0620b39b3b
mkstemps() is a BSD extension so provide an implementation for cross-platform use. Signed-off-by: David Aguilar <davvid@gmail.com> Tested-by: Johannes Sixt <j6t@kdbg.org> (Windows) Signed-off-by: Junio C Hamano <gitster@pobox.com>
71 lines
1.7 KiB
C
71 lines
1.7 KiB
C
#include "../git-compat-util.h"
|
|
|
|
/* Adapted from libiberty's mkstemp.c. */
|
|
|
|
#undef TMP_MAX
|
|
#define TMP_MAX 16384
|
|
|
|
int gitmkstemps(char *pattern, int suffix_len)
|
|
{
|
|
static const char letters[] =
|
|
"abcdefghijklmnopqrstuvwxyz"
|
|
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
|
|
"0123456789";
|
|
static const int num_letters = 62;
|
|
uint64_t value;
|
|
struct timeval tv;
|
|
char *template;
|
|
size_t len;
|
|
int fd, count;
|
|
|
|
len = strlen(pattern);
|
|
|
|
if (len < 6 + suffix_len) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|
|
|
|
/*
|
|
* Replace pattern's XXXXXX characters with randomness.
|
|
* Try TMP_MAX different filenames.
|
|
*/
|
|
gettimeofday(&tv, NULL);
|
|
value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
|
|
template = &pattern[len - 6 - suffix_len];
|
|
for (count = 0; count < TMP_MAX; ++count) {
|
|
uint64_t v = value;
|
|
/* Fill in the random bits. */
|
|
template[0] = letters[v % num_letters]; v /= num_letters;
|
|
template[1] = letters[v % num_letters]; v /= num_letters;
|
|
template[2] = letters[v % num_letters]; v /= num_letters;
|
|
template[3] = letters[v % num_letters]; v /= num_letters;
|
|
template[4] = letters[v % num_letters]; v /= num_letters;
|
|
template[5] = letters[v % num_letters]; v /= num_letters;
|
|
|
|
fd = open(pattern, O_CREAT | O_EXCL | O_RDWR, 0600);
|
|
if (fd > 0)
|
|
return fd;
|
|
/*
|
|
* Fatal error (EPERM, ENOSPC etc).
|
|
* It doesn't make sense to loop.
|
|
*/
|
|
if (errno != EEXIST)
|
|
break;
|
|
/*
|
|
* This is a random value. It is only necessary that
|
|
* the next TMP_MAX values generated by adding 7777 to
|
|
* VALUE are different with (module 2^32).
|
|
*/
|
|
value += 7777;
|
|
}
|
|
/* We return the null string if we can't find a unique file name. */
|
|
pattern[0] = '\0';
|
|
errno = EINVAL;
|
|
return -1;
|
|
}
|