git/rev-parse.c
Junio C Hamano 5bb2c65aba [PATCH] Help scripts that use git-rev-parse to grok args with SP/TAB/LF
The git-rev-parse command uses LF to separate each argument it
parses, so its users at least need to set IFS to LF to be able
to handle filenames with embedded SPs and TABs.  Some commands,
however, can take and do expect arguments with embedded LF,
notably, "-S" (pickaxe) of diff family, so even this workaround
does not work for them.

When --sq flag to git-rev-parse is given, instead of showing one
argument per line, it outputs arguments quoted for consumption
with "eval" by the caller, to remedy this situation.

As an example, this patch converts git-whatchanged to use this
new feature.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-22 20:34:16 -07:00

413 lines
7.4 KiB
C

/*
* rev-parse.c
*
* Copyright (C) Linus Torvalds, 2005
*/
#include "cache.h"
#include "commit.h"
#include "refs.h"
static char *def = NULL;
static int no_revs = 0;
static int single_rev = 0;
static int revs_only = 0;
static int do_rev_argument = 1;
static int output_revs = 0;
static int flags_only = 0;
static int no_flags = 0;
static int output_sq = 0;
#define NORMAL 0
#define REVERSED 1
static int show_type = NORMAL;
static int get_extended_sha1(char *name, unsigned char *sha1);
/*
* Some arguments are relevant "revision" arguments,
* others are about output format or other details.
* This sorts it all out.
*/
static int is_rev_argument(const char *arg)
{
static const char *rev_args[] = {
"--max-count=",
"--max-age=",
"--min-age=",
"--merge-order",
NULL
};
const char **p = rev_args;
for (;;) {
const char *str = *p++;
int len;
if (!str)
return 0;
len = strlen(str);
if (!strncmp(arg, str, len))
return 1;
}
}
static void show(const char *arg)
{
if (output_sq) {
int sq = '\'', ch;
putchar(sq);
while ((ch = *arg++)) {
if (ch == sq)
fputs("'\\'", stdout);
putchar(ch);
}
putchar(sq);
putchar(' ');
}
else
puts(arg);
}
static void show_rev(int type, const unsigned char *sha1)
{
if (no_revs)
return;
output_revs++;
/* Hexadecimal string plus possibly a carret;
* this does not have to be quoted even under output_sq.
*/
printf("%s%s%c", type == show_type ? "" : "^", sha1_to_hex(sha1),
output_sq ? ' ' : '\n');
}
static void show_rev_arg(char *rev)
{
if (no_revs)
return;
show(rev);
}
static void show_norev(char *norev)
{
if (flags_only)
return;
if (revs_only)
return;
show(norev);
}
static void show_arg(char *arg)
{
if (no_flags)
return;
if (do_rev_argument && is_rev_argument(arg))
show_rev_arg(arg);
else
show_norev(arg);
}
static int get_parent(char *name, unsigned char *result, int idx)
{
unsigned char sha1[20];
int ret = get_extended_sha1(name, sha1);
struct commit *commit;
struct commit_list *p;
if (ret)
return ret;
commit = lookup_commit_reference(sha1);
if (!commit)
return -1;
if (parse_commit(commit))
return -1;
if (!idx) {
memcpy(result, commit->object.sha1, 20);
return 0;
}
p = commit->parents;
while (p) {
if (!--idx) {
memcpy(result, p->item->object.sha1, 20);
return 0;
}
p = p->next;
}
return -1;
}
static int find_short_object_filename(int len, const char *name, unsigned char *sha1)
{
static char dirname[PATH_MAX];
char hex[40];
DIR *dir;
int found;
snprintf(dirname, sizeof(dirname), "%s/%.2s", get_object_directory(), name);
dir = opendir(dirname);
sprintf(hex, "%.2s", name);
found = 0;
if (dir) {
struct dirent *de;
while ((de = readdir(dir)) != NULL) {
if (strlen(de->d_name) != 38)
continue;
if (memcmp(de->d_name, name + 2, len-2))
continue;
memcpy(hex + 2, de->d_name, 38);
if (++found > 1)
break;
}
closedir(dir);
}
if (found == 1)
return get_sha1_hex(hex, sha1) == 0;
return 0;
}
static int match_sha(unsigned len, const unsigned char *a, const unsigned char *b)
{
do {
if (*a != *b)
return 0;
a++;
b++;
len -= 2;
} while (len > 1);
if (len)
if ((*a ^ *b) & 0xf0)
return 0;
return 1;
}
static int find_short_packed_object(int len, const unsigned char *match, unsigned char *sha1)
{
struct packed_git *p;
prepare_packed_git();
for (p = packed_git; p; p = p->next) {
unsigned num = num_packed_objects(p);
unsigned first = 0, last = num;
while (first < last) {
unsigned mid = (first + last) / 2;
unsigned char now[20];
int cmp;
nth_packed_object_sha1(p, mid, now);
cmp = memcmp(match, now, 20);
if (!cmp) {
first = mid;
break;
}
if (cmp > 0) {
first = mid+1;
continue;
}
last = mid;
}
if (first < num) {
unsigned char now[20], next[20];
nth_packed_object_sha1(p, first, now);
if (match_sha(len, match, now)) {
if (nth_packed_object_sha1(p, first+1, next) || !match_sha(len, match, next)) {
memcpy(sha1, now, 20);
return 1;
}
}
}
}
return 0;
}
static int get_short_sha1(char *name, unsigned char *sha1)
{
int i;
char canonical[40];
unsigned char res[20];
memset(res, 0, 20);
memset(canonical, 'x', 40);
for (i = 0;;i++) {
unsigned char c = name[i];
unsigned char val;
if (!c || i > 40)
break;
if (c >= '0' && c <= '9')
val = c - '0';
else if (c >= 'a' && c <= 'f')
val = c - 'a' + 10;
else if (c >= 'A' && c <='F') {
val = c - 'A' + 10;
c -= 'A' - 'a';
}
else
return -1;
canonical[i] = c;
if (!(i & 1))
val <<= 4;
res[i >> 1] |= val;
}
if (i < 4)
return -1;
if (find_short_object_filename(i, canonical, sha1))
return 0;
if (find_short_packed_object(i, res, sha1))
return 0;
return -1;
}
/*
* This is like "get_sha1()", except it allows "sha1 expressions",
* notably "xyz^" for "parent of xyz"
*/
static int get_extended_sha1(char *name, unsigned char *sha1)
{
int parent, ret;
int len = strlen(name);
parent = 1;
if (len > 2 && name[len-1] >= '0' && name[len-1] <= '9') {
parent = name[len-1] - '0';
len--;
}
if (len > 1 && name[len-1] == '^') {
name[len-1] = 0;
ret = get_parent(name, sha1, parent);
name[len-1] = '^';
if (!ret)
return 0;
}
ret = get_sha1(name, sha1);
if (!ret)
return 0;
return get_short_sha1(name, sha1);
}
static void show_default(void)
{
char *s = def;
if (s) {
unsigned char sha1[20];
def = NULL;
if (!get_extended_sha1(s, sha1)) {
show_rev(NORMAL, sha1);
return;
}
show_arg(s);
}
}
static int show_reference(const char *refname, const unsigned char *sha1)
{
show_rev(NORMAL, sha1);
return 0;
}
int main(int argc, char **argv)
{
int i, as_is = 0;
unsigned char sha1[20];
for (i = 1; i < argc; i++) {
char *arg = argv[i];
char *dotdot;
if (as_is) {
show_norev(arg);
continue;
}
if (*arg == '-') {
if (!strcmp(arg, "--")) {
show_default();
if (revs_only)
break;
as_is = 1;
}
if (!strcmp(arg, "--default")) {
def = argv[i+1];
i++;
continue;
}
if (!strcmp(arg, "--revs-only")) {
revs_only = 1;
continue;
}
if (!strcmp(arg, "--no-revs")) {
no_revs = 1;
continue;
}
if (!strcmp(arg, "--flags")) {
flags_only = 1;
continue;
}
if (!strcmp(arg, "--no-flags")) {
no_flags = 1;
continue;
}
if (!strcmp(arg, "--verify")) {
revs_only = 1;
do_rev_argument = 0;
single_rev = 1;
continue;
}
if (!strcmp(arg, "--sq")) {
output_sq = 1;
continue;
}
if (!strcmp(arg, "--not")) {
show_type ^= REVERSED;
continue;
}
if (!strcmp(arg, "--all")) {
for_each_ref(show_reference);
continue;
}
show_arg(arg);
continue;
}
dotdot = strstr(arg, "..");
if (dotdot) {
unsigned char end[20];
char *n = dotdot+2;
*dotdot = 0;
if (!get_extended_sha1(arg, sha1)) {
if (!*n)
n = "HEAD";
if (!get_extended_sha1(n, end)) {
if (no_revs)
continue;
def = NULL;
show_rev(NORMAL, end);
show_rev(REVERSED, sha1);
continue;
}
}
*dotdot = '.';
}
if (!get_extended_sha1(arg, sha1)) {
if (no_revs)
continue;
def = NULL;
show_rev(NORMAL, sha1);
continue;
}
if (*arg == '^' && !get_extended_sha1(arg+1, sha1)) {
if (no_revs)
continue;
def = NULL;
show_rev(REVERSED, sha1);
continue;
}
show_default();
show_norev(arg);
}
show_default();
if (single_rev && output_revs != 1) {
fprintf(stderr, "Needed a single revision\n");
exit(1);
}
return 0;
}