July 20, 2023

Search multiple files for an expression (e.g. a keyword) with grep

You can search the content of multiple files for a pattern, that is a keyword for example, and show the list of files which match that pattern to the shell with the utility grep.

The syntax of the command is:

$ grep pattern file.s

For example:

$ grep hello file.txt

will print the lines of the file file.txt where there is an occurence of hello.

$ grep hello *

will print the lines and names of the files in the current directory which content matches hello.

You can also pass option to grep. For example:

$ grep -i hello *

will print the lines and names of files which content matches hello or HELLO.

$ grep -r hello *

will search directories recursively in addition to files in the current directory and print the lines and names of files which content matches hello.

$ grep -d skip hello *

$ grep -d s hello *

will print the lines and names of files in the current directory which content matches hello and skip directories.

$ grep -i hello *.md

will print the lines and names of files ending with extension .md in the current directory which content matches hello or HELLO.

$ grep '^Tags:.*grep$' *

will print the lines and name of files which content matches a sentence which both starts with ‘Tags:’ and end with the term ‘grep’.

To learn more about grep and regular expressions see the many more options run $ man grep.

grep is copyleft-licensed and is maintained by Jim Meyering¹. It was first released in 1973.