fd.4 revision c10c16dec587a0662068f6e2991c29ed3a9db943
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Copyright (c) 1993, Sun Microsystems, Inc. All Rights Reserved.
Copyright 1989 AT&T
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
Copyright (c) 1993, Sun Microsystems, Inc. All Rights Reserved.
Copyright 1989 AT&T
The contents of this file are subject to the terms of the Common Development and Distribution License (the "License"). You may not use this file except in compliance with the License.
You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE or http://www.opensolaris.org/os/licensing. See the License for the specific language governing permissions and limitations under the License.
When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
fd 4 "3 Jul 1990" "SunOS 5.11" "File Formats"
NAME
fd - file descriptor files
DESCRIPTION
These files, conventionally called /dev/fd/0, /dev/fd/1, /dev/fd/2, and so on, refer to files accessible through file descriptors. If file descriptor n is open, these two system calls have the same effect:
fd = open("/dev/fd/n",mode); fd = dup(n);
On these files creat(2) is equivalent to open, and mode is ignored. As with dup, subsequent reads or writes on fd fail unless the original file descriptor allows the operations.
For convenience in referring to standard input, standard output, and standard error, an additional set of names is provided: /dev/stdin is a synonym for /dev/fd/0, /dev/stdout for /dev/fd/1, and /dev/stderr for /dev/fd/2.
SEE ALSO
creat(2), dup(2), open(2)
DIAGNOSTICS
open(2) returns -1 and EBADF if the associated file descriptor is not open.