[thirdparty/git.git] / wrapper.c

/*
 * Various trivial helper wrappers around standard functions
 */
#include "cache.h"

static void do_nothing(size_t size)
{
}

static void (*try_to_free_routine)(size_t size) = do_nothing;

static void memory_limit_check(size_t size)
{
	static int limit = -1;
	if (limit == -1) {
		const char *env = getenv("GIT_ALLOC_LIMIT");
		limit = env ? atoi(env) * 1024 : 0;
	}
	if (limit && size > limit)
		die("attempting to allocate %"PRIuMAX" over limit %d",
		    (intmax_t)size, limit);
}

try_to_free_t set_try_to_free_routine(try_to_free_t routine)
{
	try_to_free_t old = try_to_free_routine;
	if (!routine)
		routine = do_nothing;
	try_to_free_routine = routine;
	return old;
}

char *xstrdup(const char *str)
{
	char *ret = strdup(str);
	if (!ret) {
		try_to_free_routine(strlen(str) + 1);
		ret = strdup(str);
		if (!ret)
			die("Out of memory, strdup failed");
	}
	return ret;
}

void *xmalloc(size_t size)
{
	void *ret;

	memory_limit_check(size);
	ret = malloc(size);
	if (!ret && !size)
		ret = malloc(1);
	if (!ret) {
		try_to_free_routine(size);
		ret = malloc(size);
		if (!ret && !size)
			ret = malloc(1);
		if (!ret)
			die("Out of memory, malloc failed (tried to allocate %lu bytes)",
			    (unsigned long)size);
	}
#ifdef XMALLOC_POISON
	memset(ret, 0xA5, size);
#endif
	return ret;
}

void *xmallocz(size_t size)
{
	void *ret;
	if (unsigned_add_overflows(size, 1))
		die("Data too large to fit into virtual memory space.");
	ret = xmalloc(size + 1);
	((char*)ret)[size] = 0;
	return ret;
}

/*
 * xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
 * "data" to the allocated memory, zero terminates the allocated memory,
 * and returns a pointer to the allocated memory. If the allocation fails,
 * the program dies.
 */
void *xmemdupz(const void *data, size_t len)
{
	return memcpy(xmallocz(len), data, len);
}

char *xstrndup(const char *str, size_t len)
{
	char *p = memchr(str, '\0', len);
	return xmemdupz(str, p ? p - str : len);
}

void *xrealloc(void *ptr, size_t size)
{
	void *ret;

	memory_limit_check(size);
	ret = realloc(ptr, size);
	if (!ret && !size)
		ret = realloc(ptr, 1);
	if (!ret) {
		try_to_free_routine(size);
		ret = realloc(ptr, size);
		if (!ret && !size)
			ret = realloc(ptr, 1);
		if (!ret)
			die("Out of memory, realloc failed");
	}
	return ret;
}

void *xcalloc(size_t nmemb, size_t size)
{
	void *ret;

	memory_limit_check(size * nmemb);
	ret = calloc(nmemb, size);
	if (!ret && (!nmemb || !size))
		ret = calloc(1, 1);
	if (!ret) {
		try_to_free_routine(nmemb * size);
		ret = calloc(nmemb, size);
		if (!ret && (!nmemb || !size))
			ret = calloc(1, 1);
		if (!ret)
			die("Out of memory, calloc failed");
	}
	return ret;
}

/*
 * Limit size of IO chunks, because huge chunks only cause pain.  OS X
 * 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
 * the absence of bugs, large chunks can result in bad latencies when
 * you decide to kill the process.
 */
#define MAX_IO_SIZE (8*1024*1024)

/*
 * xread() is the same a read(), but it automatically restarts read()
 * operations with a recoverable error (EAGAIN and EINTR). xread()
 * DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
 */
ssize_t xread(int fd, void *buf, size_t len)
{
	ssize_t nr;
	if (len > MAX_IO_SIZE)
	    len = MAX_IO_SIZE;
	while (1) {
		nr = read(fd, buf, len);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

/*
 * xwrite() is the same a write(), but it automatically restarts write()
 * operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
 * GUARANTEE that "len" bytes is written even if the operation is successful.
 */
ssize_t xwrite(int fd, const void *buf, size_t len)
{
	ssize_t nr;
	if (len > MAX_IO_SIZE)
	    len = MAX_IO_SIZE;
	while (1) {
		nr = write(fd, buf, len);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

/*
 * xpread() is the same as pread(), but it automatically restarts pread()
 * operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
 * NOT GUARANTEE that "len" bytes is read even if the data is available.
 */
ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
{
	ssize_t nr;
	if (len > MAX_IO_SIZE)
		len = MAX_IO_SIZE;
	while (1) {
		nr = pread(fd, buf, len, offset);
		if ((nr < 0) && (errno == EAGAIN || errno == EINTR))
			continue;
		return nr;
	}
}

ssize_t read_in_full(int fd, void *buf, size_t count)
{
	char *p = buf;
	ssize_t total = 0;

	while (count > 0) {
		ssize_t loaded = xread(fd, p, count);
		if (loaded < 0)
			return -1;
		if (loaded == 0)
			return total;
		count -= loaded;
		p += loaded;
		total += loaded;
	}

	return total;
}

ssize_t write_in_full(int fd, const void *buf, size_t count)
{
	const char *p = buf;
	ssize_t total = 0;

	while (count > 0) {
		ssize_t written = xwrite(fd, p, count);
		if (written < 0)
			return -1;
		if (!written) {
			errno = ENOSPC;
			return -1;
		}
		count -= written;
		p += written;
		total += written;
	}

	return total;
}

ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
{
	char *p = buf;
	ssize_t total = 0;

	while (count > 0) {
		ssize_t loaded = xpread(fd, p, count, offset);
		if (loaded < 0)
			return -1;
		if (loaded == 0)
			return total;
		count -= loaded;
		p += loaded;
		total += loaded;
		offset += loaded;
	}

	return total;
}

int xdup(int fd)
{
	int ret = dup(fd);
	if (ret < 0)
		die_errno("dup failed");
	return ret;
}

FILE *xfdopen(int fd, const char *mode)
{
	FILE *stream = fdopen(fd, mode);
	if (stream == NULL)
		die_errno("Out of memory? fdopen failed");
	return stream;
}

int xmkstemp(char *template)
{
	int fd;
	char origtemplate[PATH_MAX];
	strlcpy(origtemplate, template, sizeof(origtemplate));

	fd = mkstemp(template);
	if (fd < 0) {
		int saved_errno = errno;
		const char *nonrelative_template;

		if (strlen(template) != strlen(origtemplate))
			template = origtemplate;

		nonrelative_template = absolute_path(template);
		errno = saved_errno;
		die_errno("Unable to create temporary file '%s'",
			nonrelative_template);
	}
	return fd;
}

/* git_mkstemp() - create tmp file honoring TMPDIR variable */
int git_mkstemp(char *path, size_t len, const char *template)
{
	const char *tmp;
	size_t n;

	tmp = getenv("TMPDIR");
	if (!tmp)
		tmp = "/tmp";
	n = snprintf(path, len, "%s/%s", tmp, template);
	if (len <= n) {
		errno = ENAMETOOLONG;
		return -1;
	}
	return mkstemp(path);
}

/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
int git_mkstemps(char *path, size_t len, const char *template, int suffix_len)
{
	const char *tmp;
	size_t n;

	tmp = getenv("TMPDIR");
	if (!tmp)
		tmp = "/tmp";
	n = snprintf(path, len, "%s/%s", tmp, template);
	if (len <= n) {
		errno = ENAMETOOLONG;
		return -1;
	}
	return mkstemps(path, suffix_len);
}

/* Adapted from libiberty's mkstemp.c. */

#undef TMP_MAX
#define TMP_MAX 16384

int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
{
	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, mode);
		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';
	return -1;
}

int git_mkstemp_mode(char *pattern, int mode)
{
	/* mkstemp is just mkstemps with no suffix */
	return git_mkstemps_mode(pattern, 0, mode);
}

#ifdef NO_MKSTEMPS
int gitmkstemps(char *pattern, int suffix_len)
{
	return git_mkstemps_mode(pattern, suffix_len, 0600);
}
#endif

int xmkstemp_mode(char *template, int mode)
{
	int fd;
	char origtemplate[PATH_MAX];
	strlcpy(origtemplate, template, sizeof(origtemplate));

	fd = git_mkstemp_mode(template, mode);
	if (fd < 0) {
		int saved_errno = errno;
		const char *nonrelative_template;

		if (!template[0])
			template = origtemplate;

		nonrelative_template = absolute_path(template);
		errno = saved_errno;
		die_errno("Unable to create temporary file '%s'",
			nonrelative_template);
	}
	return fd;
}

static int warn_if_unremovable(const char *op, const char *file, int rc)
{
	if (rc < 0) {
		int err = errno;
		if (ENOENT != err) {
			warning("unable to %s %s: %s",
				op, file, strerror(errno));
			errno = err;
		}
	}
	return rc;
}

int unlink_or_warn(const char *file)
{
	return warn_if_unremovable("unlink", file, unlink(file));
}

int rmdir_or_warn(const char *file)
{
	return warn_if_unremovable("rmdir", file, rmdir(file));
}

int remove_or_warn(unsigned int mode, const char *file)
{
	return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
}

void warn_on_inaccessible(const char *path)
{
	warning(_("unable to access '%s': %s"), path, strerror(errno));
}

static int access_error_is_ok(int err, unsigned flag)
{
	return err == ENOENT || err == ENOTDIR ||
		((flag & ACCESS_EACCES_OK) && err == EACCES);
}

int access_or_warn(const char *path, int mode, unsigned flag)
{
	int ret = access(path, mode);
	if (ret && !access_error_is_ok(errno, flag))
		warn_on_inaccessible(path);
	return ret;
}

int access_or_die(const char *path, int mode, unsigned flag)
{
	int ret = access(path, mode);
	if (ret && !access_error_is_ok(errno, flag))
		die_errno(_("unable to access '%s'"), path);
	return ret;
}

struct passwd *xgetpwuid_self(void)
{
	struct passwd *pw;

	errno = 0;
	pw = getpwuid(getuid());
	if (!pw)
		die(_("unable to look up current user in the passwd file: %s"),
		    errno ? strerror(errno) : _("no such user"));
	return pw;
}
Commit	Line	Data
112db553 LT	1	/*
	2	* Various trivial helper wrappers around standard functions
	3	*/
	4	#include "cache.h"
	5
e0500293	6	static void do_nothing(size_t size)
a9a74636	7	{
a9a74636 NP	8	}
a9a74636 NP	9
e0500293	10	static void (*try_to_free_routine)(size_t size) = do_nothing;
a9a74636	11
d41489a6 NTND	12	static void memory_limit_check(size_t size)
	13	{
	14	static int limit = -1;
	15	if (limit == -1) {
	16	const char *env = getenv("GIT_ALLOC_LIMIT");
	17	limit = env ? atoi(env) * 1024 : 0;
	18	}
	19	if (limit && size > limit)
	20	die("attempting to allocate %"PRIuMAX" over limit %d",
	21	(intmax_t)size, limit);
	22	}
	23
851c34b0	24	try_to_free_t set_try_to_free_routine(try_to_free_t routine)
a9a74636	25	{
851c34b0	26	try_to_free_t old = try_to_free_routine;
00b0d7f7 JH	27	if (!routine)
00b0d7f7 JH	28	routine = do_nothing;
851c34b0 JS	29	try_to_free_routine = routine;
851c34b0 JS	30	return old;
a9a74636 NP	31	}
a9a74636 NP	32
112db553 LT	33	char xstrdup(const char str)
	34	{
	35	char *ret = strdup(str);
	36	if (!ret) {
a9a74636	37	try_to_free_routine(strlen(str) + 1);
112db553 LT	38	ret = strdup(str);
	39	if (!ret)
	40	die("Out of memory, strdup failed");
	41	}
	42	return ret;
	43	}
	44
	45	void *xmalloc(size_t size)
	46	{
d41489a6 NTND	47	void *ret;
	48
	49	memory_limit_check(size);
	50	ret = malloc(size);
112db553 LT	51	if (!ret && !size)
	52	ret = malloc(1);
	53	if (!ret) {
a9a74636	54	try_to_free_routine(size);
112db553 LT	55	ret = malloc(size);
	56	if (!ret && !size)
	57	ret = malloc(1);
	58	if (!ret)
8bd9fd50 MM	59	die("Out of memory, malloc failed (tried to allocate %lu bytes)",
8bd9fd50 MM	60	(unsigned long)size);
112db553 LT	61	}
	62	#ifdef XMALLOC_POISON
	63	memset(ret, 0xA5, size);
	64	#endif
	65	return ret;
	66	}
	67
5bf9219d IL	68	void *xmallocz(size_t size)
	69	{
	70	void *ret;
1368f650	71	if (unsigned_add_overflows(size, 1))
5bf9219d IL	72	die("Data too large to fit into virtual memory space.");
	73	ret = xmalloc(size + 1);
	74	((char*)ret)[size] = 0;
	75	return ret;
	76	}
	77
112db553 LT	78	/*
	79	* xmemdupz() allocates (len + 1) bytes of memory, duplicates "len" bytes of
	80	* "data" to the allocated memory, zero terminates the allocated memory,
	81	* and returns a pointer to the allocated memory. If the allocation fails,
	82	* the program dies.
	83	*/
	84	void xmemdupz(const void data, size_t len)
	85	{
5bf9219d	86	return memcpy(xmallocz(len), data, len);
112db553 LT	87	}
	88
	89	char xstrndup(const char str, size_t len)
	90	{
	91	char *p = memchr(str, '\0', len);
	92	return xmemdupz(str, p ? p - str : len);
	93	}
	94
	95	void xrealloc(void ptr, size_t size)
	96	{
d41489a6 NTND	97	void *ret;
	98
	99	memory_limit_check(size);
	100	ret = realloc(ptr, size);
112db553 LT	101	if (!ret && !size)
	102	ret = realloc(ptr, 1);
	103	if (!ret) {
a9a74636	104	try_to_free_routine(size);
112db553 LT	105	ret = realloc(ptr, size);
	106	if (!ret && !size)
	107	ret = realloc(ptr, 1);
	108	if (!ret)
	109	die("Out of memory, realloc failed");
	110	}
	111	return ret;
	112	}
	113
	114	void *xcalloc(size_t nmemb, size_t size)
	115	{
d41489a6 NTND	116	void *ret;
	117
	118	memory_limit_check(size * nmemb);
	119	ret = calloc(nmemb, size);
112db553 LT	120	if (!ret && (!nmemb \|\| !size))
	121	ret = calloc(1, 1);
	122	if (!ret) {
a9a74636	123	try_to_free_routine(nmemb * size);
112db553 LT	124	ret = calloc(nmemb, size);
	125	if (!ret && (!nmemb \|\| !size))
	126	ret = calloc(1, 1);
	127	if (!ret)
	128	die("Out of memory, calloc failed");
	129	}
	130	return ret;
	131	}
	132
0b6806b9 SP	133	/*
	134	* Limit size of IO chunks, because huge chunks only cause pain. OS X
	135	* 64-bit is buggy, returning EINVAL if len >= INT_MAX; and even in
382d20e3	136	* the absence of bugs, large chunks can result in bad latencies when
0b6806b9 SP	137	* you decide to kill the process.
	138	*/
	139	#define MAX_IO_SIZE (810241024)
	140
112db553 LT	141	/*
	142	* xread() is the same a read(), but it automatically restarts read()
	143	* operations with a recoverable error (EAGAIN and EINTR). xread()
	144	* DOES NOT GUARANTEE that "len" bytes is read even if the data is available.
	145	*/
	146	ssize_t xread(int fd, void *buf, size_t len)
	147	{
	148	ssize_t nr;
0b6806b9 SP	149	if (len > MAX_IO_SIZE)
0b6806b9 SP	150	len = MAX_IO_SIZE;
112db553 LT	151	while (1) {
	152	nr = read(fd, buf, len);
	153	if ((nr < 0) && (errno == EAGAIN \|\| errno == EINTR))
	154	continue;
	155	return nr;
	156	}
	157	}
	158
	159	/*
	160	* xwrite() is the same a write(), but it automatically restarts write()
	161	* operations with a recoverable error (EAGAIN and EINTR). xwrite() DOES NOT
	162	* GUARANTEE that "len" bytes is written even if the operation is successful.
	163	*/
	164	ssize_t xwrite(int fd, const void *buf, size_t len)
	165	{
	166	ssize_t nr;
0b6806b9 SP	167	if (len > MAX_IO_SIZE)
0b6806b9 SP	168	len = MAX_IO_SIZE;
112db553 LT	169	while (1) {
	170	nr = write(fd, buf, len);
	171	if ((nr < 0) && (errno == EAGAIN \|\| errno == EINTR))
9aa91af0 YM	172	continue;
	173	return nr;
	174	}
	175	}
	176
	177	/*
	178	* xpread() is the same as pread(), but it automatically restarts pread()
	179	* operations with a recoverable error (EAGAIN and EINTR). xpread() DOES
	180	* NOT GUARANTEE that "len" bytes is read even if the data is available.
	181	*/
	182	ssize_t xpread(int fd, void *buf, size_t len, off_t offset)
	183	{
	184	ssize_t nr;
	185	if (len > MAX_IO_SIZE)
	186	len = MAX_IO_SIZE;
	187	while (1) {
	188	nr = pread(fd, buf, len, offset);
	189	if ((nr < 0) && (errno == EAGAIN \|\| errno == EINTR))
112db553 LT	190	continue;
	191	return nr;
	192	}
	193	}
	194
559e840b JH	195	ssize_t read_in_full(int fd, void *buf, size_t count)
	196	{
	197	char *p = buf;
	198	ssize_t total = 0;
	199
	200	while (count > 0) {
	201	ssize_t loaded = xread(fd, p, count);
56d7c27a JK	202	if (loaded < 0)
	203	return -1;
	204	if (loaded == 0)
	205	return total;
559e840b JH	206	count -= loaded;
	207	p += loaded;
	208	total += loaded;
	209	}
	210
	211	return total;
	212	}
	213
	214	ssize_t write_in_full(int fd, const void *buf, size_t count)
	215	{
	216	const char *p = buf;
	217	ssize_t total = 0;
	218
	219	while (count > 0) {
	220	ssize_t written = xwrite(fd, p, count);
	221	if (written < 0)
	222	return -1;
	223	if (!written) {
	224	errno = ENOSPC;
	225	return -1;
	226	}
	227	count -= written;
	228	p += written;
	229	total += written;
	230	}
	231
	232	return total;
	233	}
	234
426ddeea YM	235	ssize_t pread_in_full(int fd, void *buf, size_t count, off_t offset)
	236	{
	237	char *p = buf;
	238	ssize_t total = 0;
	239
	240	while (count > 0) {
	241	ssize_t loaded = xpread(fd, p, count, offset);
	242	if (loaded < 0)
	243	return -1;
	244	if (loaded == 0)
	245	return total;
	246	count -= loaded;
	247	p += loaded;
	248	total += loaded;
	249	offset += loaded;
	250	}
	251
	252	return total;
	253	}
	254
112db553 LT	255	int xdup(int fd)
	256	{
	257	int ret = dup(fd);
	258	if (ret < 0)
d824cbba	259	die_errno("dup failed");
112db553 LT	260	return ret;
	261	}
	262
	263	FILE xfdopen(int fd, const char mode)
	264	{
	265	FILE *stream = fdopen(fd, mode);
	266	if (stream == NULL)
d824cbba	267	die_errno("Out of memory? fdopen failed");
112db553 LT	268	return stream;
	269	}
	270
	271	int xmkstemp(char *template)
	272	{
	273	int fd;
6cf6bb3e AE	274	char origtemplate[PATH_MAX];
6cf6bb3e AE	275	strlcpy(origtemplate, template, sizeof(origtemplate));
112db553 LT	276
112db553 LT	277	fd = mkstemp(template);
6cf6bb3e AE	278	if (fd < 0) {
	279	int saved_errno = errno;
	280	const char *nonrelative_template;
	281
f7be59b4	282	if (strlen(template) != strlen(origtemplate))
6cf6bb3e AE	283	template = origtemplate;
6cf6bb3e AE	284
e2a57aac	285	nonrelative_template = absolute_path(template);
6cf6bb3e AE	286	errno = saved_errno;
	287	die_errno("Unable to create temporary file '%s'",
	288	nonrelative_template);
	289	}
112db553 LT	290	return fd;
112db553 LT	291	}
39c68542	292
33f23936 JN	293	/* git_mkstemp() - create tmp file honoring TMPDIR variable */
	294	int git_mkstemp(char path, size_t len, const char template)
	295	{
	296	const char *tmp;
	297	size_t n;
	298
	299	tmp = getenv("TMPDIR");
	300	if (!tmp)
	301	tmp = "/tmp";
	302	n = snprintf(path, len, "%s/%s", tmp, template);
	303	if (len <= n) {
	304	errno = ENAMETOOLONG;
	305	return -1;
	306	}
	307	return mkstemp(path);
	308	}
	309
	310	/* git_mkstemps() - create tmp file with suffix honoring TMPDIR variable. */
	311	int git_mkstemps(char path, size_t len, const char template, int suffix_len)
	312	{
	313	const char *tmp;
	314	size_t n;
	315
	316	tmp = getenv("TMPDIR");
	317	if (!tmp)
	318	tmp = "/tmp";
	319	n = snprintf(path, len, "%s/%s", tmp, template);
	320	if (len <= n) {
	321	errno = ENAMETOOLONG;
	322	return -1;
	323	}
	324	return mkstemps(path, suffix_len);
	325	}
	326
	327	/* Adapted from libiberty's mkstemp.c. */
	328
	329	#undef TMP_MAX
	330	#define TMP_MAX 16384
	331
	332	int git_mkstemps_mode(char *pattern, int suffix_len, int mode)
	333	{
	334	static const char letters[] =
	335	"abcdefghijklmnopqrstuvwxyz"
	336	"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
	337	"0123456789";
	338	static const int num_letters = 62;
	339	uint64_t value;
	340	struct timeval tv;
	341	char *template;
	342	size_t len;
	343	int fd, count;
	344
	345	len = strlen(pattern);
	346
	347	if (len < 6 + suffix_len) {
	348	errno = EINVAL;
	349	return -1;
	350	}
	351
	352	if (strncmp(&pattern[len - 6 - suffix_len], "XXXXXX", 6)) {
	353	errno = EINVAL;
	354	return -1;
	355	}
	356
357	/*
358	* Replace pattern's XXXXXX characters with randomness.
359	* Try TMP_MAX different filenames.
360	*/
361	gettimeofday(&tv, NULL);
362	value = ((size_t)(tv.tv_usec << 16)) ^ tv.tv_sec ^ getpid();
363	template = &pattern[len - 6 - suffix_len];
364	for (count = 0; count < TMP_MAX; ++count) {
365	uint64_t v = value;
366	/* Fill in the random bits. */
367	template[0] = letters[v % num_letters]; v /= num_letters;
368	template[1] = letters[v % num_letters]; v /= num_letters;
369	template[2] = letters[v % num_letters]; v /= num_letters;
370	template[3] = letters[v % num_letters]; v /= num_letters;
371	template[4] = letters[v % num_letters]; v /= num_letters;
372	template[5] = letters[v % num_letters]; v /= num_letters;
373
374	fd = open(pattern, O_CREAT \| O_EXCL \| O_RDWR, mode);
a2cb86c1	375	if (fd >= 0)
33f23936 JN	376	return fd;
	377	/*
	378	* Fatal error (EPERM, ENOSPC etc).
	379	* It doesn't make sense to loop.
	380	*/
	381	if (errno != EEXIST)
	382	break;
	383	/*
	384	* This is a random value. It is only necessary that
	385	* the next TMP_MAX values generated by adding 7777 to
	386	* VALUE are different with (module 2^32).
	387	*/
	388	value += 7777;
	389	}
	390	/* We return the null string if we can't find a unique file name. */
	391	pattern[0] = '\0';
	392	return -1;
	393	}
	394
	395	int git_mkstemp_mode(char *pattern, int mode)
	396	{
	397	/* mkstemp is just mkstemps with no suffix */
	398	return git_mkstemps_mode(pattern, 0, mode);
	399	}
	400
ec145c9c	401	#ifdef NO_MKSTEMPS
33f23936 JN	402	int gitmkstemps(char *pattern, int suffix_len)
	403	{
	404	return git_mkstemps_mode(pattern, suffix_len, 0600);
	405	}
ec145c9c	406	#endif
33f23936	407
b862b61c MM	408	int xmkstemp_mode(char *template, int mode)
	409	{
	410	int fd;
6cf6bb3e AE	411	char origtemplate[PATH_MAX];
6cf6bb3e AE	412	strlcpy(origtemplate, template, sizeof(origtemplate));
b862b61c MM	413
b862b61c MM	414	fd = git_mkstemp_mode(template, mode);
6cf6bb3e AE	415	if (fd < 0) {
	416	int saved_errno = errno;
	417	const char *nonrelative_template;
	418
	419	if (!template[0])
	420	template = origtemplate;
	421
e2a57aac	422	nonrelative_template = absolute_path(template);
6cf6bb3e AE	423	errno = saved_errno;
	424	die_errno("Unable to create temporary file '%s'",
	425	nonrelative_template);
	426	}
b862b61c MM	427	return fd;
	428	}
	429
10e13ec8	430	static int warn_if_unremovable(const char op, const char file, int rc)
fc71db39	431	{
fc71db39 AR	432	if (rc < 0) {
	433	int err = errno;
	434	if (ENOENT != err) {
10e13ec8 PC	435	warning("unable to %s %s: %s",
10e13ec8 PC	436	op, file, strerror(errno));
fc71db39 AR	437	errno = err;
	438	}
	439	}
	440	return rc;
	441	}
	442
10e13ec8 PC	443	int unlink_or_warn(const char *file)
	444	{
	445	return warn_if_unremovable("unlink", file, unlink(file));
	446	}
d1723296 PC	447
	448	int rmdir_or_warn(const char *file)
	449	{
	450	return warn_if_unremovable("rmdir", file, rmdir(file));
	451	}
80d706af PC	452
	453	int remove_or_warn(unsigned int mode, const char *file)
	454	{
	455	return S_ISGITLINK(mode) ? rmdir_or_warn(file) : unlink_or_warn(file);
	456	}
2f705875	457
55b38a48 JH	458	void warn_on_inaccessible(const char *path)
	459	{
	460	warning(_("unable to access '%s': %s"), path, strerror(errno));
	461	}
	462
4698c8fe JN	463	static int access_error_is_ok(int err, unsigned flag)
	464	{
	465	return err == ENOENT \|\| err == ENOTDIR \|\|
	466	((flag & ACCESS_EACCES_OK) && err == EACCES);
	467	}
	468
	469	int access_or_warn(const char *path, int mode, unsigned flag)
ba8bd830 JK	470	{
ba8bd830 JK	471	int ret = access(path, mode);
4698c8fe	472	if (ret && !access_error_is_ok(errno, flag))
55b38a48	473	warn_on_inaccessible(path);
ba8bd830 JK	474	return ret;
	475	}
	476
4698c8fe	477	int access_or_die(const char *path, int mode, unsigned flag)
96b9e0e3 JN	478	{
96b9e0e3 JN	479	int ret = access(path, mode);
4698c8fe	480	if (ret && !access_error_is_ok(errno, flag))
96b9e0e3 JN	481	die_errno(_("unable to access '%s'"), path);
	482	return ret;
	483	}
	484
2f705875 JK	485	struct passwd *xgetpwuid_self(void)
	486	{
	487	struct passwd *pw;
	488
	489	errno = 0;
	490	pw = getpwuid(getuid());
	491	if (!pw)
	492	die(_("unable to look up current user in the passwd file: %s"),
	493	errno ? strerror(errno) : _("no such user"));
	494	return pw;
	495	}