Works either way, but it's more correct to send SIGTERM

This signal terminates tshark or dumpcap. SIGINT will do the job too,
and tshark will catch both signals, but SIGTERM is intended for
programmatic signalling.

pcap/cmds_unix.go

@@ -25,5 +25,5 @@ func (c *Command) Kill() error {
 	if c.Cmd.Process == nil {
 		return errors.WithStack(ProcessNotStarted{Command: c.Cmd})
 	}
-	return syscall.Kill(-c.Cmd.Process.Pid, syscall.SIGINT)
+	return syscall.Kill(-c.Cmd.Process.Pid, syscall.SIGTERM)
 }