Anyone who’s administered a Linux server for a certain amount of time is familiar with the “grep” command. With Linux’s philosophy of “Everything is a file”, grep becomes crucial to traversing log files, configuration files, checking for certain errors in output files, and getting the number of matches. In this tutorial, I’ll show you a few advanced uses of grep that can still be pretty useful. These are not hard to find in the man pages, but they’re just an extension of grep’s default functionality.