method
Process.poll
Process.poll(handle) -> int
Returns -1 while the child is still running and its exit code once it has ended; it never waits. The code is kept, so asking again gives the same answer until Process.free.
A child ended by a signal (macOS) answers 128 plus the signal number, as a shell reports it — 137 after Process.kill, on both platforms. On Windows the code is the child's DWORD exit code as an int, so a crash such as 0xC0000005 arrives as a negative number (test for != 0, not > 0); a code of 0xFFFFFFFF is reported as 255 so that -1 always means "still running". A handle that is not one answers 255.
Example
program Demo {
var game: int = -1
handler Watch phase Update {
if game >= 0 {
let code = Process.poll(handle: game)
if code >= 0 or code < -1 {
if code != 0 { print("the game crashed") }
Process.free(handle: game)
game = -1
}
}
}
}