POSIX_SPAWNATTR_SETFL... BSD Library Functions Manual POSIX_SPAWNATTR_SETFL...NAMEposix_spawnattr_setflags posix_spawnattr_getflags — get or set flags on a
posix_spawnattr_t
SYNOPSIS
#include <spawn.h>
int
posix_spawnattr_setflags(posix_spawnattr_t *attr, short flags);
int
posix_spawnattr_getflags(const posix_spawnattr_t *restrict attr,
short *restrict flags);
DESCRIPTION
The posix_spawnattr_setflags() function sets the flags on the attributes
object referenced by attr.
The posix_spawnattr_getflags() function retrieves the flags on the
attributes object referenced by attr.
The argument flags is either 0 or a logical OR of one or more of the fol‐
lowing flags:
POSIX_SPAWN_RESETIDS If this bit is set, the child process will
inherit the real (rather than the effective)
user and group ID of the parent process.
NOTE: This flag has no effect when the set-
group bit is set on the process image being
spawned.
POSIX_SPAWN_SETPGROUP If this bit is not set, then the child
process inherits the parent process group;
if it is set, then the child process will
behave as if the setpgid(2) function had
been called with a pid parameter of 0 and a
pgid parameter equal to the value of the
spawn-pgroup value of the posix_spawnattr_t,
as set by posix_spawnattr_setpgroup(3)
POSIX_SPAWN_SETSIGDEF Signals set to to either be caught or to the
default action in the parent process will
also be set to the default action in the
child process. Signals set to be ignored in
the parent process will be ignored in the
child. However, if this bit is set, then
signals in the spawn-sigdefault value of the
posix_spawnattr_t, as set by
posix_spawnattr_setsigdefault(3) which are
caught or ignored in the parent will instead
be reset to their default actions in the
child.
POSIX_SPAWN_SETSIGMASK If this bit is set, then the initial signal
mask of the child process will be set to the
spawn-sigmask value of the
posix_spawnattr_t, as set by
posix_spawnattr_setsigmask(3).
POSIX_SPAWN_SETEXEC Apple Extension: If this bit is set, rather
than returning to the caller, posix_spawn(2)
and posix_spawnp(2) will behave as a more
featureful execve(2).
POSIX_SPAWN_START_SUSPENDED Apple Extension: If this bit is set, then
the child process will be created with its
task suspended, permitting debuggers, pro‐
filers, and other programs to manipulate the
process before it begins execution in user
space. This permits, for example, obtaining
exact instruction counts, or debugging very
early in dyld(1).
POSIX_SPAWN_CLOEXEC_DEFAULT Apple Extension: If this bit is set, then
only file descriptors explicitly described
by the file_actions argument are available
in the spawned process; all of the other
file descriptors are automatically closed in
the spawned process.
RETURN VALUES
On success, these functions return 0; on failure they return an error
number from <errno.h>. The posix_spawnattr_getflags() additionally, upon
successful completion, modifies the value pointed to be the attr argument
by making it equal to the spawn-flags attribute of the posix_spawnattr_t.
ERRORS
These functions may fail if:
[EINVAL] The value specified by attr is invalid.
[EINVAL] The value of attr is invalid.
SEE ALSOposix_spawn(2), posix_spawnp(2), posix_spawnattr_init(3),
posix_spawnattr_destroy(3), posix_spawnattr_setpgroup(3),
posix_spawnattr_setsigdefault(3), posix_spawnattr_setsigmask(3),
posix_spawn_file_actions_init(3), setpgid(2), execve(2), dyld(1)STANDARDS
Version 3 of the Single UNIX Specification (“SUSv3”) [SPN]
HISTORY
The posix_spawnattr_setflags() and posix_spawnattr_getflags() function
calls appeared in Version 3 of the Single UNIX Specification (“SUSv3”)
[SPN].
Mac OS X October 28, 2010 Mac OS X
