How To Search Multiple Words / String Pattern Using grep Command on Bash shell

To search for multiple words or a string pattern using the grep command on Bash, a Unix shell and command language, you can use regular expressions or special characters such as | and ().

Here is an example of how to use regular expressions to search for multiple words with grep:

grep 'word1\|word2\|word3' file.txt

This command searches for any lines in the file.txt file that contain the words word1, word2, or word3. The \| symbol acts as an "or" operator, allowing you to specify multiple words to search for.

You can also use parentheses to group words and use the | symbol as an "or" operator. For example:

grep '(word1|word2) word3' file.txt

This command searches for lines in the file.txt file that contain either word1 or word2 followed by word3.

By using regular expressions or special characters such as | and (), you can search for multiple words or a string pattern using the grep command on Bash. It's always a good idea to carefully review the documentation and use the appropriate syntax when working with regular expressions. This will help ensure that your search is accurate and efficient.