mirror of https://github.com/mkerrisk/man-pages
106 lines
3.3 KiB
Groff
106 lines
3.3 KiB
Groff
.\" Copyright (c) 1999 Andries Brouwer (aeb@cwi.nl)
|
|
.\"
|
|
.\" Permission is granted to make and distribute verbatim copies of this
|
|
.\" manual provided the copyright notice and this permission notice are
|
|
.\" preserved on all copies.
|
|
.\"
|
|
.\" Permission is granted to copy and distribute modified versions of this
|
|
.\" manual under the conditions for verbatim copying, provided that the
|
|
.\" entire resulting derived work is distributed under the terms of a
|
|
.\" permission notice identical to this one.
|
|
.\"
|
|
.\" Since the Linux kernel and libraries are constantly changing, this
|
|
.\" manual page may be incorrect or out-of-date. The author(s) assume no
|
|
.\" responsibility for errors or omissions, or for damages resulting from
|
|
.\" the use of the information contained herein. The author(s) may not
|
|
.\" have taken the same level of care in the production of this manual,
|
|
.\" which is licensed free of charge, as they might when working
|
|
.\" professionally.
|
|
.\"
|
|
.\" Formatted or processed versions of this manual, if unaccompanied by
|
|
.\" the source, must acknowledge the copyright and authors of this work.
|
|
.\"
|
|
.TH TEMPNAM 3 1999-06-14 "" "Linux Programmer's Manual"
|
|
.SH NAME
|
|
tempnam \- create a name for a temporary file
|
|
.SH SYNOPSIS
|
|
.nf
|
|
.B #include <stdio.h>
|
|
.sp
|
|
.BI "char *tempnam(const char *" dir ", const char *" pfx );
|
|
.fi
|
|
.SH DESCRIPTION
|
|
The
|
|
.BR tempnam ()
|
|
function returns a pointer to a string that is a valid filename,
|
|
and such that a file with this name did not exist when
|
|
.BR tempnam ()
|
|
checked.
|
|
The filename suffix of the pathname generated will start with
|
|
.I pfx
|
|
in case
|
|
.I pfx
|
|
is a non-NULL string of at most five bytes.
|
|
The directory prefix part of the pathname generated is required to
|
|
be `appropriate' (often that at least implies writable).
|
|
Attempts to find an appropriate directory go through the following
|
|
steps: (i) In case the environment variable TMPDIR exists and
|
|
contains the name of an appropriate directory, that is used.
|
|
(ii) Otherwise, if the
|
|
.I dir
|
|
argument is non-NULL and appropriate, it is used.
|
|
(iii) Otherwise,
|
|
.I P_tmpdir
|
|
(as defined in
|
|
.IR <stdio.h> )
|
|
is used when appropriate.
|
|
(iv) Finally an implementation-defined directory may be used.
|
|
.SH "RETURN VALUE"
|
|
The
|
|
.BR tempnam ()
|
|
function returns a pointer to a unique temporary
|
|
filename, or NULL if a unique name cannot be generated.
|
|
.SH ERRORS
|
|
.TP
|
|
.B ENOMEM
|
|
Allocation of storage failed.
|
|
.LP
|
|
.SH NOTES
|
|
SUSv2 does not mention the use of TMPDIR; glibc will use it only
|
|
when the program is not set-user-ID.
|
|
SVID2 specifies that the directory used under (iv) is
|
|
.IR /tmp .
|
|
SVID2 specifies that the string returned by
|
|
.BR tempnam ()
|
|
was allocated using
|
|
.BR malloc (3)
|
|
and hence can be freed by
|
|
.BR free (3).
|
|
.LP
|
|
The
|
|
.BR tempnam ()
|
|
function generates a different string each time it is called,
|
|
up to TMP_MAX (defined in
|
|
.IR <stdio.h> )
|
|
times. If it is called more than TMP_MAX times,
|
|
the behaviour is implementation defined.
|
|
.LP
|
|
In case the
|
|
.I pfx
|
|
argument has length larger than five, glibc will use the first
|
|
five bytes.
|
|
Upon failure to find a unique name, glibc will return EEXIST.
|
|
.SH BUGS
|
|
The precise meaning of `appropriate' is undefined;
|
|
it is unspecified how accessibility of a directory is determined.
|
|
Never use this function. Use
|
|
.BR mkstemp (3)
|
|
instead.
|
|
.SH "CONFORMING TO"
|
|
SVID 2, 4.3BSD, POSIX 1003.1-2003
|
|
.SH "SEE ALSO"
|
|
.BR mkstemp (3),
|
|
.BR mktemp (3),
|
|
.BR tmpfile (3),
|
|
.BR tmpnam (3)
|