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/*
* Copyright © 2015 Collabora, Ltd.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice (including the
* next paragraph) shall be included in all copies or substantial
* portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "config.h"
#include <stdio.h>
#include <errno.h>
#include <time.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "file-util.h"
static int
current_time_str(char *str, size_t len, const char *fmt)
{
time_t t;
struct tm *t_local;
int ret;
t = time(NULL);
t_local = localtime(&t);
if (!t_local) {
errno = ETIME;
return -1;
}
ret = strftime(str, len, fmt, t_local);
if (ret == 0) {
errno = ETIME;
return -1;
}
return ret;
}
static int
create_file_excl(const char *fname)
{
return open(fname, O_RDWR | O_CLOEXEC | O_CREAT | O_EXCL, 00666);
}
/** Create a unique file with date and time in the name
*
* \param path_prefix Path and file name prefix.
* \param suffix File name suffix.
* \param name_out[out] Buffer for the resulting file name.
* \param name_len Number of bytes usable in name_out.
* \return stdio FILE pointer, or NULL on failure.
*
* Create and open a new file with the name concatenated from
* path_prefix, date and time, and suffix. If a file with this name
* already exists, an counter number is added to the end of the
* date and time sub-string. The counter is increased until a free file
* name is found.
*
* Once creating the file succeeds, the name of the file is in name_out.
* On failure, the contents of name_out are undefined and errno is set.
*/
FILE *
file_create_dated(const char *path_prefix, const char *suffix,
char *name_out, size_t name_len)
{
char timestr[128];
int ret;
int fd;
int cnt = 0;
if (current_time_str(timestr, sizeof(timestr), "%F_%H-%M-%S") < 0)
return NULL;
ret = snprintf(name_out, name_len, "%s%s%s",
path_prefix, timestr, suffix);
if (ret < 0 || (size_t)ret >= name_len) {
errno = ENOBUFS;
return NULL;
}
fd = create_file_excl(name_out);
while (fd == -1 && errno == EEXIST) {
cnt++;
ret = snprintf(name_out, name_len, "%s%s-%d%s",
path_prefix, timestr, cnt, suffix);
if (ret < 0 || (size_t)ret >= name_len) {
errno = ENOBUFS;
return NULL;
}
fd = create_file_excl(name_out);
}
if (fd == -1)
return NULL;
return fdopen(fd, "w");
}
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