util-linux/lib/fileutils.c
Sami Kerola 6b79eb38ba lib: add fileutils function collection
The fileutils contains xmkstemp function will create temporary file
safe and reusable manner.

Reference: http://www.dwheeler.com/secure-programs/Secure-Programs-HOWTO.html#TEMPORARY-FILES
CC: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
2012-03-18 14:28:04 +01:00

55 lines
993 B
C

/*
* Copyright (C) 2012 Sami Kerola <kerolasa@iki.fi>
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <unistd.h>
#include "c.h"
#include "pathnames.h"
/* Create open temporary file in safe way. Please notice that the
* file permissions are -rw------- by default. */
FILE *xmkstemp(char **tmpname)
{
char *localtmp;
char *tmpenv;
mode_t old_mode;
int fd;
FILE *ret;
tmpenv = getenv("TMPDIR");
if (tmpenv)
asprintf(&localtmp, "%s/%s.XXXXXX", tmpenv,
program_invocation_short_name);
else
asprintf(&localtmp, "%s/%s.XXXXXX", _PATH_TMP,
program_invocation_short_name);
old_mode = umask(077);
fd = mkstemp(localtmp);
umask(old_mode);
if (fd == -1)
return NULL;
if (!(ret = fdopen(fd, "w+")))
goto err;
*tmpname = localtmp;
return ret;
err:
close(fd);
return NULL;
}
#ifdef TEST_PROGRAM
int main(void)
{
FILE *f;
char *tmpname;
f = xmkstemp(&tmpname);
unlink(tmpname);
free(tmpname);
fclose(f);
return EXIT_FAILURE;
}
#endif