use signal

Unix signal handling with polling-based API.

Signals are caught and stored as flags. Use pending() to check if a signal was received, and clear() to reset the flag.

Example:

use signal

fn main() {
    signal::SigInt signal::trap
    "Running. Press Ctrl+C to stop." print nl

    loop {
        signal::SigInt signal::pending if {
            "Shutting down" print nl
            signal::SigInt signal::clear
            break
        }
    }
}

Functions

fn clear

Clear the pending flag for a signal.

Signature: (signum:i64 -- )

Example:

signal::SigInt signal::clear

fn ignore

Ignore the specified signal completely.

Signature: (signum:i64 -- )

Example:

signal::SigPipe signal::ignore

fn kill

Send a signal to another process.

Signature: (pid:i64 signum:i64 -- result:i64)

Example:

1234 signal::SigTerm signal::kill drop

fn pending

Check if a signal is pending (received but not cleared). Returns 1 if pending, 0 otherwise. Does not clear the flag.

Signature: (signum:i64 -- flag:i64)

Example:

signal::SigInt signal::pending

fn raise

Send a signal to the current process.

Signature: (signum:i64 -- result:i64)

Example:

signal::SigUsr1 signal::raise drop

fn reset

Reset signal to default behavior.

Signature: (signum:i64 -- )

Example:

signal::SigInt signal::reset

fn SigAbrt

Abort signal.

Signature: ( -- val:i64)

fn SigAlrm

Alarm clock.

Signature: ( -- val:i64)

fn SigChld

Child process stopped or terminated.

Signature: ( -- val:i64)

fn SigCont

Continue if stopped.

Signature: ( -- val:i64)

fn SigFpe

Floating point exception.

Signature: ( -- val:i64)

fn SigHup

Hangup signal (terminal closed).

Signature: ( -- val:i64)

fn SigIll

Illegal instruction.

Signature: ( -- val:i64)

fn SigInt

Interrupt signal (Ctrl+C).

Signature: ( -- val:i64)

fn SigKill

Kill signal (cannot be caught).

Signature: ( -- val:i64)

fn SigPipe

Broken pipe.

Signature: ( -- val:i64)

fn SigQuit

Quit signal (Ctrl+).

Signature: ( -- val:i64)

fn SigSegv

Segmentation fault.

Signature: ( -- val:i64)

fn SigStop

Stop signal (cannot be caught).

Signature: ( -- val:i64)

fn SigTerm

Termination signal.

Signature: ( -- val:i64)

fn SigTstp

Terminal stop (Ctrl+Z).

Signature: ( -- val:i64)

fn SigTtin

Background read from terminal.

Signature: ( -- val:i64)

fn SigTtou

Background write to terminal.

Signature: ( -- val:i64)

fn SigUsr1

User-defined signal 1.

Signature: ( -- val:i64)

fn SigUsr2

User-defined signal 2.

Signature: ( -- val:i64)

fn trap

Install a handler to catch the specified signal. After trapping, the signal sets a pending flag instead of causing the default action (e.g., termination).

Signature: (signum:i64 -- )

Example:

signal::SigInt signal::trap

fn wait

Block until any trapped signal is received. Returns the signal number that was received.

Signature: ( -- signum:i64)

Example:

signal::wait  // sig