use strict; $|++; if( $ARGV[0] eq 'child' ) { sleep 1; print STDOUT "stdout1\n"; sleep 1; print STDERR "stderr1\n"; sleep 1; print STDOUT "stdout2\n"; sleep 1; print STDERR "stderr2\n"; exit; } use Tk; use Tk::ROText; my $mw = MainWindow->new; my $text = $mw->ROText()->pack( -fill => 'both', -expand => 1 ); $text->tagConfigure( 'red', -foreground => 'red' ); use IO::Handle; my $stdin = IO::Handle->new(); my $stdout = IO::Handle->new(); my $stderr = IO::Handle->new(); use IPC::Open3; my $pid = open3( $stdin, $stdout, $stderr, "$0 child" ) || die; $stdin->close; $stdout->autoflush( 1 ); $stderr->autoflush( 1 ); $mw->fileevent( $stdout, readable => \&read_stdout ); $mw->fileevent( $stderr, readable => \&read_stderr ); MainLoop; sub read_stdout { print "read_stdout()\n"; my $num = $stdout->sysread( my $buffer, 1024 ); print "sysread() got $num bytes:\n[$buffer]\n"; $text->insert( 'end', $buffer ); } sub read_stderr { print "read_stderr()\n"; my $num = $stderr->sysread( my $buffer, 1024 ); print "sysread() got $num bytes:\n[$buffer]\n"; $text->insert( 'end', $buffer, 'red' ); }