From 8f7d38970046c0ea53de911084561b79ffb2d6b9 Mon Sep 17 00:00:00 2001 From: Bernhard Reutner-Fischer Date: Thu, 6 Apr 2006 08:11:08 +0000 Subject: [PATCH] - new applet diff. Rob Sullivan writes: Here's my attempt at a mini diff applet - it's adapted from the code at http://www.openbsd.org/cgi-bin/cvsweb/src/usr.bin/diff/, and only supports unified diffs. I've busyboxified everything to a reasonable degree, so I think the code is suitable enough to be included, but there's still a fair bit of cleaning up to be done. --- coreutils/Config.in | 32 ++ coreutils/Makefile.in | 1 + coreutils/diff.c | 1277 +++++++++++++++++++++++++++++++++++++++++ include/applets.h | 1 + include/usage.h | 20 + 5 files changed, 1331 insertions(+) create mode 100644 coreutils/diff.c diff --git a/coreutils/Config.in b/coreutils/Config.in index cd45cc077..62c5c327d 100644 --- a/coreutils/Config.in +++ b/coreutils/Config.in @@ -109,6 +109,38 @@ config CONFIG_DF df reports the amount of disk space used and available on filesystems. +config CONFIG_DIFF + bool "diff" + default n + help + diff compares two files or directories and outputs the + differences between them in a form that can be given to + the patch command. + +config CONFIG_FEATURE_DIFF_BINARY + bool " Enable checks for binary files" + default y + depends on CONFIG_DIFF + help + This option enables support for checking for binary files + before a comparison is carried out. + +config CONFIG_FEATURE_DIFF_DIR + bool " Enable directory support" + default y + depends on CONFIG_DIFF + help + This option enables support for directory and subdirectory + comparison. + +config CONFIG_FEATURE_DIFF_MINIMAL + bool " Enable -d option to find smaller sets of changes" + default n + depends on CONFIG_DIFF + help + Enabling this option allows the use of -d to make diff + try hard to find the smallest possible set of changes. + config CONFIG_DIRNAME bool "dirname" default n diff --git a/coreutils/Makefile.in b/coreutils/Makefile.in index 2ab256c15..ff0e89b4d 100644 --- a/coreutils/Makefile.in +++ b/coreutils/Makefile.in @@ -25,6 +25,7 @@ COREUTILS-$(CONFIG_CUT) += cut.o COREUTILS-$(CONFIG_DATE) += date.o COREUTILS-$(CONFIG_DD) += dd.o COREUTILS-$(CONFIG_DF) += df.o +COREUTILS-$(CONFIG_DIFF) += diff.o COREUTILS-$(CONFIG_DIRNAME) += dirname.o COREUTILS-$(CONFIG_DOS2UNIX) += dos2unix.o COREUTILS-$(CONFIG_DU) += du.o diff --git a/coreutils/diff.c b/coreutils/diff.c new file mode 100644 index 000000000..b2945dd87 --- /dev/null +++ b/coreutils/diff.c @@ -0,0 +1,1277 @@ +/* vi: set sw=4 ts=4: */ +/* + * Mini diff implementation for busybox, adapted from OpenBSD diff. + * + * Copyright (C) 2006 by Robert Sullivan + * + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +/* + * Copyright (c) 2003 Todd C. Miller + * + * 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 +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#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); +} + diff --git a/include/applets.h b/include/applets.h index 0f239822c..f0c6f7a0e 100644 --- a/include/applets.h +++ b/include/applets.h @@ -86,6 +86,7 @@ USE_DELGROUP(APPLET(delgroup, delgroup_main, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_DELUSER(APPLET(deluser, deluser_main, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_DEVFSD(APPLET(devfsd, devfsd_main, _BB_DIR_SBIN, _BB_SUID_NEVER)) USE_DF(APPLET(df, df_main, _BB_DIR_BIN, _BB_SUID_NEVER)) +USE_DIFF(APPLET(diff, diff_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_DIRNAME(APPLET(dirname, dirname_main, _BB_DIR_USR_BIN, _BB_SUID_NEVER)) USE_DMESG(APPLET(dmesg, dmesg_main, _BB_DIR_BIN, _BB_SUID_NEVER)) USE_DNSD(APPLET(dnsd, dnsd_main, _BB_DIR_USR_SBIN, _BB_SUID_ALWAYS)) diff --git a/include/usage.h b/include/usage.h index 0ac0284ce..2eb548bcf 100644 --- a/include/usage.h +++ b/include/usage.h @@ -453,6 +453,26 @@ "Filesystem 1k-blocks Used Available Use% Mounted on\n" \ "/dev/sda3 8690864 8553540 137324 98% /\n" +#define diff_trivial_usage \ + "[-abdiNqrTstw] [-S FILE] [-U LINES] FILE1 FILE2" +#define diff_full_usage \ + "Compare files line by line and output the differences between them.\n" \ + "This diff implementation only supports unified diffs.\n\n" \ + "Options:\n" \ + "\t-a\tTreat all files as text\n" \ + "\t-b\tIgnore changes in the amount of whitespace\n" \ + "\t-d\tTry hard to find a smaller set of changes\n" \ + "\t-i\tIgnore case differences\n" \ + "\t-N\tTreat absent files as empty\n" \ + "\t-q\tOutput only whether files differ\n" \ + "\t-r\tRecursively compare any subdirectories\n" \ + "\t-S\tStart with FILE when comparing directories\n" \ + "\t-T\tMake tabs line up by prefixing a tab when necessary\n" \ + "\t-s\tReport when two files are the same\n" \ + "\t-t\tExpand tabs to spaces in output\n" \ + "\t-U\tOutput LINES lines of context\n" \ + "\t-w\tIgnore all whitespace\n" + #define dirname_trivial_usage \ "FILENAME" #define dirname_full_usage \