187 lines
4.6 KiB
Groff
187 lines
4.6 KiB
Groff
.\" $NetBSD: mktemp.3,v 1.13 1998/07/28 17:11:12 mycroft Exp $
|
|
.\"
|
|
.\" Copyright (c) 1989, 1991, 1993
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
.\"
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
.\" modification, are permitted provided that the following conditions
|
|
.\" are met:
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
.\" documentation and/or other materials provided with the distribution.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" may be used to endorse or promote products derived from this software
|
|
.\" without specific prior written permission.
|
|
.\"
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
.\" SUCH DAMAGE.
|
|
.\"
|
|
.\" @(#)mktemp.3 8.1 (Berkeley) 6/4/93
|
|
.\"
|
|
.Dd July 28, 1998
|
|
.Dt MKTEMP 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm mktemp ,
|
|
.Nm mkstemp ,
|
|
.Nm mkdtemp
|
|
.Nd make unique temporary file or directory name
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.Fd #include <stdlib.h>
|
|
.Ft char *
|
|
.Fn mktemp "char *template"
|
|
.Ft int
|
|
.Fn mkstemp "char *template"
|
|
.Ft char *
|
|
.Fn mkdtemp "char *template"
|
|
.Sh DESCRIPTION
|
|
The
|
|
.Fn mktemp
|
|
function
|
|
takes the given file name template and overwrites a portion of it
|
|
to create a file name.
|
|
This file name is unique and suitable for use
|
|
by the application.
|
|
The template may be any file name with some number of
|
|
.Ql X Ns s
|
|
appended
|
|
to it, for example
|
|
.Pa /tmp/temp.XXXX .
|
|
The trailing
|
|
.Ql X Ns s
|
|
are replaced with the current process number and/or a
|
|
unique letter combination.
|
|
The number of unique file names
|
|
.Fn mktemp
|
|
can return depends on the number of
|
|
.Ql X Ns s
|
|
provided; six
|
|
.Ql X Ns s
|
|
will
|
|
result in
|
|
.Fn mktemp
|
|
testing roughly 26 ** 6 combinations.
|
|
.Pp
|
|
The
|
|
.Fn mkstemp
|
|
function
|
|
makes the same replacement to the template and creates the template file,
|
|
mode 0600, returning a file descriptor opened for reading and writing.
|
|
This avoids the race between testing for a file's existence and opening it
|
|
for use.
|
|
.Pp
|
|
The
|
|
.Fn mkdtemp
|
|
function
|
|
is similar to
|
|
.Fn mkstemp ,
|
|
but it creates a mode 0700 directory instead and returns the path.
|
|
.Sh RETURN VALUES
|
|
The
|
|
.Fn mktemp
|
|
and
|
|
.Fn mkdtemp
|
|
functions
|
|
return a pointer to the template on success and
|
|
.Dv NULL
|
|
on failure.
|
|
The
|
|
.Fn mkstemp
|
|
function
|
|
returns \-1 if no suitable file could be created.
|
|
If either call fails an error code is placed in the global variable
|
|
.Va errno .
|
|
.Sh ERRORS
|
|
The
|
|
.Fn mktemp ,
|
|
.Fn mkstemp
|
|
and
|
|
.Fn mkdtemp
|
|
functions
|
|
may set
|
|
.Va errno
|
|
to one of the following values:
|
|
.Bl -tag -width Er
|
|
.It Bq Er ENOTDIR
|
|
The pathname portion of the template is not an existing directory.
|
|
.El
|
|
.Pp
|
|
The
|
|
.Fn mktemp ,
|
|
.Fn mkstemp
|
|
and
|
|
.Fn mkdtemp
|
|
functions
|
|
may also set
|
|
.Va errno
|
|
to any value specified by the
|
|
.Xr stat 2
|
|
function.
|
|
.Pp
|
|
The
|
|
.Fn mkstemp
|
|
function
|
|
may also set
|
|
.Va errno
|
|
to any value specified by the
|
|
.Xr open 2
|
|
function.
|
|
.Pp
|
|
The
|
|
.Fn mkdtemp
|
|
function
|
|
may also set
|
|
.Va errno
|
|
to any value specified by the
|
|
.Xr mkdir 2
|
|
function.
|
|
.Sh SEE ALSO
|
|
.Xr chmod 2 ,
|
|
.Xr getpid 2 ,
|
|
.Xr open 2 ,
|
|
.Xr stat 2
|
|
.Sh HISTORY
|
|
A
|
|
.Fn mktemp
|
|
function appeared in
|
|
.At v7 .
|
|
.Pp
|
|
The
|
|
.Fn mkstemp
|
|
function appeared in
|
|
.Bx 4.4 .
|
|
.Pp
|
|
The
|
|
.Fn mkdtemp
|
|
function appeared in
|
|
.Nx 1.4 .
|
|
.Sh SECURITY CONSIDERATIONS
|
|
The use of
|
|
.Fn mktemp
|
|
should generally be avoided, as a hostile process can exploit a race
|
|
condition in the time between the generation of a temporary filename by
|
|
.Fn mktemp
|
|
and the invoker's use of the temporary name.
|
|
A link-time warning will be issued advising the use of
|
|
.Fn mkstemp
|
|
or
|
|
.Fn mkdtemp
|
|
instead.
|