NAME
grep, egrep, fgrep - print lines matching a pattern
SYNOPSIS
grep [options] PATTERN [FILE...]
grep [options] [-e PATTERN | -f FILE] [FILE...]
DESCRIPTION
Grep searches the named input FILEs (or standard input if no files are named, or the file name - is
given) for lines containing a match to the given PATTERN. By default, grep prints the matching lines.
In addition, two variant programs egrep and fgrep are available. Egrep is the same as grep -E. Fgrep
is the same as grep -F.
http://bashconsole.org/man.1.grep