incubator-nuttx/libc/stdio/lib_tmpnam.c

96 lines
3.9 KiB
C

/****************************************************************************
* libc/stdio/lib_tmpnam.c
*
* Copyright (C) 2014 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: tmpnam
*
* Description:
* The tmpnam() function generates a string that is a valid filename and
* that is not the same as the name of an existing file. The function is
* potentially capable of generating TMP_MAX different strings, but any or
* all of them may already be in use by existing files and thus not be
* suitable return values.
*
* The tmpnam() function generates a different string each time it is
* called from the same process, up to {TMP_MAX} times. If it is called
* more than {TMP_MAX} times, the behavior is implementation-defined.
*
* Returned Value:
* Upon successful completion, tmpnam() returns a pointer to a string. I
* no suitable string can be generated, the tmpnam() function will
* return a null pointer.
*
* If the argument s is a null pointer, tmpnam() will leave its result
* in an internal static object and return a pointer to that object.
* Subsequent calls to tmpnam() may modify the same object. If the
* argument s is not a null pointer, it is presumed to point to an
* array of at least L_tmpnam chars; tmpnam() will write its result in
* that array and will return the argument as its value.
*
****************************************************************************/
FAR char *tmpnam(FAR char *s)
{
static char path[L_tmpnam];
int ret;
if (s == NULL)
{
s = path;
}
(void)snprintf(s, L_tmpnam, "%s/XXXXXX.tmp", P_tmpdir);
ret = mktemp(s);
return (ret == OK) ? s : NULL;
}