* Mini diff implementation for busybox, adapted from OpenBSD diff.
*
* Copyright (C) 2006 by Robert Sullivan <cogito.ergo.cogito@hotmail.com>
- *
+ *
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
/*
* Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
*
- * Permission to
+ * Permission to
* use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
* D_SKIPPED2 - skipped path2 as it is a special file
*/
-#define D_SAME 0
-#define D_DIFFER 1
+#define D_SAME 0
+#define D_DIFFER (1<<0)
#define D_BINARY (1<<1)
#define D_COMMON (1<<2)
#define D_ONLY (1<<3)
/* Command line options */
static unsigned long cmd_flags;
-#define FLAG_a 1
+#define FLAG_a (1<<0)
#define FLAG_b (1<<1)
#define FLAG_d (1<<2)
#define FLAG_i (1<<3)
static struct context_vec *context_vec_end;
static struct context_vec *context_vec_ptr;
-static void output(char *, FILE *, char *, FILE *);
-static void check(char *, FILE *, char *, FILE *);
-static void uni_range(int, int);
-static void dump_unified_vec(FILE *, FILE *);
-static void prepare(int, FILE *, off_t);
-static void prune(void);
-static void equiv(struct line *, int, struct line *, int, int *);
-static void unravel(int);
-static void unsort(struct line *, int, int *);
-static void change(char *, FILE *, char *, FILE *, int, int, int, int);
-static void sort(struct line *, int);
-static void print_header(const char *, const char *);
-static int asciifile(FILE *);
-static int fetch(long *, int, int, FILE *, int, int);
-static int newcand(int, int, int);
-static int search(int *, int, int);
-static int skipline(FILE *);
-static int stone(int *, int, int *, int *);
-static int readhash(FILE *);
-static int files_differ(FILE *, FILE *, int);
-
-static int diffreg(char *, char *, int);
-static void print_only(const char *, size_t, const char *);
-static void print_status(int, char *, char *, char *);
-
-#ifdef CONFIG_FEATURE_DIFF_DIR
-static int dir_strcmp(const void *p1, const void *p2) {
- return strcmp(*(char * const *)p1, *(char * const *)p2);
-}
-
-/* This function adds a filename to dl, the directory listing. */
-
-static int add_to_dirlist (const char *filename, struct stat *statbuf, void *userdata) {
- dl_count++;
- dl = xrealloc(dl, dl_count * sizeof(char *));
- dl[dl_count - 1] = bb_xstrdup(filename);
- if (cmd_flags & FLAG_r) {
- int *pp = (int *) userdata;
- int path_len = *pp + 1;
- dl[dl_count - 1] = &(dl[dl_count - 1])[path_len];
- }
- return TRUE;
-}
-
-/* This returns a sorted directory listing. */
-static char **get_dir(char *path) {
-
- int i;
-
- /* Reset dl_count - there's no need to free dl as bb_xrealloc does
- * the job nicely. */
- dl_count = 0;
-
- /* If -r has been set, then the recursive_action function will be
- * used. Unfortunately, this outputs the root directory along with
- * the recursed paths, so use void *userdata to specify the string
- * length of the root directory. It can then be removed in
- * add_to_dirlist. */
-
- int path_len = strlen(path);
- void *userdata = &path_len;
-
- /* Now fill dl with a listing. */
- if (cmd_flags & FLAG_r)
- recursive_action(path, TRUE, TRUE, FALSE, add_to_dirlist, NULL, userdata);
- else {
- DIR *dp;
- struct dirent *ep;
- if ((dp = opendir(path)) == NULL)
- bb_error_msg("Error reading directory");
- while ((ep = readdir(dp))) {
- if ((!strcmp(ep->d_name, "..")) || (!strcmp(ep->d_name, ".")))
- continue;
- add_to_dirlist(ep->d_name, NULL, NULL);
- }
- closedir(dp);
- }
-
- /* Sort dl alphabetically. */
- qsort(dl, dl_count, sizeof(char *), dir_strcmp);
-
- /* Copy dl so that we can return it. */
- char **retval = xmalloc(dl_count * sizeof(char *));
- for (i = 0; i < dl_count; i++)
- retval[i] = bb_xstrdup(dl[i]);
-
- return retval;
-}
-
-static void do_diff (char *dir1, char *path1, char *dir2, char *path2) {
-
- int flags = D_HEADER;
- int val;
-
- char *fullpath1 = bb_xasprintf("%s/%s", dir1, path1);
- char *fullpath2 = bb_xasprintf("%s/%s", dir2, path2);
-
- if (stat(fullpath1, &stb1) != 0) {
- flags |= D_EMPTY1;
- memset(&stb1, 0, sizeof(stb1));
- fullpath1 = bb_xasprintf("%s/%s", dir1, path2);
- }
- if (stat(fullpath2, &stb2) != 0) {
- flags |= D_EMPTY2;
- memset(&stb2, 0, sizeof(stb2));
- stb2.st_mode = stb1.st_mode;
- fullpath2 = bb_xasprintf("%s/%s", dir2, path1);
- }
-
- if (stb1.st_mode == 0)
- stb1.st_mode = stb2.st_mode;
-
- if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
- printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
- return;
- }
-
- if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
- val = D_SKIPPED1;
- else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
- val = D_SKIPPED2;
- else
- val = diffreg(fullpath1, fullpath2, flags);
-
- print_status(val, fullpath1, fullpath2, NULL);
-}
-
-static void diffdir (char *p1, char *p2) {
-
- char **dirlist1, **dirlist2;
- char *dp1, *dp2;
- int dirlist1_count, dirlist2_count;
- int pos;
-
- /* Check for trailing slashes. */
-
- if (p1[strlen(p1) - 1] == '/')
- p1[strlen(p1) - 1] = '\0';
- if (p2[strlen(p2) - 1] == '/')
- p2[strlen(p2) - 1] = '\0';
-
- /* Get directory listings for p1 and p2. */
-
- dirlist1 = get_dir(p1);
- dirlist1_count = dl_count;
- dirlist1[dirlist1_count] = NULL;
- dirlist2 = get_dir(p2);
- dirlist2_count = dl_count;
- dirlist2[dirlist2_count] = NULL;
-
- /* If -S was set, find the starting point. */
- if (start) {
- while (*dirlist1 != NULL && strcmp(*dirlist1, start) < 0)
- dirlist1++;
- while (*dirlist2 != NULL && strcmp(*dirlist2, start) < 0)
- dirlist2++;
- if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
- bb_error_msg("Invalid argument to -S");
- }
-
- /* Now that both dirlist1 and dirlist2 contain sorted directory
- * listings, we can start to go through dirlist1. If both listings
- * contain the same file, then do a normal diff. Otherwise, behaviour
- * is determined by whether the -N flag is set. */
- while (*dirlist1 != NULL || *dirlist2 != NULL) {
- dp1 = *dirlist1;
- dp2 = *dirlist2;
- pos = dp1 == NULL ? 1 : dp2 == NULL ? -1 : strcmp(dp1, dp2);
- if (pos == 0) {
- do_diff(p1, dp1, p2, dp2);
- dirlist1++;
- dirlist2++;
- }
- else if (pos < 0) {
- if (cmd_flags & FLAG_N)
- do_diff(p1, dp1, p2, NULL);
- else
- print_only(p1, strlen(p1) + 1, dp1);
- dirlist1++;
- }
- else {
- if (cmd_flags & FLAG_N)
- do_diff(p1, NULL, p2, dp2);
- else
- print_only(p2, strlen(p2) + 1, dp2);
- dirlist2++;
- }
- }
-}
-#endif
-
-static void
-print_only(const char *path, size_t dirlen, const char *entry)
+static void print_only(const char *path, size_t dirlen, const char *entry)
{
if (dirlen > 1)
dirlen--;
printf("Only in %.*s: %s\n", (int)dirlen, path, entry);
}
-static void
-print_status(int val, char *path1, char *path2, char *entry)
+static void print_status(int val, char *path1, char *path2, char *entry)
{
switch (val) {
case D_ONLY:
}
/*
- * The following code uses an algorithm due to Harold Stone,
- * which finds a pair of longest identical subsequences in
- * the two files.
- *
- * The major goal is to generate the match vector J.
- * J[i] is the index of the line in file1 corresponding
- * to line i file0. J[i] = 0 if there is no
- * such line in file1.
- *
- * Lines are hashed so as to work in core. All potential
- * matches are located by sorting the lines of each file
- * on the hash (called ``value''). In particular, this
- * collects the equivalence classes in file1 together.
- * Subroutine equiv replaces the value of each line in
- * file0 by the index of the first element of its
- * matching equivalence in (the reordered) file1.
- * To save space equiv squeezes file1 into a single
- * array member in which the equivalence classes
- * are simply concatenated, except that their first
- * members are flagged by changing sign.
- *
- * Next the indices that point into member are unsorted into
- * array class according to the original order of file0.
- *
- * The cleverness lies in routine stone. This marches
- * through the lines of file0, developing a vector klist
- * of "k-candidates". At step i a k-candidate is a matched
- * pair of lines x,y (x in file0 y in file1) such that
- * there is a common subsequence of length k
- * between the first i lines of file0 and the first y
- * lines of file1, but there is no such subsequence for
- * any smaller y. x is the earliest possible mate to y
- * that occurs in such a subsequence.
- *
- * Whenever any of the members of the equivalence class of
- * lines in file1 matable to a line in file0 has serial number
- * less than the y of some k-candidate, that k-candidate
- * with the smallest such y is replaced. The new
- * k-candidate is chained (via pred) to the current
- * k-1 candidate so that the actual subsequence can
- * be recovered. When a member has serial number greater
- * that the y of all k-candidates, the klist is extended.
- * At the end, the longest subsequence is pulled out
- * and placed in the array J by unravel
- *
- * With J in hand, the matches there recorded are
- * checked against reality to assure that no spurious
- * matches have crept in due to hashing. If they have,
- * they are broken, and "jackpot" is recorded--a harmless
- * matter except that a true match for a spuriously
- * mated line may now be unnecessarily reported as a change.
- *
- * Much of the complexity of the program comes simply
- * from trying to minimize core utilization and
- * maximize the range of doable problems by dynamically
- * allocating what is needed and reusing what is not.
- * The core requirements for problems larger than somewhat
- * are (in words) 2*length(file0) + length(file1) +
- * 3*(number of k-candidates installed), typically about
- * 6n words for files of length n.
+ * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
*/
-
-static int diffreg(char *ofile1, char *ofile2, int flags)
+static int readhash(FILE *f)
{
- char *file1 = ofile1;
- char *file2 = ofile2;
- FILE *f1 = NULL;
- FILE *f2 = NULL;
- int rval = D_SAME;
- int i;
-
- anychange = 0;
- context_vec_ptr = context_vec_start - 1;
-
- if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
- return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
- if (strcmp(file1, "-") == 0 && strcmp(file2, "-") == 0)
- goto closem;
-
- if (flags & D_EMPTY1)
- f1 = bb_xfopen(_PATH_DEVNULL, "r");
- else {
- if (strcmp(file1, "-") == 0)
- f1 = stdin;
- else
- f1 = bb_xfopen(file1, "r");
- }
+ int i, t, space;
+ int sum;
- if (flags & D_EMPTY2)
- f2 = bb_xfopen(_PATH_DEVNULL, "r");
- else {
- if (strcmp(file2, "-") == 0)
- f2 = stdin;
+ sum = 1;
+ space = 0;
+ if (!(cmd_flags & FLAG_b) && !(cmd_flags & FLAG_w)) {
+ if (FLAG_i)
+ for (i = 0; (t = getc(f)) != '\n'; i++) {
+ if (t == EOF) {
+ if (i == 0)
+ return (0);
+ break;
+ }
+ sum = sum * 127 + t;
+ }
else
- f2 = bb_xfopen(file2, "r");
- }
-
- switch (files_differ(f1, f2, flags)) {
- case 0:
- goto closem;
- case 1:
- break;
- default:
- /* error */
- status |= 2;
- goto closem;
- }
-
- if (!asciifile(f1) || !asciifile(f2)) {
- rval = D_BINARY;
- status |= 1;
- goto closem;
+ for (i = 0; (t = getc(f)) != '\n'; i++) {
+ if (t == EOF) {
+ if (i == 0)
+ return (0);
+ break;
+ }
+ sum = sum * 127 + t;
+ }
+ } else {
+ for (i = 0;;) {
+ switch (t = getc(f)) {
+ case '\t':
+ case '\r':
+ case '\v':
+ case '\f':
+ case ' ':
+ space++;
+ continue;
+ default:
+ if (space && !(cmd_flags & FLAG_w)) {
+ i++;
+ space = 0;
+ }
+ sum = sum * 127 + t;
+ i++;
+ continue;
+ case EOF:
+ if (i == 0)
+ return (0);
+ /* FALLTHROUGH */
+ case '\n':
+ break;
+ }
+ break;
+ }
}
+ /*
+ * There is a remote possibility that we end up with a zero sum.
+ * Zero is used as an EOF marker, so return 1 instead.
+ */
+ return (sum == 0 ? 1 : sum);
+}
- prepare(0, f1, stb1.st_size);
- prepare(1, f2, stb2.st_size);
- prune();
- sort(sfile[0], slen[0]);
- sort(sfile[1], slen[1]);
-
- member = (int *)file[1];
- equiv(sfile[0], slen[0], sfile[1], slen[1], member);
- member = xrealloc(member, (slen[1] + 2) * sizeof(int));
-
- class = (int *)file[0];
- unsort(sfile[0], slen[0], class);
- class = xrealloc(class, (slen[0] + 2) * sizeof(int));
-
- klist = xmalloc((slen[0] + 2) * sizeof(int));
- clen = 0;
- clistlen = 100;
- clist = xmalloc(clistlen * sizeof(struct cand));
- i = stone(class, slen[0], member, klist);
- free(member);
- free(class);
-
- J = xrealloc(J, (len[0] + 2) * sizeof(int));
- unravel(klist[i]);
- free(clist);
- free(klist);
-
- ixold = xrealloc(ixold, (len[0] + 2) * sizeof(long));
- ixnew = xrealloc(ixnew, (len[1] + 2) * sizeof(long));
- check(file1, f1, file2, f2);
- output(file1, f1, file2, f2);
-closem:
- if (anychange) {
- status |= 1;
- if (rval == D_SAME)
- rval = D_DIFFER;
- }
- if (f1 != NULL)
- fclose(f1);
- if (f2 != NULL)
- fclose(f2);
- if (file1 != ofile1)
- free(file1);
- if (file2 != ofile2)
- free(file2);
- return (rval);
-}
/*
* Check to see if the given files differ.
* Returns 0 if they are the same, 1 if different, and -1 on error.
*/
-static int
-files_differ(FILE *f1, FILE *f2, int flags)
+static int files_differ(FILE *f1, FILE *f2, int flags)
{
char buf1[BUFSIZ], buf2[BUFSIZ];
size_t i, j;
}
}
-static void
-prepare(int i, FILE *fd, off_t filesize)
+static void prepare(int i, FILE *fd, off_t filesize)
{
struct line *p;
int j, h;
file[i] = p;
}
-static void
-prune(void)
+static void prune(void)
{
int i, j;
}
}
-static void
-equiv(struct line *a, int n, struct line *b, int m, int *c)
+static void equiv(struct line *a, int n, struct line *b, int m, int *c)
{
int i, j;
static int isqrt(int n) {
int y, x = 1;
- if (n == 0) return(0);
-
+ if (n == 0) return(0);
+
do {
y = x;
x = n / x;
return (x);
}
-static int
-stone(int *a, int n, int *b, int *c)
+
+static int newcand(int x, int y, int pred)
+{
+ struct cand *q;
+
+ if (clen == clistlen) {
+ clistlen = clistlen * 11 / 10;
+ clist = xrealloc(clist, clistlen * sizeof(struct cand));
+ }
+ q = clist + clen;
+ q->x = x;
+ q->y = y;
+ q->pred = pred;
+ return (clen++);
+}
+
+
+static int search(int *c, int k, int y)
+{
+ int i, j, l, t;
+
+ if (clist[c[k]].y < y) /* quick look for typical case */
+ return (k + 1);
+ i = 0;
+ j = k + 1;
+ while (1) {
+ l = i + j;
+ if ((l >>= 1) <= i)
+ break;
+ t = clist[c[l]].y;
+ if (t > y)
+ j = l;
+ else if (t < y)
+ i = l;
+ else
+ return (l);
+ }
+ return (l + 1);
+}
+
+
+static int stone(int *a, int n, int *b, int *c)
{
int i, k, y, j, l;
int oldc, tc, oldl;
return (k);
}
-static int
-newcand(int x, int y, int pred)
+static void unravel(int p)
{
struct cand *q;
+ int i;
- if (clen == clistlen) {
- clistlen = clistlen * 11 / 10;
- clist = xrealloc(clist, clistlen * sizeof(struct cand));
- }
- q = clist + clen;
- q->x = x;
- q->y = y;
- q->pred = pred;
- return (clen++);
+ for (i = 0; i <= len[0]; i++)
+ J[i] = i <= pref ? i :
+ i > len[0] - suff ? i + len[1] - len[0] : 0;
+ for (q = clist + p; q->y != 0; q = clist + q->pred)
+ J[q->x + pref] = q->y + pref;
}
-static int
-search(int *c, int k, int y)
+
+static void unsort(struct line *f, int l, int *b)
{
- int i, j, l, t;
+ int *a, i;
- if (clist[c[k]].y < y) /* quick look for typical case */
- return (k + 1);
- i = 0;
- j = k + 1;
- while (1) {
- l = i + j;
- if ((l >>= 1) <= i)
- break;
- t = clist[c[l]].y;
- if (t > y)
- j = l;
- else if (t < y)
- i = l;
- else
- return (l);
- }
- return (l + 1);
+ a = xmalloc((l + 1) * sizeof(int));
+ for (i = 1; i <= l; i++)
+ a[f[i].serial] = f[i].value;
+ for (i = 1; i <= l; i++)
+ b[i] = a[i];
+ free(a);
}
-static void
-unravel(int p)
+static int skipline(FILE *f)
{
- struct cand *q;
- int i;
+ int i, c;
- for (i = 0; i <= len[0]; i++)
- J[i] = i <= pref ? i :
- i > len[0] - suff ? i + len[1] - len[0] : 0;
- for (q = clist + p; q->y != 0; q = clist + q->pred)
- J[q->x + pref] = q->y + pref;
+ for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
+ continue;
+ return (i);
}
+
/*
* Check does double duty:
* 1. ferret out any fortuitous correspondences due
* to confounding by hashing (which result in "jackpot")
* 2. collect random access indexes to the two files
*/
-static void
-check(char *file1, FILE *f1, char *file2, FILE *f2)
+static void check(char *file1, FILE *f1, char *file2, FILE *f2)
{
int i, j, jackpot, c, d;
long ctold, ctnew;
}
/* shellsort CACM #201 */
-static void
-sort(struct line *a, int n)
+static void sort(struct line *a, int n)
{
struct line *ai, *aim, w;
int j, m = 0, k;
}
}
-static void
-unsort(struct line *f, int l, int *b)
-{
- int *a, i;
-
- a = xmalloc((l + 1) * sizeof(int));
- for (i = 1; i <= l; i++)
- a[f[i].serial] = f[i].value;
- for (i = 1; i <= l; i++)
- b[i] = a[i];
- free(a);
-}
-static int
-skipline(FILE *f)
+static void uni_range(int a, int b)
{
- int i, c;
-
- for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
- continue;
- return (i);
+ if (a < b)
+ printf("%d,%d", a, b - a + 1);
+ else if (a == b)
+ printf("%d", b);
+ else
+ printf("%d,0", b);
}
-static void
-output(char *file1, FILE *f1, char *file2, FILE *f2)
+static int fetch(long *f, int a, int b, FILE *lb, int ch, int oldfile)
{
- int m, i0, i1, j0, j1;
-
- rewind(f1);
- rewind(f2);
- m = len[0];
- J[0] = 0;
- J[m + 1] = len[1] + 1;
- for (i0 = 1; i0 <= m; i0 = i1 + 1) {
- while (i0 <= m && J[i0] == J[i0 - 1] + 1)
- i0++;
- j0 = J[i0 - 1] + 1;
- i1 = i0 - 1;
- while (i1 < m && J[i1 + 1] == 0)
- i1++;
- j1 = J[i1 + 1] - 1;
- J[i1] = j1;
- change(file1, f1, file2, f2, i0, i1, j0, j1);
- }
- if (m == 0) {
- change(file1, f1, file2, f2, 1, 0, 1, len[1]);
- }
- if (anychange != 0) {
- dump_unified_vec(f1, f2);
- }
-}
-
-static void uni_range(int a, int b)
-{
- if (a < b)
- printf("%d,%d", a, b - a + 1);
- else if (a == b)
- printf("%d", b);
- else
- printf("%d,0", b);
-}
-
-/*
- * Indicate that there is a difference between lines a and b of the from file
- * to get to lines c to d of the to file. If a is greater then b then there
- * are no lines in the from file involved and this means that there were
- * lines appended (beginning at b). If c is greater than d then there are
- * lines missing from the to file.
- */
-static void
-change(char *file1, FILE *f1, char *file2, FILE *f2, int a, int b, int c, int d)
-{
- static size_t max_context = 64;
-
- if (a > b && c > d) return;
- if (cmd_flags & FLAG_q) return;
-
- /*
- * Allocate change records as needed.
- */
- if (context_vec_ptr == context_vec_end - 1) {
- ptrdiff_t offset = context_vec_ptr - context_vec_start;
- max_context <<= 1;
- context_vec_start = xrealloc(context_vec_start,
- max_context * sizeof(struct context_vec));
- context_vec_end = context_vec_start + max_context;
- context_vec_ptr = context_vec_start + offset;
- }
- if (anychange == 0) {
- /*
- * Print the context/unidiff header first time through.
- */
- print_header(file1, file2);
- anychange = 1;
- } else if (a > context_vec_ptr->b + (2 * context) + 1 &&
- c > context_vec_ptr->d + (2 * context) + 1) {
- /*
- * If this change is more than 'context' lines from the
- * previous change, dump the record and reset it.
- */
- dump_unified_vec(f1, f2);
- }
- context_vec_ptr++;
- context_vec_ptr->a = a;
- context_vec_ptr->b = b;
- context_vec_ptr->c = c;
- context_vec_ptr->d = d;
- return;
-
-}
-
-static int
-fetch(long *f, int a, int b, FILE *lb, int ch, int oldfile)
-{
- int i, j, c, lastc, col, nc;
+ int i, j, c, lastc, col, nc;
if (a > b)
return (0);
return (0);
}
-/*
- * Hash function taken from Robert Sedgewick, Algorithms in C, 3d ed., p 578.
- */
-static int
-readhash(FILE *f)
-{
- int i, t, space;
- int sum;
-
- sum = 1;
- space = 0;
- if (!(cmd_flags & FLAG_b) && !(cmd_flags & FLAG_w)) {
- if (FLAG_i)
- for (i = 0; (t = getc(f)) != '\n'; i++) {
- if (t == EOF) {
- if (i == 0)
- return (0);
- break;
- }
- sum = sum * 127 + t;
- }
- else
- for (i = 0; (t = getc(f)) != '\n'; i++) {
- if (t == EOF) {
- if (i == 0)
- return (0);
- break;
- }
- sum = sum * 127 + t;
- }
- } else {
- for (i = 0;;) {
- switch (t = getc(f)) {
- case '\t':
- case '\r':
- case '\v':
- case '\f':
- case ' ':
- space++;
- continue;
- default:
- if (space && !(cmd_flags & FLAG_w)) {
- i++;
- space = 0;
- }
- sum = sum * 127 + t;
- i++;
- continue;
- case EOF:
- if (i == 0)
- return (0);
- /* FALLTHROUGH */
- case '\n':
- break;
- }
- break;
- }
- }
- /*
- * There is a remote possibility that we end up with a zero sum.
- * Zero is used as an EOF marker, so return 1 instead.
- */
- return (sum == 0 ? 1 : sum);
-}
-
-static int
-asciifile(FILE *f)
+static int asciifile(FILE *f)
{
- if ((cmd_flags & FLAG_a) || f == NULL)
- return (1);
+ if ((cmd_flags & FLAG_a) || f == NULL)
+ return (1);
#ifdef CONFIG_FEATURE_DIFF_BINARY
unsigned char buf[BUFSIZ];
int i, cnt;
-
+
rewind(f);
cnt = fread(buf, 1, sizeof(buf), f);
for (i = 0; i < cnt; i++)
}
/* dump accumulated "unified" diff changes */
-static void
-dump_unified_vec(FILE *f1, FILE *f2)
+static void dump_unified_vec(FILE *f1, FILE *f2)
{
struct context_vec *cvp = context_vec_start;
int lowa, upb, lowc, upd;
context_vec_ptr = context_vec_start - 1;
}
-static void
-print_header(const char *file1, const char *file2)
+
+static void print_header(const char *file1, const char *file2)
{
if (label[0] != NULL)
printf("%s %s\n", "---",
file2, ctime(&stb2.st_mtime));
}
+
+
+/*
+ * Indicate that there is a difference between lines a and b of the from file
+ * to get to lines c to d of the to file. If a is greater then b then there
+ * are no lines in the from file involved and this means that there were
+ * lines appended (beginning at b). If c is greater than d then there are
+ * lines missing from the to file.
+ */
+static void change(char *file1, FILE *f1, char *file2, FILE *f2, int a, int b, int c, int d)
+{
+ static size_t max_context = 64;
+
+ if (a > b && c > d) return;
+ if (cmd_flags & FLAG_q) return;
+
+ /*
+ * Allocate change records as needed.
+ */
+ if (context_vec_ptr == context_vec_end - 1) {
+ ptrdiff_t offset = context_vec_ptr - context_vec_start;
+ max_context <<= 1;
+ context_vec_start = xrealloc(context_vec_start,
+ max_context * sizeof(struct context_vec));
+ context_vec_end = context_vec_start + max_context;
+ context_vec_ptr = context_vec_start + offset;
+ }
+ if (anychange == 0) {
+ /*
+ * Print the context/unidiff header first time through.
+ */
+ print_header(file1, file2);
+ anychange = 1;
+ } else if (a > context_vec_ptr->b + (2 * context) + 1 &&
+ c > context_vec_ptr->d + (2 * context) + 1) {
+ /*
+ * If this change is more than 'context' lines from the
+ * previous change, dump the record and reset it.
+ */
+ dump_unified_vec(f1, f2);
+ }
+ context_vec_ptr++;
+ context_vec_ptr->a = a;
+ context_vec_ptr->b = b;
+ context_vec_ptr->c = c;
+ context_vec_ptr->d = d;
+ return;
+
+}
+
+
+static void output(char *file1, FILE *f1, char *file2, FILE *f2)
+{
+ int m, i0, i1, j0, j1;
+
+ rewind(f1);
+ rewind(f2);
+ m = len[0];
+ J[0] = 0;
+ J[m + 1] = len[1] + 1;
+ for (i0 = 1; i0 <= m; i0 = i1 + 1) {
+ while (i0 <= m && J[i0] == J[i0 - 1] + 1)
+ i0++;
+ j0 = J[i0 - 1] + 1;
+ i1 = i0 - 1;
+ while (i1 < m && J[i1 + 1] == 0)
+ i1++;
+ j1 = J[i1 + 1] - 1;
+ J[i1] = j1;
+ change(file1, f1, file2, f2, i0, i1, j0, j1);
+ }
+ if (m == 0) {
+ change(file1, f1, file2, f2, 1, 0, 1, len[1]);
+ }
+ if (anychange != 0) {
+ dump_unified_vec(f1, f2);
+ }
+}
+
+/*
+ * The following code uses an algorithm due to Harold Stone,
+ * which finds a pair of longest identical subsequences in
+ * the two files.
+ *
+ * The major goal is to generate the match vector J.
+ * J[i] is the index of the line in file1 corresponding
+ * to line i file0. J[i] = 0 if there is no
+ * such line in file1.
+ *
+ * Lines are hashed so as to work in core. All potential
+ * matches are located by sorting the lines of each file
+ * on the hash (called ``value''). In particular, this
+ * collects the equivalence classes in file1 together.
+ * Subroutine equiv replaces the value of each line in
+ * file0 by the index of the first element of its
+ * matching equivalence in (the reordered) file1.
+ * To save space equiv squeezes file1 into a single
+ * array member in which the equivalence classes
+ * are simply concatenated, except that their first
+ * members are flagged by changing sign.
+ *
+ * Next the indices that point into member are unsorted into
+ * array class according to the original order of file0.
+ *
+ * The cleverness lies in routine stone. This marches
+ * through the lines of file0, developing a vector klist
+ * of "k-candidates". At step i a k-candidate is a matched
+ * pair of lines x,y (x in file0 y in file1) such that
+ * there is a common subsequence of length k
+ * between the first i lines of file0 and the first y
+ * lines of file1, but there is no such subsequence for
+ * any smaller y. x is the earliest possible mate to y
+ * that occurs in such a subsequence.
+ *
+ * Whenever any of the members of the equivalence class of
+ * lines in file1 matable to a line in file0 has serial number
+ * less than the y of some k-candidate, that k-candidate
+ * with the smallest such y is replaced. The new
+ * k-candidate is chained (via pred) to the current
+ * k-1 candidate so that the actual subsequence can
+ * be recovered. When a member has serial number greater
+ * that the y of all k-candidates, the klist is extended.
+ * At the end, the longest subsequence is pulled out
+ * and placed in the array J by unravel
+ *
+ * With J in hand, the matches there recorded are
+ * checked against reality to assure that no spurious
+ * matches have crept in due to hashing. If they have,
+ * they are broken, and "jackpot" is recorded--a harmless
+ * matter except that a true match for a spuriously
+ * mated line may now be unnecessarily reported as a change.
+ *
+ * Much of the complexity of the program comes simply
+ * from trying to minimize core utilization and
+ * maximize the range of doable problems by dynamically
+ * allocating what is needed and reusing what is not.
+ * The core requirements for problems larger than somewhat
+ * are (in words) 2*length(file0) + length(file1) +
+ * 3*(number of k-candidates installed), typically about
+ * 6n words for files of length n.
+ */
+
+static int diffreg(char *ofile1, char *ofile2, int flags)
+{
+ char *file1 = ofile1;
+ char *file2 = ofile2;
+ FILE *f1 = NULL;
+ FILE *f2 = NULL;
+ int rval = D_SAME;
+ int i;
+
+ anychange = 0;
+ context_vec_ptr = context_vec_start - 1;
+
+ if (S_ISDIR(stb1.st_mode) != S_ISDIR(stb2.st_mode))
+ return (S_ISDIR(stb1.st_mode) ? D_MISMATCH1 : D_MISMATCH2);
+ if (strcmp(file1, "-") == 0 && strcmp(file2, "-") == 0)
+ goto closem;
+
+ if (flags & D_EMPTY1)
+ f1 = bb_xfopen(_PATH_DEVNULL, "r");
+ else {
+ if (strcmp(file1, "-") == 0)
+ f1 = stdin;
+ else
+ f1 = bb_xfopen(file1, "r");
+ }
+
+ if (flags & D_EMPTY2)
+ f2 = bb_xfopen(_PATH_DEVNULL, "r");
+ else {
+ if (strcmp(file2, "-") == 0)
+ f2 = stdin;
+ else
+ f2 = bb_xfopen(file2, "r");
+ }
+
+ switch (files_differ(f1, f2, flags)) {
+ case 0:
+ goto closem;
+ case 1:
+ break;
+ default:
+ /* error */
+ status |= 2;
+ goto closem;
+ }
+
+ if (!asciifile(f1) || !asciifile(f2)) {
+ rval = D_BINARY;
+ status |= 1;
+ goto closem;
+ }
+
+ prepare(0, f1, stb1.st_size);
+ prepare(1, f2, stb2.st_size);
+ prune();
+ sort(sfile[0], slen[0]);
+ sort(sfile[1], slen[1]);
+
+ member = (int *)file[1];
+ equiv(sfile[0], slen[0], sfile[1], slen[1], member);
+ member = xrealloc(member, (slen[1] + 2) * sizeof(int));
+
+ class = (int *)file[0];
+ unsort(sfile[0], slen[0], class);
+ class = xrealloc(class, (slen[0] + 2) * sizeof(int));
+
+ klist = xmalloc((slen[0] + 2) * sizeof(int));
+ clen = 0;
+ clistlen = 100;
+ clist = xmalloc(clistlen * sizeof(struct cand));
+ i = stone(class, slen[0], member, klist);
+ free(member);
+ free(class);
+
+ J = xrealloc(J, (len[0] + 2) * sizeof(int));
+ unravel(klist[i]);
+ free(clist);
+ free(klist);
+
+ ixold = xrealloc(ixold, (len[0] + 2) * sizeof(long));
+ ixnew = xrealloc(ixnew, (len[1] + 2) * sizeof(long));
+ check(file1, f1, file2, f2);
+ output(file1, f1, file2, f2);
+
+closem:
+ if (anychange) {
+ status |= 1;
+ if (rval == D_SAME)
+ rval = D_DIFFER;
+ }
+ if (f1 != NULL)
+ fclose(f1);
+ if (f2 != NULL)
+ fclose(f2);
+ if (file1 != ofile1)
+ free(file1);
+ if (file2 != ofile2)
+ free(file2);
+ return (rval);
+}
+
+#if ENABLE_FEATURE_DIFF_DIR
+static void do_diff (char *dir1, char *path1, char *dir2, char *path2) {
+
+ int flags = D_HEADER;
+ int val;
+
+ char *fullpath1 = bb_xasprintf("%s/%s", dir1, path1);
+ char *fullpath2 = bb_xasprintf("%s/%s", dir2, path2);
+
+ if (stat(fullpath1, &stb1) != 0) {
+ flags |= D_EMPTY1;
+ memset(&stb1, 0, sizeof(stb1));
+ fullpath1 = bb_xasprintf("%s/%s", dir1, path2);
+ }
+ if (stat(fullpath2, &stb2) != 0) {
+ flags |= D_EMPTY2;
+ memset(&stb2, 0, sizeof(stb2));
+ stb2.st_mode = stb1.st_mode;
+ fullpath2 = bb_xasprintf("%s/%s", dir2, path1);
+ }
+
+ if (stb1.st_mode == 0)
+ stb1.st_mode = stb2.st_mode;
+
+ if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
+ printf("Common subdirectories: %s and %s\n", fullpath1, fullpath2);
+ return;
+ }
+
+ if (!S_ISREG(stb1.st_mode) && !S_ISDIR(stb1.st_mode))
+ val = D_SKIPPED1;
+ else if (!S_ISREG(stb2.st_mode) && !S_ISDIR(stb2.st_mode))
+ val = D_SKIPPED2;
+ else
+ val = diffreg(fullpath1, fullpath2, flags);
+
+ print_status(val, fullpath1, fullpath2, NULL);
+}
+#endif
+
+#ifdef CONFIG_FEATURE_DIFF_DIR
+static int dir_strcmp(const void *p1, const void *p2) {
+ return strcmp(*(char * const *)p1, *(char * const *)p2);
+}
+
+/* This function adds a filename to dl, the directory listing. */
+
+static int add_to_dirlist (const char *filename, struct stat *statbuf, void *userdata) {
+ dl_count++;
+ dl = xrealloc(dl, dl_count * sizeof(char *));
+ dl[dl_count - 1] = bb_xstrdup(filename);
+ if (cmd_flags & FLAG_r) {
+ int *pp = (int *) userdata;
+ int path_len = *pp + 1;
+ dl[dl_count - 1] = &(dl[dl_count - 1])[path_len];
+ }
+ return TRUE;
+}
+
+/* This returns a sorted directory listing. */
+static char **get_dir(char *path) {
+
+ int i;
+
+ /* Reset dl_count - there's no need to free dl as bb_xrealloc does
+ * the job nicely. */
+ dl_count = 0;
+
+ /* If -r has been set, then the recursive_action function will be
+ * used. Unfortunately, this outputs the root directory along with
+ * the recursed paths, so use void *userdata to specify the string
+ * length of the root directory. It can then be removed in
+ * add_to_dirlist. */
+
+ int path_len = strlen(path);
+ void *userdata = &path_len;
+
+ /* Now fill dl with a listing. */
+ if (cmd_flags & FLAG_r)
+ recursive_action(path, TRUE, TRUE, FALSE, add_to_dirlist, NULL, userdata);
+ else {
+ DIR *dp;
+ struct dirent *ep;
+ if ((dp = opendir(path)) == NULL)
+ bb_error_msg("Error reading directory");
+ while ((ep = readdir(dp))) {
+ if ((!strcmp(ep->d_name, "..")) || (!strcmp(ep->d_name, ".")))
+ continue;
+ add_to_dirlist(ep->d_name, NULL, NULL);
+ }
+ closedir(dp);
+ }
+
+ /* Sort dl alphabetically. */
+ qsort(dl, dl_count, sizeof(char *), dir_strcmp);
+
+ /* Copy dl so that we can return it. */
+ char **retval = xmalloc(dl_count * sizeof(char *));
+ for (i = 0; i < dl_count; i++)
+ retval[i] = bb_xstrdup(dl[i]);
+
+ return retval;
+}
+
+static void diffdir (char *p1, char *p2) {
+
+ char **dirlist1, **dirlist2;
+ char *dp1, *dp2;
+ int dirlist1_count, dirlist2_count;
+ int pos;
+
+ /* Check for trailing slashes. */
+
+ if (p1[strlen(p1) - 1] == '/')
+ p1[strlen(p1) - 1] = '\0';
+ if (p2[strlen(p2) - 1] == '/')
+ p2[strlen(p2) - 1] = '\0';
+
+ /* Get directory listings for p1 and p2. */
+
+ dirlist1 = get_dir(p1);
+ dirlist1_count = dl_count;
+ dirlist1[dirlist1_count] = NULL;
+ dirlist2 = get_dir(p2);
+ dirlist2_count = dl_count;
+ dirlist2[dirlist2_count] = NULL;
+
+ /* If -S was set, find the starting point. */
+ if (start) {
+ while (*dirlist1 != NULL && strcmp(*dirlist1, start) < 0)
+ dirlist1++;
+ while (*dirlist2 != NULL && strcmp(*dirlist2, start) < 0)
+ dirlist2++;
+ if ((*dirlist1 == NULL) || (*dirlist2 == NULL))
+ bb_error_msg("Invalid argument to -S");
+ }
+
+ /* Now that both dirlist1 and dirlist2 contain sorted directory
+ * listings, we can start to go through dirlist1. If both listings
+ * contain the same file, then do a normal diff. Otherwise, behaviour
+ * is determined by whether the -N flag is set. */
+ while (*dirlist1 != NULL || *dirlist2 != NULL) {
+ dp1 = *dirlist1;
+ dp2 = *dirlist2;
+ pos = dp1 == NULL ? 1 : dp2 == NULL ? -1 : strcmp(dp1, dp2);
+ if (pos == 0) {
+ do_diff(p1, dp1, p2, dp2);
+ dirlist1++;
+ dirlist2++;
+ }
+ else if (pos < 0) {
+ if (cmd_flags & FLAG_N)
+ do_diff(p1, dp1, p2, NULL);
+ else
+ print_only(p1, strlen(p1) + 1, dp1);
+ dirlist1++;
+ }
+ else {
+ if (cmd_flags & FLAG_N)
+ do_diff(p1, NULL, p2, dp2);
+ else
+ print_only(p2, strlen(p2) + 1, dp2);
+ dirlist2++;
+ }
+ }
+}
+#endif
+
+
+
extern int diff_main(int argc, char **argv) {
char *ep;
int gotstdin = 0;
projects / oweals / busybox.git / commitdiff