--- /dev/null
+/* vi: set sw=4 ts=4: */
+/*
+ * 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
+ * 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.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ * Sponsored in part by the Defense Advanced Research Projects
+ * Agency (DARPA) and Air Force Research Laboratory, Air Force
+ * Materiel Command, USAF, under agreement number F39502-99-1-0512.
+ */
+
+#include <time.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/stat.h>
+#include <ctype.h>
+#include <errno.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <stdarg.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/wait.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <paths.h>
+#include <dirent.h>
+#include "busybox.h"
+
+#define FSIZE_MAX 32768
+
+/*
+ * Output flags
+ */
+#define D_HEADER 1 /* Print a header/footer between files */
+#define D_EMPTY1 2 /* Treat first file as empty (/dev/null) */
+#define D_EMPTY2 4 /* Treat second file as empty (/dev/null) */
+
+/*
+ * Status values for print_status() and diffreg() return values
+ * Guide:
+ * D_SAME - files are the same
+ * D_DIFFER - files differ
+ * D_BINARY - binary files differ
+ * D_COMMON - subdirectory common to both dirs
+ * D_ONLY - file only exists in one dir
+ * D_MISMATCH1 - path1 a dir, path2 a file
+ * D_MISMATCH2 - path1 a file, path2 a dir
+ * D_ERROR - error occurred
+ * D_SKIPPED1 - skipped path1 as it is a special file
+ * D_SKIPPED2 - skipped path2 as it is a special file
+ */
+
+#define D_SAME 0
+#define D_DIFFER 1
+#define D_BINARY (1<<1)
+#define D_COMMON (1<<2)
+#define D_ONLY (1<<3)
+#define D_MISMATCH1 (1<<4)
+#define D_MISMATCH2 (1<<5)
+#define D_ERROR (1<<6)
+#define D_SKIPPED1 (1<<7)
+#define D_SKIPPED2 (1<<8)
+
+/* Command line options */
+static unsigned long cmd_flags;
+#define FLAG_a 1
+#define FLAG_b (1<<1)
+#define FLAG_d (1<<2)
+#define FLAG_i (1<<3)
+#define FLAG_N (1<<4)
+#define FLAG_q (1<<5)
+#define FLAG_r (1<<6)
+#define FLAG_s (1<<7)
+#define FLAG_S (1<<8)
+#define FLAG_t (1<<9)
+#define FLAG_T (1<<10)
+#define FLAG_U (1<<11)
+#define FLAG_w (1<<12)
+
+int context, status;
+char *start, *label[2];
+struct stat stb1, stb2;
+char **dl;
+int dl_count = 0;
+
+struct cand {
+ int x;
+ int y;
+ int pred;
+};
+
+struct line {
+ int serial;
+ int value;
+} *file[2];
+
+/*
+ * The following struct is used to record change information
+ * doing a "context" or "unified" diff. (see routine "change" to
+ * understand the highly mnemonic field names)
+ */
+struct context_vec {
+ int a; /* start line in old file */
+ int b; /* end line in old file */
+ int c; /* start line in new file */
+ int d; /* end line in new file */
+};
+
+static int *J; /* will be overlaid on class */
+static int *class; /* will be overlaid on file[0] */
+static int *klist; /* will be overlaid on file[0] after class */
+static int *member; /* will be overlaid on file[1] */
+static int clen;
+static int len[2];
+static int pref, suff; /* length of prefix and suffix */
+static int slen[2];
+static int anychange;
+static long *ixnew; /* will be overlaid on file[1] */
+static long *ixold; /* will be overlaid on klist */
+static struct cand *clist; /* merely a free storage pot for candidates */
+static int clistlen; /* the length of clist */
+static struct line *sfile[2]; /* shortened by pruning common prefix/suffix */
+static struct context_vec *context_vec_start;
+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)
+{
+ 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)
+{
+ switch (val) {
+ case D_ONLY:
+ print_only(path1, strlen(path1), entry);
+ break;
+ case D_COMMON:
+ printf("Common subdirectories: %s%s and %s%s\n",
+ path1, entry ? entry : "", path2, entry ? entry : "");
+ break;
+ case D_BINARY:
+ printf("Binary files %s%s and %s%s differ\n",
+ path1, entry ? entry : "", path2, entry ? entry : "");
+ break;
+ case D_DIFFER:
+ if (cmd_flags & FLAG_q)
+ printf("Files %s%s and %s%s differ\n",
+ path1, entry ? entry : "",
+ path2, entry ? entry : "");
+ break;
+ case D_SAME:
+ if (cmd_flags & FLAG_s)
+ printf("Files %s%s and %s%s are identical\n",
+ path1, entry ? entry : "",
+ path2, entry ? entry : "");
+ break;
+ case D_MISMATCH1:
+ printf("File %s%s is a directory while file %s%s is a regular file\n",
+ path1, entry ? entry : "", path2, entry ? entry : "");
+ break;
+ case D_MISMATCH2:
+ printf("File %s%s is a regular file while file %s%s is a directory\n",
+ path1, entry ? entry : "", path2, entry ? entry : "");
+ break;
+ case D_SKIPPED1:
+ printf("File %s%s is not a regular file or directory and was skipped\n",
+ path1, entry ? entry : "");
+ break;
+ case D_SKIPPED2:
+ printf("File %s%s is not a regular file or directory and was skipped\n",
+ path2, entry ? entry : "");
+ break;
+ }
+}
+
+/*
+ * 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);
+}
+
+/*
+ * 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)
+{
+ char buf1[BUFSIZ], buf2[BUFSIZ];
+ size_t i, j;
+
+ if ((flags & (D_EMPTY1|D_EMPTY2)) || stb1.st_size != stb2.st_size ||
+ (stb1.st_mode & S_IFMT) != (stb2.st_mode & S_IFMT))
+ return (1);
+ while(1) {
+ i = fread(buf1, 1, sizeof(buf1), f1);
+ j = fread(buf2, 1, sizeof(buf2), f2);
+ if (i != j)
+ return (1);
+ if (i == 0 && j == 0) {
+ if (ferror(f1) || ferror(f2))
+ return (1);
+ return (0);
+ }
+ if (memcmp(buf1, buf2, i) != 0)
+ return (1);
+ }
+}
+
+static void
+prepare(int i, FILE *fd, off_t filesize)
+{
+ struct line *p;
+ int j, h;
+ size_t sz;
+
+ rewind(fd);
+
+ sz = (filesize <= FSIZE_MAX ? filesize : FSIZE_MAX) / 25;
+ if (sz < 100)
+ sz = 100;
+
+ p = xmalloc((sz + 3) * sizeof(struct line));
+ for (j = 0; (h = readhash(fd));) {
+ if (j == sz) {
+ sz = sz * 3 / 2;
+ p = xrealloc(p, (sz + 3) * sizeof(struct line));
+ }
+ p[++j].value = h;
+ }
+ len[i] = j;
+ file[i] = p;
+}
+
+static void
+prune(void)
+{
+ int i, j;
+
+ for (pref = 0; pref < len[0] && pref < len[1] &&
+ file[0][pref + 1].value == file[1][pref + 1].value;
+ pref++)
+ ;
+ for (suff = 0; suff < len[0] - pref && suff < len[1] - pref &&
+ file[0][len[0] - suff].value == file[1][len[1] - suff].value;
+ suff++)
+ ;
+ for (j = 0; j < 2; j++) {
+ sfile[j] = file[j] + pref;
+ slen[j] = len[j] - pref - suff;
+ for (i = 0; i <= slen[j]; i++)
+ sfile[j][i].serial = i;
+ }
+}
+
+static void
+equiv(struct line *a, int n, struct line *b, int m, int *c)
+{
+ int i, j;
+
+ i = j = 1;
+ while (i <= n && j <= m) {
+ if (a[i].value < b[j].value)
+ a[i++].value = 0;
+ else if (a[i].value == b[j].value)
+ a[i++].value = j;
+ else
+ j++;
+ }
+ while (i <= n)
+ a[i++].value = 0;
+ b[m + 1].value = 0;
+ j = 0;
+ while (++j <= m) {
+ c[j] = -b[j].serial;
+ while (b[j + 1].value == b[j].value) {
+ j++;
+ c[j] = b[j].serial;
+ }
+ }
+ c[j] = -1;
+}
+
+static int isqrt(int n) {
+ int y, x = 1;
+ if (n == 0) return(0);
+
+ do {
+ y = x;
+ x = n / x;
+ x += y;
+ x /= 2;
+ } while ((x - y) > 1 || (x - y) < -1);
+
+ return (x);
+}
+
+static int
+stone(int *a, int n, int *b, int *c)
+{
+ int i, k, y, j, l;
+ int oldc, tc, oldl;
+ u_int numtries;
+#ifdef CONFIG_FEATURE_DIFF_MINIMAL
+ const u_int bound = (cmd_flags & FLAG_d) ? UINT_MAX : MAX(256, isqrt(n));
+#else
+ const u_int bound = MAX(256, isqrt(n));
+#endif
+ k = 0;
+ c[0] = newcand(0, 0, 0);
+ for (i = 1; i <= n; i++) {
+ j = a[i];
+ if (j == 0)
+ continue;
+ y = -b[j];
+ oldl = 0;
+ oldc = c[0];
+ numtries = 0;
+ do {
+ if (y <= clist[oldc].y)
+ continue;
+ l = search(c, k, y);
+ if (l != oldl + 1)
+ oldc = c[l - 1];
+ if (l <= k) {
+ if (clist[c[l]].y <= y)
+ continue;
+ tc = c[l];
+ c[l] = newcand(i, y, oldc);
+ oldc = tc;
+ oldl = l;
+ numtries++;
+ } else {
+ c[l] = newcand(i, y, oldc);
+ k++;
+ break;
+ }
+ } while ((y = b[++j]) > 0 && numtries < bound);
+ }
+ return (k);
+}
+
+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 void
+unravel(int p)
+{
+ struct cand *q;
+ int i;
+
+ 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;
+}
+
+/*
+ * 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)
+{
+ int i, j, jackpot, c, d;
+ long ctold, ctnew;
+
+ rewind(f1);
+ rewind(f2);
+ j = 1;
+ ixold[0] = ixnew[0] = 0;
+ jackpot = 0;
+ ctold = ctnew = 0;
+ for (i = 1; i <= len[0]; i++) {
+ if (J[i] == 0) {
+ ixold[i] = ctold += skipline(f1);
+ continue;
+ }
+ while (j < J[i]) {
+ ixnew[j] = ctnew += skipline(f2);
+ j++;
+ }
+ if ((cmd_flags & FLAG_b) || (cmd_flags & FLAG_w) || (cmd_flags & FLAG_i)) {
+ while (1) {
+ c = getc(f1);
+ d = getc(f2);
+ /*
+ * GNU diff ignores a missing newline
+ * in one file if bflag || wflag.
+ */
+ if (((cmd_flags & FLAG_b) || (cmd_flags & FLAG_w)) &&
+ ((c == EOF && d == '\n') ||
+ (c == '\n' && d == EOF))) {
+ break;
+ }
+ ctold++;
+ ctnew++;
+ if ((cmd_flags & FLAG_b) && isspace(c) && isspace(d)) {
+ do {
+ if (c == '\n')
+ break;
+ ctold++;
+ } while (isspace(c = getc(f1)));
+ do {
+ if (d == '\n')
+ break;
+ ctnew++;
+ } while (isspace(d = getc(f2)));
+ } else if (cmd_flags & FLAG_w) {
+ while (isspace(c) && c != '\n') {
+ c = getc(f1);
+ ctold++;
+ }
+ while (isspace(d) && d != '\n') {
+ d = getc(f2);
+ ctnew++;
+ }
+ }
+ if (c != d) {
+ jackpot++;
+ J[i] = 0;
+ if (c != '\n' && c != EOF)
+ ctold += skipline(f1);
+ if (d != '\n' && c != EOF)
+ ctnew += skipline(f2);
+ break;
+ }
+ if (c == '\n' || c == EOF)
+ break;
+ }
+ } else {
+ while (1) {
+ ctold++;
+ ctnew++;
+ if ((c = getc(f1)) != (d = getc(f2))) {
+ J[i] = 0;
+ if (c != '\n' && c != EOF)
+ ctold += skipline(f1);
+ if (d != '\n' && c != EOF)
+ ctnew += skipline(f2);
+ break;
+ }
+ if (c == '\n' || c == EOF)
+ break;
+ }
+ }
+ ixold[i] = ctold;
+ ixnew[j] = ctnew;
+ j++;
+ }
+ for (; j <= len[1]; j++)
+ ixnew[j] = ctnew += skipline(f2);
+}
+
+/* shellsort CACM #201 */
+static void
+sort(struct line *a, int n)
+{
+ struct line *ai, *aim, w;
+ int j, m = 0, k;
+
+ if (n == 0)
+ return;
+ for (j = 1; j <= n; j *= 2)
+ m = 2 * j - 1;
+ for (m /= 2; m != 0; m /= 2) {
+ k = n - m;
+ for (j = 1; j <= k; j++) {
+ for (ai = &a[j]; ai > a; ai -= m) {
+ aim = &ai[m];
+ if (aim < ai)
+ break; /* wraparound */
+ if (aim->value > ai[0].value ||
+ (aim->value == ai[0].value &&
+ aim->serial > ai[0].serial))
+ break;
+ w.value = ai[0].value;
+ ai[0].value = aim->value;
+ aim->value = w.value;
+ w.serial = ai[0].serial;
+ ai[0].serial = aim->serial;
+ aim->serial = w.serial;
+ }
+ }
+ }
+}
+
+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)
+{
+ int i, c;
+
+ for (i = 1; (c = getc(f)) != '\n' && c != EOF; i++)
+ continue;
+ return (i);
+}
+
+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);
+ }
+}
+
+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;
+
+ if (a > b)
+ return (0);
+ for (i = a; i <= b; i++) {
+ fseek(lb, f[i - 1], SEEK_SET);
+ nc = f[i] - f[i - 1];
+ if (ch != '\0') {
+ putchar(ch);
+ if (cmd_flags & FLAG_T)
+ putchar('\t');
+ }
+ col = 0;
+ for (j = 0, lastc = '\0'; j < nc; j++, lastc = c) {
+ if ((c = getc(lb)) == EOF) {
+ puts("\n\\ No newline at end of file");
+ return (0);
+ }
+ if (c == '\t' && (cmd_flags & FLAG_t)) {
+ do {
+ putchar(' ');
+ } while (++col & 7);
+ } else {
+ putchar(c);
+ col++;
+ }
+ }
+ }
+ 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)
+{
+
+ 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++)
+ if (!isprint(buf[i]) && !isspace(buf[i]))
+ return (0);
+#endif
+ return (1);
+}
+
+/* dump accumulated "unified" diff changes */
+static void
+dump_unified_vec(FILE *f1, FILE *f2)
+{
+ struct context_vec *cvp = context_vec_start;
+ int lowa, upb, lowc, upd;
+ int a, b, c, d;
+ char ch;
+
+ if (context_vec_start > context_vec_ptr)
+ return;
+
+ b = d = 0; /* gcc */
+ lowa = MAX(1, cvp->a - context);
+ upb = MIN(len[0], context_vec_ptr->b + context);
+ lowc = MAX(1, cvp->c - context);
+ upd = MIN(len[1], context_vec_ptr->d + context);
+
+ fputs("@@ -", stdout);
+ uni_range(lowa, upb);
+ fputs(" +", stdout);
+ uni_range(lowc, upd);
+ fputs(" @@", stdout);
+ putchar('\n');
+
+ /*
+ * Output changes in "unified" diff format--the old and new lines
+ * are printed together.
+ */
+ for (; cvp <= context_vec_ptr; cvp++) {
+ a = cvp->a;
+ b = cvp->b;
+ c = cvp->c;
+ d = cvp->d;
+
+ /*
+ * c: both new and old changes
+ * d: only changes in the old file
+ * a: only changes in the new file
+ */
+ if (a <= b && c <= d)
+ ch = 'c';
+ else
+ ch = (a <= b) ? 'd' : 'a';
+
+ switch (ch) {
+ case 'c':
+ fetch(ixold, lowa, a - 1, f1, ' ', 0);
+ fetch(ixold, a, b, f1, '-', 0);
+ fetch(ixnew, c, d, f2, '+', 0);
+ break;
+ case 'd':
+ fetch(ixold, lowa, a - 1, f1, ' ', 0);
+ fetch(ixold, a, b, f1, '-', 0);
+ break;
+ case 'a':
+ fetch(ixnew, lowc, c - 1, f2, ' ', 0);
+ fetch(ixnew, c, d, f2, '+', 0);
+ break;
+ }
+ lowa = b + 1;
+ lowc = d + 1;
+ }
+ fetch(ixnew, d + 1, upd, f2, ' ', 0);
+
+ context_vec_ptr = context_vec_start - 1;
+}
+
+static void
+print_header(const char *file1, const char *file2)
+{
+ if (label[0] != NULL)
+ printf("%s %s\n", "---",
+ label[0]);
+ else
+ printf("%s %s\t%s", "---",
+ file1, ctime(&stb1.st_mtime));
+ if (label[1] != NULL)
+ printf("%s %s\n", "+++",
+ label[1]);
+ else
+ printf("%s %s\t%s", "+++",
+ file2, ctime(&stb2.st_mtime));
+}
+
+extern int diff_main(int argc, char **argv) {
+ char *ep;
+ int gotstdin = 0;
+
+ char *U_opt;
+ cmd_flags = bb_getopt_ulflags(argc, argv, "abdiNqrsS:tTU:wu", &start, &U_opt);
+
+ context = 3; /* This is the default number of lines of context. */
+ if (cmd_flags & FLAG_U) {
+ context = strtol(U_opt, &ep, 10);
+ if (context == 0) {
+ bb_error_msg("Invalid context length");
+ bb_show_usage();
+ }
+ }
+ argc -= optind;
+ argv += optind;
+
+ /*
+ * Do sanity checks, fill in stb1 and stb2 and call the appropriate
+ * driver routine. Both drivers use the contents of stb1 and stb2.
+ */
+ if (argc < 2) {
+ bb_error_msg("Missing filename");
+ bb_show_usage();
+ }
+ if (strcmp(argv[0], "-") == 0) {
+ fstat(STDIN_FILENO, &stb1);
+ gotstdin = 1;
+ } else if (stat(argv[0], &stb1) != 0)
+ bb_perror_msg_and_die("Couldn't stat %s", argv[0]);
+ if (strcmp(argv[1], "-") == 0) {
+ fstat(STDIN_FILENO, &stb2);
+ gotstdin = 1;
+ } else if (stat(argv[1], &stb2) != 0)
+ bb_perror_msg_and_die("Couldn't stat %s", argv[1]);
+ if (gotstdin && (S_ISDIR(stb1.st_mode) || S_ISDIR(stb2.st_mode)))
+ bb_error_msg_and_die("Can't compare - to a directory");
+ if (S_ISDIR(stb1.st_mode) && S_ISDIR(stb2.st_mode)) {
+#ifdef CONFIG_FEATURE_DIFF_DIR
+ diffdir(argv[0], argv[1]);
+#else
+ bb_error_msg_and_die("Directory comparison not supported");
+#endif
+ }
+ else {
+ if (S_ISDIR(stb1.st_mode)) {
+ argv[0] = concat_path_file(argv[0], argv[1]);
+ if (stat(argv[0], &stb1) < 0)
+ bb_perror_msg_and_die("Couldn't stat %s", argv[0]);
+ }
+ if (S_ISDIR(stb2.st_mode)) {
+ argv[1] = concat_path_file(argv[1], argv[0]);
+ if (stat(argv[1], &stb2) < 0)
+ bb_perror_msg_and_die("Couldn't stat %s", argv[1]);
+ }
+ print_status(diffreg(argv[0], argv[1], 0), argv[0], argv[1], NULL);
+ }
+ exit(status);
+}
+
projects / oweals / busybox.git / commitdiff