1 files changed, 39 insertions, 5 deletions

diff --git a/lib/App/Beam/Command.pm b/lib/App/Beam/Command.pm
index 79b8b06..4f92cdf 100644
--- a/lib/App/Beam/Command.pm
+++ b/lib/App/Beam/Command.pm
@@ -12,6 +12,7 @@ our %EXPORT_TAGS = (
 
 use IPC::Open3;
 use Symbol 'gensym';
+use POSIX qw(:sys_wait_h);
 
 sub new {
     my $class = shift;
@@ -28,6 +29,24 @@ use constant {
     CHAN_STDERR => 1
 };
 
+sub start_log {
+    my ($self, $chan, $rfd) = @_;
+
+    if (exists($self->{log}) && defined($self->{log}[$chan])) {
+	local $^F = fileno($rfd);
+	my $pid = fork();
+	if ($pid == 0) {
+	    local $_ = $rfd;
+	    &{$self->{log}[CHAN_STDERR]};
+	    exit(0);
+	} else {
+	    push @{$self->{pids}}, $pid;
+	    return undef;
+	}
+    }
+    return $rfd;
+}
+
 sub run {
     my $self = shift;
     my $out = gensym;
@@ -36,25 +55,39 @@ sub run {
     return $self->{status} if exists($self->{status});
 
     eval {
-	my $pid = open3(\*STDIN, $out, $err, @{$self->{argv}});
-	waitpid($pid, 0);
+	push @{$self->{pids}},
+	     open3(\*STDIN, $out, $err, @{$self->{argv}});
+	$out = $self->start_log(CHAN_STDOUT, $out);
+	$err = $self->start_log(CHAN_STDERR, $err);
+	do {
+	    my $pid = waitpid(-1, 0);
+	    if ($pid > 0) {
+		@{$self->{pids}} = grep { $pid != $_ } @{$self->{pids}};
+	    }
+	} while ($#{$self->{pids}} >= 0);
     };
     if ($@) {
 	$self->{status} = $@;
     } else {
 	$self->{status} = $?;
 	local $/ = undef;
-	$self->{channel}[CHAN_STDOUT] = <$out>;
-	$self->{channel}[CHAN_STDERR] = <$err>;
+	$self->{channel}[CHAN_STDOUT] = defined($out) ? <$out> : undef;
+	$self->{channel}[CHAN_STDERR] = defined($err) ? <$err> : undef;
     }
     return $self->{status};
 }
 
+sub set_logger {
+    my ($self, $chan, $fun) = @_;
+    $self->{log}[$chan] = $fun;
+}
+
 sub restart {
     my $self = shift;
 
     delete $self->{status};
     delete $self->{channel};
+    delete $self->{pids};
     return $self->run;
 }
 
@@ -66,7 +99,8 @@ sub status {
 
 sub channel {
     my ($self, $chan) = @_;
-    return undef if !exists($self->{channel}) || $chan > $#{$self->{channel}};
+    return undef
+	unless (exists($self->{channel}) && defined($self->{channel}[$chan]));
     open(my $fd, '<', \$self->{channel}[$chan]) or croak "can't dup: $!"; 
     return $fd;
 }