posix_spawn_file_actions_init.3   [plain text]

.\"
.\" Copyright (c) 2000-2007 Apple Inc. All rights reserved.
.\"
.\" @APPLE_OSREFERENCE_LICENSE_HEADER_START@
.\" 
.\" This file contains Original Code and/or Modifications of Original Code
.\" as defined in and that are subject to the Apple Public Source License
.\" Version 2.0 (the 'License'). You may not use this file except in
.\" compliance with the License. The rights granted to you under the License
.\" may not be used to create, or enable the creation or redistribution of,
.\" unlawful or unlicensed copies of an Apple operating system, or to
.\" circumvent, violate, or enable the circumvention or violation of, any
.\" terms of an Apple operating system software license agreement.
.\" 
.\" Please obtain a copy of the License at
.\" http://www.opensource.apple.com/apsl/ and read it before using this file.
.\" 
.\" The Original Code and all software distributed under the License are
.\" distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
.\" EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
.\" INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
.\" FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
.\" Please see the License for the specific language governing rights and
.\" limitations under the License.
.\" 
.\" @APPLE_OSREFERENCE_LICENSE_HEADER_END@
.\"
.\"     @(#)posix_spawn_file_actions_init.3
.
.Dd August 22, 2007
.Dt POSIX_SPAWN_FILE_ACTIONS_INIT 3
.Os "Mac OS X"
.Sh NAME
.Nm posix_spawn_file_actions_init
.Nm posix_spawn_file_actions_destroy
.Nd initialize or destroy spawn file actions objects
.Sh SYNOPSIS
.Fd #include <spawn.h>
.Ft int
.Fo posix_spawn_file_actions_init
.Fa "posix_spawn_file_actions_t *file_actions"
.Fc
.Ft int
.Fo posix_spawn_file_actions_destroy
.Fa "posix_spawn_file_actions_t *file_actions"
.Fc
.Sh DESCRIPTION
The
.Fn posix_spawn_file_actions_init
function initializes the object referenced by
.Em file_actions ,
to an empty set of file actions for subsequent use in a call to
.Xr posix_spawn 2
or 
.Xr posix_spawnp 2 .
A
.Em posix_spawn_file_actions_t
object is an opaque type that is used to collect set of file actions
specified by calls to
.Xr posix_spawn_file_actions_addclose 3
and
.Xr posix_spawn_file_actions_addopen 3
such that once the spawn operation is complete, the child process will
have a different set of file descriptors than the parent, in the order
that the operations were added to the
.Em posix_spawn_file_actions_t .
.Pp
Additionally, any descriptor in the parent not modified by a file action,
and which has the FD_CLOEXEC flag set, will be closed in the child.
.Pp
The
.Fn posix_spawn_file_actions_destroy
function destroys the object referenced by
.Em file_actions
which was previously intialized by
.Fn posix_spawn_file_actions_init ,
returning any resources obtained at the time of initialization to the
system for subsequent reuse.  A
.Em posix_spawn_file_actions_t
may be reinitialized after having been destroyed, but
.Em must not
be reused after destruction, unless it has been reinitialized.
.Sh RETURN VALUES
On success, these functions return 0; on failure they return an error
number from
.In errno.h .
.Sh ERRORS
These functions will fail and return an error if:
.Bl -tag -width Er
.\" ==========
.It Bq Er ENOMEM
Insufficient resources to initialize the
.Fa posix_spawn_file_actions_t
object.
.\" ==========
.It Bq Er EINVAL
The
.Fa posix_spawn_file_actions_t
being destroyed is invalid.
.El
.Sh SEE ALSO
.Xr posix_spawn 2 ,
.Xr posix_spawnp 2 ,
.Xr posix_spawn_file_actions_addclose 3 ,
.Xr posix_spawn_file_actions_addopen 3 ,
.Xr posix_spawn_file_actions_adddup2 3
.Sh STANDARDS
.St -susv3 [SPN]
.Sh HISTORY
The
.Fn posix_spawn_file_actions_init
and
.Fn posix_spawn_file_actions_destroy
function calls appeared in
.St -susv3 [SPN] .