MKTEMP(3C)MKTEMP(3C)NAME
mktemp, mkstemp - make a unique file name
SYNOPSIS
#include <stdio.h>
char *mktemp (char *template);
int mkstemp(char *template);
DESCRIPTION
Mktemp replaces the contents of the string pointed to by template by a
unique file name, and returns the address of template. The string in
template should look like a file name with six trailing Xs; mktemp will
replace the Xs with a string that can be used to create a unique file
name.
Mkstemp makes the same replacement to the template but returns a file
descriptor for the template file open for reading and writing. Mkstemp
avoids the race between testing whether the file exists and opening it
for use.
The mkstemp routine is from the 4.3BSD standard C library.
SEE ALSOgetpid(2), tmpfile(3S), tmpnam(3S).
DIAGNOSTICS
Mktemp will assign a zero to the first character of template if it cannot
create a unique name, returning the empty string.
Mkstemp returns an open file descriptor upon success. It returns -1 if
no suitable file could be created.
CAVEAT
Mktemp makes 26 attempts to generate a filename which is not currently in
use from a given template. Since the filename generated uses the process
ID as a base, it is highly unlikely that these names will conflict with
those generated by another process. Variation in the contents of the
actual string given to mktemp, as well as the number of times mktemp is
called, will determine the likelihood of successfully generating a unique
name.
Page 1
