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:
               _BSD_SOURCE || _SVID_SOURCE ||
                   (_XOPEN_SOURCE >= 500 ||
                        _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) &&
                   !(_POSIX_C_SOURCE >= 200112L || _XOPEN_SOURCE >= 600)
           Before glibc 2.12:
               _BSD_SOURCE || _SVID_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED

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, and errno is set to
       indicate the error.

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 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 3.54 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/.