xref: /illumos-gate/usr/src/man/man3c/mkstemp.3c (revision b6805bf78d2bbbeeaea8909a05623587b42d58b3)
te
Copyright (c) 2013, OmniTI Computer Consulting, Inc. All rights reserved.
Copyright (c) 1992, X/Open Company Limited. All Rights Reserved. Portions Copyright (c) 2006, Sun Microsystems, Inc. All Rights Reserved.
Sun Microsystems, Inc. gratefully acknowledges The Open Group for permission to reproduce portions of its copyrighted documentation. Original documentation from The Open Group can be obtained online at
http://www.opengroup.org/bookstore/.
The Institute of Electrical and Electronics Engineers and The Open Group, have given us permission to reprint portions of their documentation. In the following statement, the phrase "this text" refers to portions of the system documentation. Portions of this text are reprinted and reproduced in electronic form in the Sun OS Reference Manual, from IEEE Std 1003.1, 2004 Edition, Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2004 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any discrepancy between these versions and the original IEEE and The Open Group Standard, the original IEEE and The Open Group Standard is the referee document. The original Standard can be obtained online at http://www.opengroup.org/unix/online.html.
This notice shall appear on any product containing this material.
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
MKSTEMP 3C "Apr 19, 2013"
NAME
mkstemp, mkstemps, mkostemp, mkostemps, mkdtemp - make a unique file name from a template and open the file
SYNOPSIS

#include <stdlib.h>

int mkstemp(char *template);

int mkostemp(char *template, int flags);

int mkstemps(char *template, int slen);

int mkostemps(char *template, int slen, int flags);

char *mkdtemp(char *template);
DESCRIPTION

The mkstemp() function replaces the contents of the string pointed to by template by a unique file name, and returns a file descriptor for the file open for reading and writing. The function thus prevents any possible race condition between testing whether the file exists and opening it for use. The string in template should look like a file name with six trailing 'X's; mkstemp() replaces each 'X' with a character from the portable file name character set. The characters are chosen such that the resulting name does not duplicate the name of an existing file.

The mkstemps() function behaves the same as mkstemp(), except it permits a suffix to exist in the template. The template should be of the form /tmp/tmpXXXXXXsuffix. The slen parameter specifies the length of the suffix string.

The mkostemp() and mkostemps are like their mkstemp() and mkstemps() couterparts except that the flags argument is present and used to supplement (as a bitwise inclusive-OR) flags to internal open() calls. (e.g. O_SYNC, O_APPEND, and O_CLOEXEC).

The mkdtemp() function makes the same replacement to the template as in mktemp(3C) and creates the template directory using mkdir(2), passing a mode argument of 0700.

RETURN VALUES

Upon successful completion, mkstemp() returns an open file descriptor. Otherwise -1 is returned if no suitable file could be created.

ERRORS

The mkstemp(), mkstemps(), and mkdtemp() functions can set errno to the same values as lstat(2).

The mkstemp() and mkstemps() functions can set errno to the same values as open(2).

The mkdtemp() function can set errno to the same values as mkdir(2).

USAGE

It is possible to run out of letters.

The mkstemp() function does not check to determine whether the file name part of template exceeds the maximum allowable file name length.

The tmpfile(3C) function is preferred over this function.

The mkstemp() function is frequently used to create a temporary file that will be removed by the application before the application terminates.

The mkstemp() function has a transitional interface for 64-bit file offsets. See lf64(5).

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
Interface Stability See below.

The mkstemp() function is Standard. The mkstemps() and mkdtemp() functions are Stable.

SEE ALSO

getpid(2), lstat(2), mkdir(2), open(2), tmpfile(3C), mktemp(3C), attributes(5), lf64(5), standards(5)