Initial commit checks status of a specified port.

Author: baalexander

example/portscan.js

@@ -0,0 +1,12 @@
+var portscanner = require('../lib/portscanner.js')
+
+portscanner.checkPortStatus('3000', 'localhost', function(error, status) {
+  console.log(status)
+})
+
+portscanner.findAnAvailablePort(3000, 3010, 'localhost', function(error, port) {
+  console.log('AVAILABLE PORT AT ' + port)
+})
+
+setTimeout(function() { }, 10000)
+

lib/portscanner.js

@@ -0,0 +1,69 @@
+var net    = require('net')
+  , Socket = net.Socket
+
+var portscanner = exports
+
+portscanner.findAnAvailablePort = function(startPort, endPort, host, callback) {
+  var that = this
+  var foundAvailablePort = false
+  var numberOfPortsChecked = 0
+
+  var check = function(port) {
+    that.checkPortStatus(port, host, function(error, status) {
+      numberOfPortsChecked++
+      // Only callback once
+      if (foundAvailablePort === false) {
+        if (error) {
+          foundAvailablePort = true
+          callback(error)
+        }
+        else {
+          if (status === 'open') {
+            foundAvailablePort = true
+            callback(null, port)
+          }
+          // All port checks have returned unavailable
+          else if (numberOfPortsChecked === (endPort - startPort + 1)) {
+            callback(null, false)
+          }
+        }
+      }
+    })
+  }
+
+  for (var port = startPort; port <= endPort; port++) {
+    check(port)
+  }
+}
+
+portscanner.checkPortStatus = function(port, host, callback) {
+  var socket = new Socket()
+
+  // Socket connection established, port is open
+  socket.on('connect', function() {
+    console.log('ON CONNECT')
+    socket.end()
+    callback(null, 'open')
+  })
+
+  // If no response, assume port is not listening
+  socket.setTimeout(400)
+  socket.on('timeout', function() {
+    console.log('ON TIMEOUT')
+    socket.end()
+    callback(null, 'closed')
+  })
+
+  // Assuming the port is not open if an error. May need to refine based on
+  // exception
+  socket.on('error', function(exception) {
+    console.log('ON ERROR')
+    //console.log(exception)
+    socket.end()
+    callback(null, 'closed')
+  })
+
+  host = host || 'localhost'
+  socket.connect(port, host)
+}
+