bsd man page for mkstemp

MKTEMP(3)						     Library Functions Manual							 MKTEMP(3)

NAME
       mktemp - make a unique file name

SYNOPSIS
       char *mktemp(template)
       char *template;

       mkstemp(template)
       char *template;

DESCRIPTION
       Mktemp creates a unique file name and returns the address of the template.  The template should contain a file name with trailing X's, nor-
       mally something like /tmp/tempXXXXXX.  The X's are replaced by the current process number and/or  a  unique  letter  combination.   Mkstemp
       makes the same replacement to the template but opens the template file and returns a file descriptor open for reading and writing.  Mkstemp
       avoids the race between testing whether the file exists and opening it for use.	The number of file name combinations  mktemp  and  mkstemp
       will try depends on the number of X's placed on the end of the template; six X's will result in them trying roughly 26 ** 6 combinations.

SEE ALSO
       access(2), getpid(2), open(2)

DIAGNOSTICS
       Mktemp returns NULL on failure, mkstemp returns -1 if no suitable file could be created.

7th Edition							  April 10, 1987							 MKTEMP(3)