POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE(3C) Standard C Library Functions
posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen -
add close or open action to spawn file actions object
Standard C Library (libc, -lc)
#include <spawn.h>
int
posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
int fildes);
int
posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *restrict file_actions,
int fildes, const char *restrict path, int oflag, mode_t mode);
These functions add or delete a close or open action to a spawn file
actions object.
A spawn file actions object is of type posix_spawn_file_actions_t
(defined in <spawn.h>) and is used to specify a series of actions to be
performed by a posix_spawn(3C) or posix_spawnp(3C) operation to arrive
at the set of open file descriptors for the child process given the set
of open file descriptors of the parent.
A spawn file actions object, when passed to posix_spawn() or
posix_spawnp(), specifies how the set of open file descriptors in the
calling process is transformed into a set of potentially open file
descriptors for the spawned process. This transformation occurs as
though the specified sequence of actions was performed exactly once, in
the context of the spawned process (prior to execution of the new
process image), in the order in which the actions were added to the
object. Additionally, when the new process image is executed, any file
descriptor (from this new set) which has its FD_CLOEXEC flag set is
closed (see posix_spawn(3C)).
The posix_spawn_file_actions_addclose() function adds a close action to
the object referenced by file_actions that causes the file descriptor
fildes to be closed (as if close(fildes) had been called) when a new
process is spawned using this file actions object.
The posix_spawn_file_actions_addopen() function adds an open action to
the object referenced by file_actions that causes the file named by
path to be opened (as if open(path, oflag, mode) had been called, and
the returned file descriptor, if not fildes, had been changed to
fildes) when a new process is spawned using this file actions object.
If fildes was already an open file descriptor, it is closed before the
new file is opened.
The string described by path is copied by the
posix_spawn_file_actions_addopen() function.
Upon successful completion, these functions return 0. Otherwise, an
error number is returned to indicate the error.
These functions will fail if:
EBADF The value specified by fildes is negative or greater
than or equal to {OPEN_MAX}.
These functions may fail if:
EINVAL The value specified by file_actions is invalid.
ENOMEM Insufficient memory exists to add to the spawn file
actions object.
It is not considered an error for the fildes argument passed to these
functions to specify a file descriptor for which the specified
operation could not be performed at the time of the call. Any such
error will be detected when the associated file actions object is later
used during a posix_spawn() or posix_spawnp() operation.
If a close(2) operation is specified for a file descriptor that is not
open at the time of the call to posix_spawn() or posix_spawnp(), the
close operation will not cause the posix_spawn() or posix_spawnp()
operation to fail.
Committed
MT-LEVEL
MT-Safe
close(2), dup(2), open(2), posix_spawn(3C),
posix_spawn_file_actions_adddup2(3C),
posix_spawn_file_actions_destroy(3C), attributes(7), standards(7)
The posix_spawn_file_actions_addclose() and
posix_spawn_file_actions_addopen() functions conform to IEEE Std
1003.1-2001 ("POSIX.1").
illumos July 4, 2026 illumos
NAME
posix_spawn_file_actions_addclose, posix_spawn_file_actions_addopen -
add close or open action to spawn file actions object
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <spawn.h>
int
posix_spawn_file_actions_addclose(posix_spawn_file_actions_t *file_actions,
int fildes);
int
posix_spawn_file_actions_addopen(posix_spawn_file_actions_t *restrict file_actions,
int fildes, const char *restrict path, int oflag, mode_t mode);
DESCRIPTION
These functions add or delete a close or open action to a spawn file
actions object.
A spawn file actions object is of type posix_spawn_file_actions_t
(defined in <spawn.h>) and is used to specify a series of actions to be
performed by a posix_spawn(3C) or posix_spawnp(3C) operation to arrive
at the set of open file descriptors for the child process given the set
of open file descriptors of the parent.
A spawn file actions object, when passed to posix_spawn() or
posix_spawnp(), specifies how the set of open file descriptors in the
calling process is transformed into a set of potentially open file
descriptors for the spawned process. This transformation occurs as
though the specified sequence of actions was performed exactly once, in
the context of the spawned process (prior to execution of the new
process image), in the order in which the actions were added to the
object. Additionally, when the new process image is executed, any file
descriptor (from this new set) which has its FD_CLOEXEC flag set is
closed (see posix_spawn(3C)).
The posix_spawn_file_actions_addclose() function adds a close action to
the object referenced by file_actions that causes the file descriptor
fildes to be closed (as if close(fildes) had been called) when a new
process is spawned using this file actions object.
The posix_spawn_file_actions_addopen() function adds an open action to
the object referenced by file_actions that causes the file named by
path to be opened (as if open(path, oflag, mode) had been called, and
the returned file descriptor, if not fildes, had been changed to
fildes) when a new process is spawned using this file actions object.
If fildes was already an open file descriptor, it is closed before the
new file is opened.
The string described by path is copied by the
posix_spawn_file_actions_addopen() function.
RETURN VALUES
Upon successful completion, these functions return 0. Otherwise, an
error number is returned to indicate the error.
ERRORS
These functions will fail if:
EBADF The value specified by fildes is negative or greater
than or equal to {OPEN_MAX}.
These functions may fail if:
EINVAL The value specified by file_actions is invalid.
ENOMEM Insufficient memory exists to add to the spawn file
actions object.
It is not considered an error for the fildes argument passed to these
functions to specify a file descriptor for which the specified
operation could not be performed at the time of the call. Any such
error will be detected when the associated file actions object is later
used during a posix_spawn() or posix_spawnp() operation.
If a close(2) operation is specified for a file descriptor that is not
open at the time of the call to posix_spawn() or posix_spawnp(), the
close operation will not cause the posix_spawn() or posix_spawnp()
operation to fail.
INTERFACE STABILITY
Committed
MT-LEVEL
MT-Safe
SEE ALSO
close(2), dup(2), open(2), posix_spawn(3C),
posix_spawn_file_actions_adddup2(3C),
posix_spawn_file_actions_destroy(3C), attributes(7), standards(7)
STANDARDS
The posix_spawn_file_actions_addclose() and
posix_spawn_file_actions_addopen() functions conform to IEEE Std
1003.1-2001 ("POSIX.1").
illumos July 4, 2026 illumos