xxxxxxxxxx
# Basic syntax:
grep 'word1\|word2\|word3' /path/to/file
# This prints all lines that match word1, word2, OR, word3
xxxxxxxxxx
# Basic syntax:
grep first_word input_file | grep second_word
# Where:
# - 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.