func addHandler(h *pcap.Pcap, dumper *pcap.PcapDumper) {
c := make(chan os.Signal, 1)
signal.Notify(c, os.Interrupt)
go func() {
for sig := range c {
fmt.Fprintln(os.Stderr, "tcpdump: received signal:", sig)
if os.Interrupt == sig {
h.PcapDumpClose(dumper)
h.Close()
os.Exit(1)
}
}
}()
}