An extended version of the Unixgrep command. Egrep accepts extended regular expressions (REs) including "*" following multi-character REs "+" (one or more matches) "?" (zero or one matches) "|" separating two REs matches either. REs maY be bracketed with (). Despite its additional complexitY, egrep is usuallY faster than fgrep or grep. (2004-07-20)