redhat man page for mkstemp

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

NAME
       mkstemp - create a unique temporary file

SYNOPSIS
       #include <stdlib.h>

       int mkstemp(char *template);

DESCRIPTION
       The  mkstemp() function generates a unique temporary file name from template.  The last six characters of template must be XXXXXX and these
       are replaced with a string that makes the filename unique. The file is then created with mode read/write and permissions 0666 (glibc  2.0.6
       and earlier), 0600 (glibc 2.0.7 and later).  Since it will be modified, template must not be a string constant, but should be declared as a
       character array.  The file is opened with the O_EXCL flag, guaranteeing that when mkstemp returns successfully we are the only user.

RETURN VALUE
       The mkstemp() function returns the file descriptor fd of the temporary file or -1 on error.

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

       EEXIST Could not create a unique temporary filename.  Now the contents of template are undefined.

NOTES
       The old behaviour (creating a file with mode 0666) may be a security risk, especially since other Unix  flavours  use  0600,  and  somebody
       might overlook this detail when porting programs.

       More generally, the POSIX specification does not say anything about file modes, so the application should make sure its umask is set appro-
       priately before calling mkstemp.

CONFORMING TO
       BSD 4.3, POSIX 1003.1-2001

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

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

GNU
								    2001-12-23								MKSTEMP(3)