IO::Lambda::Signal - wait for pids and signals
The module provides access to the signal-based callbacks: generic signal listener signal,
process ID listener pid,
and the asynchronous version of system call,
spawn.
use strict;
use IO::Lambda qw(:all);
use IO::Lambda::Signal qw(pid spawn);
# pid
my $pid = fork;
exec "/bin/ls" unless $pid;
lambda {
context $pid, 5;
pid {
my $ret = shift;
print defined($ret) ? ("exitcode(", $ret>>8, ")\n") : "timeout\n";
}
}-> wait;
# spawn
this lambda {
context "perl -v";
spawn {
my ( $buf, $exitcode, $error) = @_;
print "buf=[$buf], exitcode=$exitcode, error=$error\n";
}
}-> wait;
Accepts PID and an optional deadline/timeout, returns either the process' exit status, or undef on timeout. The corresponding lambda is new_pid :
new_pid ($PID, $TIMEOUT) :: () -> $?|undef
Accepts signal name and optional deadline/timeout, returns 1 if the signal was caught, or undef on timeout. The corresponding lambda is new_signal :
new_signal ($SIG, $TIMEOUT) :: () -> boolean
Calls pipe open on @LIST, reads all data printed by the child process, and awaits for the process to finish. Returns three scalars - collected output, process exitcode $?, and an error string (usually $!). The corresponding lambda is new_process :
new_process (@LIST) :: () -> ( output, $?, $!)
Lambda objects created by new_process have an additional field 'pid' initialized with the process pid value.
pid and new_pid don't work on win32 because win32 doesn't use SIGCHLD/waitpid. Native implementation of spawn and new_process doesn't work for the same reason on win32 as well, therefore those were reimplemented using threads, and require a threaded perl.
IO::Lambda, perlipc, IPC::Open2, IPC::Run
Dmitry Karasik, <dmitry@karasik.eu.org>.
