busybox/coreutils/diff.c
2006-04-18 20:41:51 +00:00

1272 lines
39 KiB
C

/* 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>
* Copyright (c) 2003 Todd C. Miller <Todd.Miller@courtesan.com>
*
* 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.
*
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
#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<<0)
#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<<0)
#define FLAG_b (1<<1)
#define FLAG_d (1<<2)
#define FLAG_i (1<<3)
#define FLAG_L (1<<4)
#define FLAG_N (1<<5)
#define FLAG_q (1<<6)
#define FLAG_r (1<<7)
#define FLAG_s (1<<8)
#define FLAG_S (1<<9)
#define FLAG_t (1<<10)
#define FLAG_T (1<<11)
#define FLAG_U (1<<12)
#define FLAG_w (1<<13)
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 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)
{
const char * const _entry = entry ? entry : "";
char *_path1 = entry ? concat_path_file(path1, _entry) : path1;
char *_path2 = entry ? concat_path_file(path2, _entry) : path2;
switch (val) {
case D_ONLY:
print_only(path1, strlen(path1), entry);
break;
case D_COMMON:
printf("Common subdirectories: %s and %s\n", _path1, _path2);
break;
case D_BINARY:
printf("Binary files %s and %s differ\n", _path1, _path2);
break;
case D_DIFFER:
if (cmd_flags & FLAG_q)
printf("Files %s and %s differ\n", _path1, _path2);
break;
case D_SAME:
if (cmd_flags & FLAG_s)
printf("Files %s and %s are identical\n", _path1, _path2);
break;
case D_MISMATCH1:
printf("File %s is a directory while file %s is a regular file\n",
_path1, _path2);
break;
case D_MISMATCH2:
printf("File %s is a regular file while file %s is a directory\n",
_path1, _path2);
break;
case D_SKIPPED1:
printf("File %s is not a regular file or directory and was skipped\n",
_path1);
break;
case D_SKIPPED2:
printf("File %s is not a regular file or directory and was skipped\n",
_path2);
break;
}
if (entry) {
free(_path1);
free(_path2);
}
}
/*
* 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);
}
/*
* 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 h;
size_t j, 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 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;
u_int numtries;
#if ENABLE_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 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;
}
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);
}
/*
* 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(FILE *f1, 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 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);
}
static int fetch(long *f, int a, int b, FILE *lb, int ch)
{
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);
}
static int asciifile(FILE *f)
{
#if ENABLE_FEATURE_DIFF_BINARY
unsigned char buf[BUFSIZ];
int i, cnt;
#endif
if ((cmd_flags & FLAG_a) || f == NULL)
return (1);
#if ENABLE_FEATURE_DIFF_BINARY
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';
#if 0
switch (ch) {
case 'c':
fetch(ixold, lowa, a - 1, f1, ' ');
fetch(ixold, a, b, f1, '-');
fetch(ixnew, c, d, f2, '+');
break;
case 'd':
fetch(ixold, lowa, a - 1, f1, ' ');
fetch(ixold, a, b, f1, '-');
break;
case 'a':
fetch(ixnew, lowc, c - 1, f2, ' ');
fetch(ixnew, c, d, f2, '+');
break;
}
#else
if (ch == 'c' || ch == 'd') {
fetch(ixold, lowa, a - 1, f1, ' ');
fetch(ixold, a, b, f1, '-');
}
if (ch == 'a')
fetch(ixnew, lowc, c - 1, f2, ' ');
if (ch == 'c' || ch == 'a')
fetch(ixnew, c, d, f2, '+');
#endif
lowa = b + 1;
lowc = d + 1;
}
fetch(ixnew, d + 1, upd, f2, ' ');
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));
}
/*
* 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)
{
/* Note that j0 and j1 can't be used as they are defined in math.h.
* This also allows the rather amusing variable 'j00'... */
int m, i0, i1, j00, j01;
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++;
j00 = J[i0 - 1] + 1;
i1 = i0 - 1;
while (i1 < m && J[i1 + 1] == 0)
i1++;
j01 = J[i1 + 1] - 1;
J[i1] = j01;
change(file1, f1, file2, f2, i0, i1, j00, j01);
}
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");
}
if ((i=files_differ(f1, f2, flags)) == 0)
goto closem;
else if (i != 1) {/* 1 == ok */
/* 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(f1, 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
#if ENABLE_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 ATTRIBUTE_UNUSED *sb, 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;
char **retval;
/* 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;
/* Reset dl_count - there's no need to free dl as bb_xrealloc does
* the job nicely. */
dl_count = 0;
/* 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;
dp = bb_opendir(path);
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. */
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
int diff_main(int argc, char **argv) {
char *ep;
int gotstdin = 0;
char *U_opt;
llist_t *L_arg = NULL;
bb_opt_complementally = "L::";
cmd_flags = bb_getopt_ulflags(argc, argv, "abdiL:NqrsS:tTU:wu", &L_arg, &start, &U_opt);
if (cmd_flags & FLAG_L) {
while (L_arg) {
if (label[0] == NULL)
label[0] = L_arg->data;
else if (label[1] == NULL)
label[1] = L_arg->data;
else
bb_show_usage();
L_arg = L_arg->link;
}
/* If both label[0] and label[1] were set, they need to be swapped. */
if (label[0] && label[1]) {
char *tmp;
tmp = label[1];
label[1] = label[0];
label[0] = tmp;
}
}
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)) {
#if ENABLE_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);
}