Metacharacter What It Matches
^ Matches to beginning of line or beginning of string
$ Matches to end of line or end of a string
\A Matches the beginning of the string only
\Z Matches the end of the string or line
\z Matches the end of string only
\G Matches where previous m//g left off
\b Matches a word boundary (when not inside [ ])
\B Matches a nonword boundary