npm install getport
Find an open port to listen on.
var getport = require('getport')
getport(function (e, p) {
if (e) throw e
server.listen(p)
})Note: getport uses a TCP client to check the ports and see if anyone has bound to them. If you do not have permission to bind to a port you may still get an error.
getport(5000, function (e, p) {
if (e) throw e
assert.equal(5000, p)
})getport(6000, 5999, function (e, p) {
assert.ok(e)
})