egrep - extends grep to handle ranges [1]
Syntax: ‘(regular expression [range])’
egrep '(c|5)' home-on-the-range to find lines that have “c” or “5”
egrep '(^[hi])' home-on-the-range to find lines that begin with “h” or “i”
egrep '(^[^46])' home-on-the-range to find lines that do not begin with “4”, “5”, or “6”