NAME

mkstemp − make a unique file name

SYNOPSIS

#include <stdlib.h>

int mkstemp(char ∗template);

DESCRIPTION

The mkstemp() function replaces the contents of the string pointed to by template by a unique file name, and returns a file descriptor for the file open for reading and writing.  The function thus prevents any possible race condition between testing whether the file exists and opening it for use.  The string in template should look like a file name with six trailing ’X’s; mkstemp() replaces each ’X’ with a character from the portable file name character set.  The characters are chosen such that the resulting name does not duplicate the name of an existing file. 

RETURN VALUES

Upon successful completion, mkstemp() returns an open file descriptor.  Otherwise −1 is returned if no suitable file could be created. 

ERRORS

No errors are defined. 

USAGE

It is possible to run out of letters. 

The mkstemp() function does not check to determine whether the file name part of template exceeds the maximum allowable file name length. 

For portability with X/Open standards prior to XPG4v2, tmpfile(3S) is preferred over this function. 

The mkstemp() function has an explicit 64-bit equivalent.  See interface64(5). 

SEE ALSO

getpid(2), open(2), tmpfile(3S), tmpnam(3S), interface64(5), standards(5)

SunOS 5.6  —  Last change: 26 Feb 1997