use File::Spec::Functions qw( devnull ); use IPC::Open3 qw( open3 ); { my @cmd = ( $tshark_binary => ( -r => $pcap, -e => "frame.number", -e => "frame.time_epoch", -e => "ip.src", -e => "ip.id", -T => "text", -T => "fields", -E => "separator=," ), ); open(local *CHILD_STDIN, '<', devnull) or die $!; open(local *CHILD_STDOUT, '>', $file_temp) or die $!; my $pid = open3('<&CHILD_STDIN', '>&CHILD_STDOUT', '>&STDERR', @cmd); waitpid($pid, 0); }