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 proto-
       type 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 testing 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)