egrep

Linux grep FAQ: How can I perform a recursive search with the Linux grep command?

For years I've always used variations of the following Linux find and grep commands to recursively search subdirectories for files that match my grep pattern:

Summary: How to use the Linux egrep command with multiple regular expressions (regex patterns).

As a quick note here today, I just used the Linux egrep command to perform a case-insensitive search on multiple regular expressions (regex patterns). Really, what I did was a little more complicated:

locate -i calendar | grep Users | egrep -vi 'twiki|gif|shtml|drupal-7|java|PNG'

As you can see from that command, I did this:

Problem

You need to reverse the meaning of a search you're performing with the grep command. For instance, you've been searching for pepperoni pizza orders like this:

grep pepperoni pizza-orders.txt

and now you need to find all orders that don't have pepperoni.

Solution

Just add the -v switch to your grep search command, like this: