--- title: Bash Grep --- ## Bash command: grep `grep` stands for Global Regular Expression Print. It is used to search piped input or files for a string which can contain regex. ### Usage ``` grep ``` Commonly used options: * `-i` - Ignores the case when performing the search. * `-v` - Inverts the search and only selects lines that do not match the search string. ### Examples #### Search for IP 127.0.0.1 in the /etc/hosts file ```bash grep "127.0.0.1" /etc/hosts ``` #### Search for oom (out of memory) in /var/log/messages ```bash grep -i oom /var/log/messages ``` ### More Information * run `man grep` for a full list of available flags/options to use. * [Wikipedia](https://en.wikipedia.org/wiki/Grep)