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

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       project,    and    information    about    reporting    bugs,    can    be    found     at
       http://www.kernel.org/doc/man-pages/.