OS X Tools: All you really need to know about GREP

Ever need to look through an endless file list to determine if a certain file is there? Cross-eyed from looking at a ps listing to find the one program you want to kill? You need grep.

And if you’re on a Mac (or a Unix/Linux machine) you’re in luck.

There’s a million ways to use grep, but this one will quickly show you how powerful it is (and it’s probably all you need to know).

Suppose you need to shutdown a particular program… one that doesn’t show up on the Activity Monitor. You open the Terminal application, type “ps -A” and watch in awe as a million lines shoot by your screen, trying to figure out which one corresponds to the program you wish to kill.

Instead, try this the next time:

Let’s pretend you need to shutdown a particular application that’s not responding (or doesn’t have a Quit option). I’ll use mozy as an example. Instead of going line-by-line looking for the one that includes mozy, you simply type this command:

ps -A | grep -i mozy

and you’ll get the following back:

24293 ?? Ss 0:03.52 /usr/sbin/MozyBackup

24449 p2 R+ 0:00.00 grep -i mozy

Now all you need to do is issue the following command:

sudo kill 24293

to shutdown the application.

What you’re doing is simply taking the result of the “ps -A” command and sending it, using the ”|” operator, to the grep utility, which will search for any occurrences of the phrase “mozy” (the -i option makes the search case insensitive).

Do you have any other uses for grep? Any other useful utilities? Leave your comment below.