grep multiple string code example

Example 1: bash print lines that match any of several words

# Basic syntax:
grep 'word1\|word2\|word3' /path/to/file
# This prints all lines that match word1, word2, OR, word3

Example 2: bash print lines that contain multiple specific words

# Basic syntax:
grep first_word input_file | grep second_word
# This finds all lines that contain the first_word and then pipes them
# to a second filter that looks for the second_word, resulting in all
# lines that contain both words. Simply add more pipes and greps to 
# return lines that meet other search criteria.