Sloth

Sloth shows every open file, folder, network socket, pipe and device in use by the processes running on your Mac. It answers questions like which app is holding a file you cannot eject or delete, or which program has a port open.

It is a graphical front end for the lsof command line tool. Results appear in a sortable, searchable outline grouped by process. You can filter by name, access mode, volume, type or location, use regular expressions, and sort by process name, file count, process ID, user ID or bundle identifier.

For IP sockets it shows status, protocol, port and version, and it can show the sockets and pipes that connect two processes. An inspector window gives detailed file, socket and process info, and a contextual menu offers file operations. To see processes owned by other users, authenticate inside the app and scan with root privileges.

Sloth is free and open source under the BSD 3-Clause licence, made by Sveinbjörn Þórðarson and maintained since 2004. The download is about 1.3 MB, signed and notarized, and runs natively on Apple Silicon and Intel with macOS 11 or later.