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[apple/xnu.git] / bsd / man / man3 / posix_spawn_file_actions_init.3

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.\"     @(#)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] .