code: function listen(file, perm) {
    var args = [file]
      , perm = perm || 0700
      , server = this;
  
    this.file = file;
    this.name = path.basename(file);
  
    if(this.name === file) {
      file = path.join(process.cwd(), file);
    }
  
    function onListen() {
      try {
        fs.chmodSync(file, perm);
      }catch(e){}
      log.notice('accepting connections at %s', file);
    }
    args.push(onListen);
  
    // jump through some hoops for stale sockets
    server.on('error', function (e) {
      if(e.code == 'EADDRINUSE') {
        var client = new net.Socket();
        // handle error trying to talk to server
        client.on('error', function(e) {
          // no other server listening
          if(e.code == 'ECONNREFUSED') {
            fs.unlinkSync(file);
            TcpServer.prototype.listen.apply(server, args);
          }
        });
        client.connect({path: file}, function() {
          // exit with original EADDRINUSE
          throw e;
        });
      }
    });
    Server.prototype.listen.apply(server, args);
  }
docs: Listen on a UNIX domain socket.