Mac users may occasionally come across a situation where a process is locking a port, preventing another app or process from using that port. If you come across such a situation, for example maybe you’re trying to use React.js and find out that something is already running on port 3000, you can easily track down … Read More
Occasionally you may find yourself in a situation where you are seeking to find what open TCP connections are in a listening state on a Mac. This can be useful whether you’re troubleshooting particular network issues, or simply looking to identify which processes are listening on specific ports on a Mac. We’ll be using the … Read More
If you’re an advanced Mac user and you’d like to easily see all running processes and which files, directories, sockets, and pipes are open by those processes, the free Sloth tool may be useful to you. The Sloth app is basically a GUI front-end to lsof, a powerful command line tool that allows you to … Read More
Using the lsof command, we can find out exactly what process or application is using a specified file at that given moment. This is similar to the opensnoop command, but rather than watching the changes to a file over time, lsof can give us a snapshot of this very moment, which can be helpful for … Read More
Using GeekTool and lsof, you can display an automatically updated list of open network connections directly on a Mac OS X desktop. This is tip is a “safe” alternative to the previously mentioned open_ports utility. The problem with installing and using open_ports is that it is a third party script running as root, and for … Read More
Much like you can monitor Mac OS X filesystem usage through the command line, you can also discover what apps and individual processes are currently using your Macs internet connection. This is a really handy trick if you know your bandwidth is being used by something, or if you’re just trying to track down what … Read More
Recently the LAN at my office had been running slower than usual, and I couldn’t pinpoint what was using up all the extra bandwidth. I had a suspicion that P2P traffic was to blame but I just couldn’t see anything obvious on the offending machine. So the question of course, is how do you see … Read More
