posix_spawnattr - configure attributes for posix_spawn
#include <spawn.h>
POSIX_SPAWN_RESETIDS
POSIX_SPAWN_SETPGROUP
POSIX_SPAWN_SETSCHEDPARAM
POSIX_SPAWN_SETSCHEDULER
POSIX_SPAWN_SETSIGDEF
POSIX_SPAWN_SETSIGMASK
POSIX_SPAWN_SETSID
struct posix_spawnattr_t;
int posix_spawnattr_init(posix_spawnattr_t*);
int posix_spawnattr_destroy(posix_spawnattr_t*);
int posix_spawnattr_getflags(const posix_spawnattr_t*, short*);
int posix_spawnattr_getpgroup(const posix_spawnattr_t*, pid_t*);
int posix_spawnattr_getschedparam(const posix_spawnattr_t*, struct sched_param*);
int posix_spawnattr_getschedpolicy(const posix_spawnattr_t*, int*);
int posix_spawnattr_getsigdefault(const posix_spawnattr_t*, sigset_t*);
int posix_spawnattr_getsigmask(const posix_spawnattr_t*, sigset_t*);
int posix_spawnattr_setflags(posix_spawnattr_t*, short);
int posix_spawnattr_setpgroup(posix_spawnattr_t*, pid_t);
int posix_spawnattr_setschedparam(posix_spawnattr_t*, const struct sched_param*);
int posix_spawnattr_setschedpolicy(posix_spawnattr_t*, int);
int posix_spawnattr_setsigdefault(posix_spawnattr_t*, const sigset_t*);
int posix_spawnattr_setsigmask(posix_spawnattr_t*, const sigset_t*);Configures a posix_spawnattr_t object for use with posix_spawn(2). This object can be used to let posix_spawn() set up process attributes for the spawned child process. The file actions are executed after creating the new process but before loading its binary.
A posix_spawnattr_t object is allocated on the stack but starts in an undefined state.
posix_spawnattr_init() initializes a posix_spawnattr_t object that is in an undefined state and puts it in a valid state. It has to be called before the object can be passed to any other function.
posix_spawnattr_destroy() frees up resources used by a valid posix_spawn_file_actions_t object and puts it into an undefined state. It has to be called after a posix_spawnattr_t object is no longer needed.
It is valid to alternatingly call posix_spawnattr_init() and posix_spawnattr_destroy() on the same object,
posix_spawnattr_setflags() configures which attributes of the new child process posix_spawn() will set. It receives a bitmask that can contain:
POSIX_SPAWN_RESETIDS: If set, posix_spawn() will reset the effective uid and gid of the child process to the real uid and gid of the parent process. See also setuid_overview(7).
POSIX_SPAWN_SETPGROUP: If set, posix_spawn() will set the process group ID of the child process to the process group ID configured with posix_spawnattr_setpgroup(), as if setpgid(0, pgroup) was called in the child process. The behavior if both this and POSIX_SPAWN_SETSID is set is undefined.
POSIX_SPAWN_SETSCHEDPARAM: If set, posix_spawn() will set the scheduler parameter of the child process to the process group ID configured with posix_spawnattr_setschedparam(), as if sched_setparam(0, schedparam) was called in the child process.
POSIX_SPAWN_SETSCHEDULER: This is not yet implemented in SerenityOS.
POSIX_SPAWN_SETSIGDEF: If set, posix_spawn() will reset the signal handlers of the child process configured with posix_spawnattr_setsigdefault() to each signal's default handler.
POSIX_SPAWN_SETSIGMASK: If set, posix_spawn() will set the signal mask of the child process to the signal mask configured with posix_spawnattr_setsigmask(), as if sigprocmask() was called in the child process.
POSIX_SPAWN_SETSID: If set, posix_spawn() will run the child process in a new session, as if setsid() was called in the child process. The behavior if both this and POSIX_SPAWN_SETPGROUP is set is undefined.
The posix_spawnattr_get* functions return what's been set with the corresponding setters. The default flags and pgroup are 0, the default sigdefault set is sigemptyset(), all other fields have an unspecified default value.
In SerenityOS, these functions always succeed and return 0.
The one exception is posix_spawnattr_setflags(), which can return -1 and set errno to EINVAL if an unknown bit is set in the passed bitmask.
If the effect of an attr fails, the child will exit with exit code 127 before even executing the child binary.