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/* Copyright (C) 1991, 1992, 1996 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA. */
#include <string.h>
#include <errno.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
/* Generate a unique temporary file name from TEMPLATE.
The last six characters of TEMPLATE must be "XXXXXX";
they are replaced with a string that makes the filename unique.
Returns a file descriptor open on the file for reading and writing. */
int
mkstemp (template)
char *template;
{
static const char letters[]
= "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
size_t len;
size_t i;
len = strlen (template);
if (len < 6 || strcmp (&template[len - 6], "XXXXXX"))
{
__set_errno (EINVAL);
return -1;
}
if (sprintf (&template[len - 5], "%.5u",
(unsigned int) getpid () % 100000) != 5)
/* Inconceivable lossage. */
return -1;
for (i = 0; i < sizeof (letters); ++i)
{
int fd;
template[len - 6] = letters[i];
fd = open (template, O_RDWR|O_CREAT|O_EXCL, 0666);
if (fd >= 0)
return fd;
}
/* We return the null string if we can't find a unique file name. */
template[0] = '\0';
return -1;
}
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