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show-diff.c
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show-diff.c
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/*
* GIT - The information manager from hell
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
static char *diff_cmd = "diff -L '%s' -u -N - '%s'";
/* Help to copy the thing properly quoted for the shell safety.
* any single quote is replaced with '\'', and the caller is
* expected to enclose the result within a single quote pair.
*
* E.g.
* original sq_expand result
* name ==> name ==> 'name'
* a b ==> a b ==> 'a b'
* a'b ==> a'\''b ==> 'a'\''b'
*
* NOTE! The returned memory belongs to this function so
* do not free it.
*/
static char *sq_expand(char *src)
{
static char *buf = NULL;
static int buf_size = -1;
int cnt, c;
char *cp;
/* count single quote characters */
for (cnt = 0, cp = src; *cp; cnt++, cp++)
if (*cp == '\'')
cnt += 3;
if (buf_size < cnt) {
free(buf);
buf_size = cnt;
buf = malloc(cnt);
}
cp = buf;
while ((c = *src++)) {
if (c != '\'')
*cp++ = c;
else {
cp = strcpy(cp, "'\\''");
cp += 4;
}
}
*cp = 0;
return buf;
}
static void show_differences(char *name, void *old_contents,
unsigned long long old_size)
{
FILE *f;
static char *cmd = NULL;
static int cmd_size = -1;
char *name_sq = sq_expand(name);
int cmd_required_length = strlen(name_sq) * 2 + strlen(diff_cmd);
if (cmd_size < cmd_required_length) {
free(cmd);
cmd_size = cmd_required_length;
cmd = malloc(cmd_required_length);
}
snprintf(cmd, cmd_size, diff_cmd, name_sq, name_sq);
f = popen(cmd, "w");
if (old_size)
fwrite(old_contents, old_size, 1, f);
pclose(f);
}
static void show_diff_empty(struct cache_entry *ce)
{
char *old;
unsigned long int size;
int lines=0;
unsigned char type[20], *p, *end;
old = read_sha1_file(ce->sha1, type, &size);
if (size > 0) {
int startline = 1;
int c = 0;
printf("--- %s\n", ce->name);
printf("+++ /dev/null\n");
p = old;
end = old + size;
while (p < end)
if (*p++ == '\n')
lines ++;
printf("@@ -1,%d +0,0 @@\n", lines);
p = old;
while (p < end) {
c = *p++;
if (startline) {
putchar('-');
startline = 0;
}
putchar(c);
if (c == '\n')
startline = 1;
}
if (c!='\n')
printf("\n");
fflush(stdout);
}
}
static const char *show_diff_usage = "show-diff [-q] [-s] [-z] [paths...]";
static int matches_pathspec(struct cache_entry *ce, char **spec, int cnt)
{
int i;
int namelen = ce_namelen(ce);
for (i = 0; i < cnt; i++) {
int speclen = strlen(spec[i]);
if (! strncmp(spec[i], ce->name, speclen) &&
speclen <= namelen &&
(ce->name[speclen] == 0 ||
ce->name[speclen] == '/'))
return 1;
}
return 0;
}
int main(int argc, char **argv)
{
int silent = 0;
int silent_on_nonexisting_files = 0;
int machine_readable = 0;
int entries = read_cache();
int i;
while (1 < argc && argv[1][0] == '-') {
if (!strcmp(argv[1], "-s"))
silent_on_nonexisting_files = silent = 1;
else if (!strcmp(argv[1], "-q"))
silent_on_nonexisting_files = 1;
else if (!strcmp(argv[1], "-z"))
machine_readable = 1;
else
usage(show_diff_usage);
argv++; argc--;
}
/* At this point, if argc == 1, then we are doing everything.
* Otherwise argv[1] .. argv[argc-1] have the explicit paths.
*/
if (entries < 0) {
perror("read_cache");
exit(1);
}
for (i = 0; i < entries; i++) {
struct stat st;
struct cache_entry *ce = active_cache[i];
int changed;
unsigned long size;
char type[20];
void *old;
if (1 < argc &&
! matches_pathspec(ce, argv+1, argc-1))
continue;
if (ce_stage(ce)) {
if (machine_readable)
printf("U %s%c", ce->name, 0);
else
printf("%s: Unmerged\n",
ce->name);
while (i < entries &&
!strcmp(ce->name, active_cache[i]->name))
i++;
i--; /* compensate for loop control increments */
continue;
}
if (stat(ce->name, &st) < 0) {
if (errno == ENOENT && silent_on_nonexisting_files)
continue;
if (machine_readable)
printf("X %s%c", ce->name, 0);
else {
printf("%s: %s\n", ce->name, strerror(errno));
if (errno == ENOENT)
show_diff_empty(ce);
}
continue;
}
changed = cache_match_stat(ce, &st);
if (!changed)
continue;
if (!machine_readable)
printf("%s: %s\n", ce->name, sha1_to_hex(ce->sha1));
else {
printf("%s %s%c", sha1_to_hex(ce->sha1), ce->name, 0);
continue;
}
fflush(stdout);
if (silent)
continue;
old = read_sha1_file(ce->sha1, type, &size);
show_differences(ce->name, old, size);
free(old);
}
return 0;
}