Source: 📖 Test Driven Development with Python ch14 p243

Using grep in the command line

The grep command can be used to search for text in a file. It uses the syntax grep <search query> <path to file(s)>.

$ grep 'search for this' in/this/file.txt

It can be combined with other common bash commands, such as the * wildcard.

$ grep 'search for this' in/this/*.txt

The above command will search for the query in all .txt files contained in the this directory.

To search recursively, i.e. to search through all files under a directory and its sub-directories, use the -r option:

$ grep -r 'search for this' in/

Use the -i option to ignore case:

$ grep -r -i 'SeArCh FoR tHiS' in/