TMPNAM(3S)                           BSD                            TMPNAM(3S)



NAME
     tmpnam - create a name for a temporary file

SYNOPSIS
     #include <stdio.h>

     char *tmpnam (s)
     char *s;

DESCRIPTION
     tmpnam generates file names that can safely be used for a temporary file.
     It always generates a filename using the path-prefix defined as P_tmpdir
     in the <stdio.h> header file.  If s is NULL, tmpnam leaves its result in
     an internal static area and returns a pointer to that area.  The next
     call to tmpnam will destroy the contents of the area.  If s is not NULL,
     it is assumed to be the address of an array of at least L_tmpnam bytes,
     where L_tmpnam is a constant defined in <stdio.h>; tmpnam places its
     result in that array and returns s.

NOTES
     tmpnam generates a different filename each time it is called.

     Files created using tmpnam and either fopen(3S) or creat(2) are temporary
     only in the sense that they reside in a directory intended for temporary
     use, and their names are unique.  It is the user's responsibility to use
     unlink(2) to remove the file when its use is ended.

SEE ALSO
     creat(2), unlink(2), fopen(3S), mktemp(3), tmpfile(3S).

CAVEATS
     If called more than TMP_MAX times in a single process, tmpnam starts to
     recycle previously used names.

     Between the time a filename is created and the file is opened, it is
     possible for some other process to create a file with the same name.
     This can never happen if that other process is using tmpnam or mktemp,
     and the file names are chosen to render duplication by other means
     unlikely.