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(): _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500

DESCRIPTION

       The  mktemp()  function	generates a unique temporary filename from template.  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.

ERRORS

       EINVAL The last six characters of template were not XXXXXX.

CONFORMING TO

       4.3BSD, POSIX.1-2001.  POSIX.1-2008 removes the specification of mktemp().

NOTES

       The prototype is in <unistd.h> for libc4, libc5, glibc1; glibc2 follows the Single Unix Specification and has the prototype in <stdlib.h>.

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).

SEE ALSO

       mkstemp(3), tempnam(3), tmpfile(3), tmpnam(3)

COLOPHON

       This  page is part of release 3.25 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2008-08-06								 MKTEMP(3)