HP-UX Reference (11i v2 04/09) - 3 Library Functions A-M (vol 6)

mktemp(3C) mktemp(3C)

NAME

mktemp( ), mkstemp( ) - make a unique ﬁle name

SYNOPSIS

#include <stdlib.h>

char *mktemp(char *template);

int mkstemp(char *template);

Remarks:

These functions are provided solely for backward compatibility and importability of applications,

and are not recommended for new applications where portability is important. For portable appli-

cations, use tmpfile() instead (see tmpﬁle(3S)).

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() replaces the Xs with a letter and the current process

ID. The letter is chosen such that the

resulting name does not duplicate the name of an existing ﬁle. If there are fewer than six

Xs, the letter is

dropped ﬁrst, followed by dropping the high-order digits of the process

ID.

mkstemp() makes the same replacement to the template, but also returns a ﬁle descriptor for the tem-

plate ﬁle after opening the ﬁle for reading and writing. mkstemp() thus prevents any possible race

condition between testing whether the ﬁle exists and opening it for use.

RETURN VALUE

mktemp() returns its argument except when it runs out of letters, in which case the result is a pointer to

the empty string "".

mkstemp() returns an open ﬁle descriptor upon successful completion, or -1 if no suitable ﬁle could be

created.

WARNINGS

It is possible to run out of letters.

mktemp() and mkstemp() do not check to determine whether the ﬁle name part of template exceeds

the maximum allowable ﬁle name length.