freeport-async
Finds an available port for your application to use. You can specify a range where to look for an available port. And can also find a range of available ports for you to use. You can also be used to test to see if a given port is available.
All functions are async and return Promises.
Usage
Basic
let freeportAsync = ; let portICanUse = await ;
Advanced
let freeportAsync = ; let portIn9000Range = await ; let portAvailableForAnyOrLocalhost = await ; let isPort5000Available = await freeportAsync; let listOf5ConsecutiveAvailablePorts = await freeportAsync; let freeRangeIn12000Range = await freeportAsync;
Important Note
Note that this code just finds available ports, but doesn't reserve them in any way. This means that if you have other code that might be looking for a port in the same range at the same time, you could run into issues.
Also, if you call freeportAsync
twice in a row, it will often return the same port number twice. If you want to find two (or more) ports you can use, you need to call freeportAsync.rangeAsync(<number-of-ports>, [startSearchFrom])
.