Enum nix::sys::wait::WaitStatus

pub enum WaitStatus {
    Exited(Pid, i32),
    Signaled(Pid, Signal, bool),
    Stopped(Pid, Signal),
    PtraceEvent(Pid, Signal, c_int),
    PtraceSyscall(Pid),
    Continued(Pid),
    StillAlive,
}

Possible return values from wait() or waitpid().

Each status (other than StillAlive) describes a state transition in a child process Pid, such as the process exiting or stopping, plus additional data about the transition if any.

Note that there are two Linux-specific enum variants, PtraceEvent and PtraceSyscall. Portable code should avoid exhaustively matching on WaitStatus.

Variants

Exited(Pid, i32)

Tuple Fields

0: Pid

1: i32

The process exited normally (as with exit() or returning from main) with the given exit code. This case matches the C macro WIFEXITED(status); the second field is WEXITSTATUS(status).

Signaled(Pid, Signal, bool)

Tuple Fields

0: Pid

1: Signal

2: bool

The process was killed by the given signal. The third field indicates whether the signal generated a core dump. This case matches the C macro WIFSIGNALED(status); the last two fields correspond to WTERMSIG(status) and WCOREDUMP(status).

Stopped(Pid, Signal)

Tuple Fields

0: Pid

1: Signal

The process is alive, but was stopped by the given signal. This is only reported if WaitPidFlag::WUNTRACED was passed. This case matches the C macro WIFSTOPPED(status); the second field is WSTOPSIG(status).

PtraceEvent(Pid, Signal, c_int)

Tuple Fields

0: Pid

1: Signal

2: c_int

The traced process was stopped by a PTRACE_EVENT_* event. See nix::sys::ptrace and ptrace(2) for more information. All currently-defined events use SIGTRAP as the signal; the third field is the PTRACE_EVENT_* value of the event.

PtraceSyscall(Pid)

Tuple Fields

0: Pid

The traced process was stopped by execution of a system call, and PTRACE_O_TRACESYSGOOD is in effect. See ptrace(2) for more information.

Continued(Pid)

Tuple Fields

0: Pid

The process was previously stopped but has resumed execution after receiving a SIGCONT signal. This is only reported if WaitPidFlag::WCONTINUED was passed. This case matches the C macro WIFCONTINUED(status).

StillAlive

There are currently no state changes to report in any awaited child process. This is only returned if WaitPidFlag::WNOHANG was used (otherwise wait() or waitpid() would block until there was something to report).

Implementations

impl WaitStatus

pub fn pid(&self) -> Option<Pid>

Extracts the PID from the WaitStatus unless it equals StillAlive.

impl WaitStatus

pub fn from_raw(pid: Pid, status: i32) -> Result<WaitStatus>

Convert a raw wstatus as returned by waitpid/wait into a WaitStatus

Errors

Returns an Error corresponding to EINVAL for invalid status values.

Examples

Convert a wstatus obtained from libc::waitpid into a WaitStatus:

use nix::sys::wait::WaitStatus;
use nix::sys::signal::Signal;
let pid = nix::unistd::Pid::from_raw(1);
let status = WaitStatus::from_raw(pid, 0x0002);
assert_eq!(status, Ok(WaitStatus::Signaled(pid, Signal::SIGINT, false)));

Trait Implementations

impl Clone for WaitStatus

fn clone(&self) -> WaitStatus

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for WaitStatus

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Hash for WaitStatus

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl PartialEq<WaitStatus> for WaitStatus

fn eq(&self, other: &WaitStatus) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &WaitStatus) -> bool

This method tests for !=.

impl Copy for WaitStatus

impl Eq for WaitStatus

impl StructuralEq for WaitStatus

impl StructuralPartialEq for WaitStatus