MKTEMP(3)		   Linux Programmer's Manual		     MKTEMP(3)



NAME
       mktemp - make a unique temporary filename

SYNOPSIS
       #include <stdlib.h>

       char *mktemp(char *template);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       mktemp():
	   Since glibc 2.12:
	       (_XOPEN_SOURCE >= 500) && ! (_POSIX_C_SOURCE >= 200112L)
		   || /* Glibc since 2.19: */ _DEFAULT_SOURCE
		   || /* Glibc <= 2.19: */ _SVID_SOURCE || _BSD_SOURCE
	   Before glibc 2.12:
	       _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500

DESCRIPTION
       Never use this function; see BUGS.

       The  mktemp()  function generates a unique temporary filename from tem-
       plate.  The last six characters of template must be  XXXXXX  and	 these
       are  replaced  with  a string that makes the filename unique.  Since it
       will be modified, template must not be a string constant, but should be
       declared as a character array.

RETURN VALUE
       The  mktemp()  function	always returns template.  If a unique name was
       created, the last six bytes of template will have been modified in such
       a  way that the resulting name is unique (i.e., does not exist already)
       If a unique name could not  be  created,	 template  is  made  an	 empty
       string, and errno is set to indicate the error.

ERRORS
       EINVAL The last six characters of template were not XXXXXX.

ATTRIBUTES
       For   an	  explanation	of   the  terms	 used  in  this	 section,  see
       attributes(7).

       +----------+---------------+---------+
       |Interface | Attribute	  | Value   |
       +----------+---------------+---------+
       |mktemp()  | Thread safety | MT-Safe |
       +----------+---------------+---------+
CONFORMING TO
       4.3BSD,	POSIX.1-2001.	POSIX.1-2008  removes  the  specification   of
       mktemp().

BUGS
       Never  use  mktemp().   Some  implementations follow 4.3BSD and replace
       XXXXXX by the current process ID and a single letter, so that  at  most
       26  different  names  can be returned.  Since on the one hand the names
       are easy to guess, and on the other hand there is a race between	 test-
       ing whether the name exists and opening the file, every use of mktemp()
       is a security risk.  The race is avoided by mkstemp(3) and mkdtemp(3).

SEE ALSO
       mktemp(1), mkdtemp(3), mkstemp(3), tempnam(3), tmpfile(3), tmpnam(3)

COLOPHON
       This page is part of release 4.10 of the Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       https://www.kernel.org/doc/man-pages/.



GNU				  2016-07-17			     MKTEMP(3)