grep - searches input files for lines containing a match to a given pattern list.
Search all lines in file mp3_list.txt which contains word mozart:
grep mozart mp3_list.txt
Search all lines in file mp3_list.txt which contains word mozart (ignoring case):
grep -i mozart mp3_list.txt
Search all lines in file mp3_list.txt which doesn't contain word beethoven:
grep -v beethoven mp3_list.txt
Count how many lines contains "mozart" has occurred in the file mp3_list.txt:
grep -c mozart mp3_list.txt
Show which lines "mozart" has appeared:
grep -n mozart mp3_list.txt