1. module portscanner
   1. function portscanner.checkPortStatus (port)
   2. function portscanner.findAPortInUse ()
   3. function portscanner.findAPortNotInUse ()
   4. object portscanner
2. module portscanner.portscanner
   1. function portscanner.portscanner.checkPortStatus (port)
   2. function portscanner.portscanner.findAPortInUse ()
   3. function portscanner.portscanner.findAPortNotInUse ()

module portscanner

function portscanner.checkPortStatus (port)

• description and source-code

  function checkPortStatus(port) {
    var args, host, opts, callback
  
    args = [].slice.call(arguments, 1)
  
    if (typeof args[0] === 'string') {
      host = args[0]
    } else if (typeof args[0] === 'object') {
      opts = args[0]
    } else if (typeof args[0] === 'function') {
      callback = args[0]
    }
  
    if (typeof args[1] === 'object') {
      opts = args[1]
    } else if (typeof args[1] === 'function') {
      callback = args[1]
    }
  
    if (typeof args[2] === 'function') {
      callback = args[2]
    }
  
    if (!callback) return promisify(checkPortStatus, arguments)
  
    opts = opts || {}
  
    host = host || opts.host || '127.0.0.1'
  
    var timeout = opts.timeout || 400
    var connectionRefused = false
  
    var socket = new Socket()
    var status = null
    var error = null
  
    // Socket connection established, port is open
    socket.on('connect', function () {
      status = 'open'
      socket.destroy()
    })
  
    // If no response, assume port is not listening
    socket.setTimeout(timeout)
    socket.on('timeout', function () {
      status = 'closed'
      error = new Error('Timeout (' + timeout + 'ms) occurred waiting for ' + host + ':' + port + ' to be available')
      socket.destroy()
    })
  
    // Assuming the port is not open if an error. May need to refine based on
    // exception
    socket.on('error', function (exception) {
      if (exception.code !== 'ECONNREFUSED') {
        error = exception
      } else {
        connectionRefused = true
      }
      status = 'closed'
    })
  
    // Return after the socket has closed
    socket.on('close', function (exception) {
      if (exception && !connectionRefused) { error = error || exception } else { error = null }
      callback(error, status)
    })
  
    socket.connect(port, host)
  }

• example usage

  ...
  
  A brief example:
  
  ```javascript
  var portscanner = require('portscanner')
  
  // Checks the status of a single port
  portscanner.checkPortStatus(3000, '127.0.0.1', function(error, status) {
    // Status is 'open' if currently in use or 'closed' if available
    console.log(status)
  })
  
  // Find the first available port. Asynchronously checks, so first port
  // determined as available is returned.
  portscanner.findAPortNotInUse(3000, 3010, '127.0.0.1', function(error, port) {
  ...

function portscanner.findAPortInUse ()

• description and source-code

  function findAPortInUse() {
    var params = [].slice.call(arguments)
    params.unshift('open')
    return findAPortWithStatus.apply(null, params)
  }

• example usage

  ...
  // determined as available is returned.
  portscanner.findAPortNotInUse(3000, 3010, '127.0.0.1', function(error, port) {
    console.log('AVAILABLE PORT AT: ' + port)
  })
  
  // Find the first port in use or blocked. Asynchronously checks, so first port
  // to respond is returned.
  portscanner.findAPortInUse(3000, 3010, '127.0.0.1', function(error, port) {
    console.log('PORT IN USE AT: ' + port)
  })
  
  // You can also pass array of ports to check
  portscanner.findAPortInUse([3000, 3005, 3006], '127.0.0.1', function(error, port) {
    console.log('PORT IN USE AT: ' + port)
  })
  ...

function portscanner.findAPortNotInUse ()

• description and source-code

  function findAPortNotInUse() {
    var params = [].slice.call(arguments)
    params.unshift('closed')
    return findAPortWithStatus.apply(null, params)
  }

• example usage

  ...
  portscanner.checkPortStatus(3000, '127.0.0.1', function(error, status) {
  // Status is 'open' if currently in use or 'closed' if available
  console.log(status)
  })
  
  // Find the first available port. Asynchronously checks, so first port
  // determined as available is returned.
  portscanner.findAPortNotInUse(3000, 3010, '127.0.0.1', function(error, port
  ) {
  console.log('AVAILABLE PORT AT: ' + port)
  })
  
  // Find the first port in use or blocked. Asynchronously checks, so first port
  // to respond is returned.
  portscanner.findAPortInUse(3000, 3010, '127.0.0.1', function(error, port) {
  console.log('PORT IN USE AT: ' + port)
  ...

module portscanner.portscanner

function portscanner.portscanner.checkPortStatus (port)

• description and source-code

  function checkPortStatus(port) {
    var args, host, opts, callback
  
    args = [].slice.call(arguments, 1)
  
    if (typeof args[0] === 'string') {
      host = args[0]
    } else if (typeof args[0] === 'object') {
      opts = args[0]
    } else if (typeof args[0] === 'function') {
      callback = args[0]
    }
  
    if (typeof args[1] === 'object') {
      opts = args[1]
    } else if (typeof args[1] === 'function') {
      callback = args[1]
    }
  
    if (typeof args[2] === 'function') {
      callback = args[2]
    }
  
    if (!callback) return promisify(checkPortStatus, arguments)
  
    opts = opts || {}
  
    host = host || opts.host || '127.0.0.1'
  
    var timeout = opts.timeout || 400
    var connectionRefused = false
  
    var socket = new Socket()
    var status = null
    var error = null
  
    // Socket connection established, port is open
    socket.on('connect', function () {
      status = 'open'
      socket.destroy()
    })
  
    // If no response, assume port is not listening
    socket.setTimeout(timeout)
    socket.on('timeout', function () {
      status = 'closed'
      error = new Error('Timeout (' + timeout + 'ms) occurred waiting for ' + host + ':' + port + ' to be available')
      socket.destroy()
    })
  
    // Assuming the port is not open if an error. May need to refine based on
    // exception
    socket.on('error', function (exception) {
      if (exception.code !== 'ECONNREFUSED') {
        error = exception
      } else {
        connectionRefused = true
      }
      status = 'closed'
    })
  
    // Return after the socket has closed
    socket.on('close', function (exception) {
      if (exception && !connectionRefused) { error = error || exception } else { error = null }
      callback(error, status)
    })
  
    socket.connect(port, host)
  }

• example usage

  ...
  
  A brief example:
  
  ```javascript
  var portscanner = require('portscanner')
  
  // Checks the status of a single port
  portscanner.checkPortStatus(3000, '127.0.0.1', function(error, status) {
    // Status is 'open' if currently in use or 'closed' if available
    console.log(status)
  })
  
  // Find the first available port. Asynchronously checks, so first port
  // determined as available is returned.
  portscanner.findAPortNotInUse(3000, 3010, '127.0.0.1', function(error, port) {
  ...

function portscanner.portscanner.findAPortInUse ()

• description and source-code

  function findAPortInUse() {
    var params = [].slice.call(arguments)
    params.unshift('open')
    return findAPortWithStatus.apply(null, params)
  }

• example usage

  ...
  // determined as available is returned.
  portscanner.findAPortNotInUse(3000, 3010, '127.0.0.1', function(error, port) {
    console.log('AVAILABLE PORT AT: ' + port)
  })
  
  // Find the first port in use or blocked. Asynchronously checks, so first port
  // to respond is returned.
  portscanner.findAPortInUse(3000, 3010, '127.0.0.1', function(error, port) {
    console.log('PORT IN USE AT: ' + port)
  })
  
  // You can also pass array of ports to check
  portscanner.findAPortInUse([3000, 3005, 3006], '127.0.0.1', function(error, port) {
    console.log('PORT IN USE AT: ' + port)
  })
  ...

function portscanner.portscanner.findAPortNotInUse ()

• description and source-code

  function findAPortNotInUse() {
    var params = [].slice.call(arguments)
    params.unshift('closed')
    return findAPortWithStatus.apply(null, params)
  }

• example usage

  ...
  portscanner.checkPortStatus(3000, '127.0.0.1', function(error, status) {
  // Status is 'open' if currently in use or 'closed' if available
  console.log(status)
  })
  
  // Find the first available port. Asynchronously checks, so first port
  // determined as available is returned.
  portscanner.findAPortNotInUse(3000, 3010, '127.0.0.1', function(error, port
  ) {
  console.log('AVAILABLE PORT AT: ' + port)
  })
  
  // Find the first port in use or blocked. Asynchronously checks, so first port
  // to respond is returned.
  portscanner.findAPortInUse(3000, 3010, '127.0.0.1', function(error, port) {
  console.log('PORT IN USE AT: ' + port)
  ...