_ptr = context_vec_start + offset;
881 if (anychange == 0) {
883 * Print the context/unidiff header first time through.
885 print_header(file1, file2);
886 } else if (a > context_vec_ptr->b + (2 * opt_U_context) + 1
887 && c > context_vec_ptr->d + (2 * opt_U_context) + 1
890 * If this change is more than 'context' lines from the
891 * previous change, dump the record and reset it.
893 // dump_unified_vec() seeks!
894 dump_unified_vec(f1, f2);
897 context_vec_ptr->a = a;
898 context_vec_ptr->b = b;
899 context_vec_ptr->c = c;
900 context_vec_ptr->d = d;
905 static void output(const char *file1, FILE *f1, const char *file2, FILE *f2)
907 /* Note that j0 and j1 can't be used as they are defined in math.h.
908 * This also allows the rather amusing variable 'j00'... */
909 int m, i0, i1, j00, j01;
915 J[m + 1] = nlen[1] + 1;
916 for (i0 = 1; i0 <= m; i0 = i1 + 1) {
917 while (i0 <= m && J[i0] == J[i0 - 1] + 1)
921 while (i1 < m && J[i1 + 1] == 0)
926 change(file1, f1, file2, f2, i0, i1, j00, j01);
930 change(file1, f1, file2, f2, 1, 0, 1, nlen[1]);
932 if (anychange != 0 && !(option_mask32 & FLAG_q)) {
933 // dump_unified_vec() seeks!
934 dump_unified_vec(f1, f2);
939 * The following code uses an algorithm due to Harold Stone,
940 * which finds a pair of longest identical subsequences in
943 * The major goal is to generate the match vector J.
944 * J[i] is the index of the line in file1 corresponding
945 * to line i in file0. J[i] = 0 if there is no
946 * such line in file1.
948 * Lines are hashed so as to work in core. All potential
949 * matches are located by sorting the lines of each file
950 * on the hash (called "value"). In particular, this
951 * collects the equivalence classes in file1 together.
952 * Subroutine equiv replaces the value of each line in
953 * file0 by the index of the first element of its
954 * matching equivalence in (the reordered) file1.
955 * To save space equiv squeezes file1 into a single
956 * array member in which the equivalence classes
957 * are simply concatenated, except that their first
958 * members are flagged by changing sign.
960 * Next the indices that point into member are unsorted into
961 * array class according to the original order of file0.
963 * The cleverness lies in routine stone. This marches
964 * through the lines of file0, developing a vector klist
965 * of "k-candidates". At step i a k-candidate is a matched
966 * pair of lines x,y (x in file0, y in file1) such that
967 * there is a common subsequence of length k
968 * between the first i lines of file0 and the first y
969 * lines of file1, but there is no such subsequence for
970 * any smaller y. x is the earliest possible mate to y
971 * that occurs in such a subsequence.
973 * Whenever any of the members of the equivalence class of
974 * lines in file1 matable to a line in file0 has serial number
975 * less than the y of some k-candidate, that k-candidate
976 * with the smallest such y is replaced. The new
977 * k-candidate is chained (via pred) to the current
978 * k-1 candidate so that the actual subsequence can
979 * be recovered. When a member has serial number greater
980 * that the y of all k-candidates, the klist is extended.
981 * At the end, the longest subsequence is pulled out
982 * and placed in the array J by unravel
984 * With J in hand, the matches there recorded are
985 * checked against reality to assure that no spurious
986 * matches have crept in due to hashing. If they have,
987 * they are broken, and "jackpot" is recorded--a harmless
988 * matter except that a true match for a spuriously
989 * mated line may now be unnecessarily reported as a change.
991 * Much of the complexity of the program comes simply
992 * from trying to minimize core utilization and
993 * maximize the range of doable problems by dynamically
994 * allocating what is needed and reusing what is not.
995 * The core requirements for problems larger than somewhat
996 * are (in words) 2*length(file0) + length(file1) +
997 * 3*(number of k-candidates installed), typically about
998 * 6n words for files of length n.
1000 /* NB: files can be not REGular. The only sure thing that they
1001 * are not both DIRectories. */
1002 static unsigned diffreg(const char *file1, const char *file2, int flags)
1004 int *member; /* will be overlaid on nfile[1] */
1005 int *class; /* will be overlaid on nfile[0] */
1006 int *klist; /* will be overlaid on nfile[0] after class */
1013 context_vec_ptr = context_vec_start - 1;
1014 tempname1 = tempname2 = NULL;
1016 /* Is any of them a directory? Then it's simple */
1017 if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
1018 return (S_ISDIR(stb1.st_mode) ? D_ISDIR1 : D_ISDIR2);
1020 /* None of them are directories */
1023 if (flags & D_EMPTY1)
1024 /* can't be stdin, but xfopen_stdin() is smaller code */
1025 file1 = bb_dev_null;
1026 f1 = xfopen_stdin(file1);
1027 if (flags & D_EMPTY2)
1028 file2 = bb_dev_null;
1029 f2 = xfopen_stdin(file2);
1031 /* NB: if D_EMPTY1/2 is set, other file is always a regular file,
1032 * not pipe/fifo/chardev/etc - D_EMPTY is used by "diff -r" only,
1033 * and it never diffs non-ordinary files in subdirs. */
1034 if (!(flags & (D_EMPTY1 | D_EMPTY2))) {
1035 /* Quick check whether they are different */
1036 /* NB: copies non-REG files to tempfiles and fills tempname1/2 */
1037 i = files_differ(f1, f2);
1038 if (i != 1) { /* not different? */
1039 if (i != 0) /* error? */
1045 if (!asciifile(f1) || !asciifile(f2)) {
1052 prepare(0, f1 /*, stb1.st_size*/);
1053 prepare(1, f2 /*, stb2.st_size*/);
1055 sort(sfile[0], slen[0]);
1056 sort(sfile[1], slen[1]);
1058 member = (int *) nfile[1];
1059 equiv(sfile[0], slen[0], sfile[1], slen[1], member);
1060 //TODO: xrealloc_vector?
1061 member = xrealloc(member, (slen[1] + 2) * sizeof(int));
1063 class = (int *) nfile[0];
1064 unsort(sfile[0], slen[0], class);
1065 class = xrealloc(class, (slen[0] + 2) * sizeof(int));
1067 klist = xmalloc((slen[0] + 2) * sizeof(int));
1070 clist = xmalloc(clistlen * sizeof(struct cand));
1071 i = stone(class, slen[0], member, klist);
1075 J = xrealloc(J, (nlen[0] + 2) * sizeof(int));
1080 ixold = xrealloc(ixold, (nlen[0] + 2) * sizeof(long));
1081 ixnew = xrealloc(ixnew, (nlen[1] + 2) * sizeof(long));
1085 output(file1, f1, file2, f2);
1093 fclose_if_not_stdin(f1);
1094 fclose_if_not_stdin(f2);
1107 #if ENABLE_FEATURE_DIFF_DIR
1108 static void do_diff(char *dir1, char *path1, char *dir2, char *path2)
1110 int flags = 0; /*D_HEADER;*/
1112 char *fullpath1 = NULL; /* if -N */
1113 char *fullpath2 = NULL;
1116 fullpath1 = concat_path_file(dir1, path1);
1118 fullpath2 = concat_path_file(dir2, path2);
1120 if (!fullpath1 || stat(fullpath1, &stb1) != 0) {
1122 memset(&stb1, 0, sizeof(stb1));
1125 fullpath1 = concat_path_file(dir1, path2);
1128 if (!fullpath2 || stat(fullpath2, &stb2) != 0) {
1130 memset(&stb2, 0, sizeof(stb2));
1131 stb2.st_mode = stb1.st_mode;
1134 fullpath2 = concat_path_file(dir2, path1);
1138 if (stb1.st_mode == 0)
1139 stb1.st_mode = stb2.st_mode;
1141 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1142 printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
1146 if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
1148 else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
1151 /* Both files are either REGular or DIRectories */
1152 val = diffreg(fullpath1, fullpath2, flags);
1155 print_status(val, fullpath1, fullpath2 /*, NULL*/);
1163 #if ENABLE_FEATURE_DIFF_DIR
1164 /* This function adds a filename to dl, the directory listing. */
1165 static int FAST_FUNC add_to_dirlist(const char *filename,
1166 struct stat *sb UNUSED_PARAM,
1168 int depth UNUSED_PARAM)
1170 dl = xrealloc_vector(dl, 5, dl_count);
1171 dl[dl_count] = xstrdup(filename + (int)(ptrdiff_t)userdata);
1177 /* This returns a sorted directory listing. */
1178 static char **get_recursive_dirlist(char *path)
1181 dl = xzalloc(sizeof(dl[0]));
1183 /* We need to trim root directory prefix.
1184 * Using void *userdata to specify its length,
1185 * add_to_dirlist will remove it. */
1186 if (option_mask32 & FLAG_r) {
1187 recursive_action(path, ACTION_RECURSE|ACTION_FOLLOWLINKS,
1188 add_to_dirlist, /* file_action */
1189 NULL, /* dir_action */
1190 (void*)(ptrdiff_t)(strlen(path) + 1),
1196 dp = warn_opendir(path);
1197 while ((ep = readdir(dp))) {
1198 if (!strcmp(ep->d_name, "..") || LONE_CHAR(ep->d_name, '.'))
1200 add_to_dirlist(ep->d_name, NULL, (void*)(int)0, 0);
1205 /* Sort dl alphabetically. */
1206 qsort_string_vector(dl, dl_count);
1208 dl[dl_count] = NULL;
1213 static void diffdir(char *p1, char *p2)
1215 char **dirlist1, **dirlist2;
1219 /* Check for trailing slashes. */
1220 dp1 = last_char_is(p1, '/');
1223 dp2 = last_char_is(p2, '/');
1227 /* Get directory listings for p1 and p2. */
1228 dirlist1 = get_recursive_dirlist(p1);
1229 dirlist2 = get_recursive_dirlist(p2);
1231 /* If -S was set, find the starting point. */
1233 while (*dirlist1 != NULL && strcmp(*dirlist1, opt_S_start) < 0)
1235 while (*dirlist2 != NULL && strcmp(*dirlist2, opt_S_start) < 0)
1237 if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
1238 bb_error_msg(bb_msg_invalid_arg, "NULL", "-S");
1241 /* Now that both dirlist1 and dirlist2 contain sorted directory
1242 * listings, we can start to go through dirlist1. If both listings
1243 * contain the same file, then do a normal diff. Otherwise, behaviour
1244 * is determined by whether the -N flag is set. */
1245 while (*dirlist1 != NULL || *dirlist2 != NULL) {
1248 pos = dp1 == NULL ? 1 : (dp2 == NULL ? -1 : strcmp(dp1, dp2));
1250 do_diff(p1, dp1, p2, dp2);
1253 } else if (pos < 0) {
1254 if (option_mask32 & FLAG_N)
1255 do_diff(p1, dp1, p2, NULL);
1257 print_only(p1, dp1);
1260 if (option_mask32 & FLAG_N)
1261 do_diff(p1, NULL, p2, dp2);
1263 print_only(p2, dp2);
1271 int diff_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1272 int diff_main(int argc UNUSED_PARAM, char **argv)
1276 llist_t *L_arg = NULL;
1280 /* exactly 2 params; collect multiple -L <label>; -U N */
1281 opt_complementary = "=2:L::U+";
1282 getopt32(argv, "abdiL:NqrsS:tTU:wu"
1283 "p" /* ignored (for compatibility) */,
1284 &L_arg, &opt_S_start, &opt_U_context);
1288 if (label1 && label2)
1290 if (label1) /* then label2 is NULL */
1292 label1 = llist_pop(&L_arg);
1296 * Do sanity checks, fill in stb1 and stb2 and call the appropriate
1297 * driver routine. Both drivers use the contents of stb1 and stb2.
1301 if (LONE_DASH(f1)) {
1302 fstat(STDIN_FILENO, &stb1);
1306 if (LONE_DASH(f2)) {
1307 fstat(STDIN_FILENO, &stb2);
1312 if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
1313 bb_error_msg_and_die("can't compare stdin to a directory");
1315 if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
1316 #if ENABLE_FEATURE_DIFF_DIR
1320 bb_error_msg_and_die("no support for directory comparison");
1324 if (S_ISDIR(stb1.st_mode)) { /* "diff dir file" */
1325 /* NB: "diff dir dir2/dir3/file" must become
1326 * "diff dir/file dir2/dir3/file" */
1327 char *slash = strrchr(f2, '/');
1328 f1 = concat_path_file(f1, slash ? slash + 1 : f2);
1331 if (S_ISDIR(stb2.st_mode)) {
1332 char *slash = strrchr(f1, '/');
1333 f2 = concat_path_file(f2, slash ? slash + 1 : f1);
1337 /* diffreg can get non-regular files here,
1338 * they are not both DIRestories */
1339 print_status((gotstdin > 1 ? D_SAME : diffreg(f1, f2, 0)),