Regex Anchors

Anchors Meaning Language
^ Fix regex match to the beginning of a line
$ Fix regex match to the ending of a line
\A Fix regex match to the beginning of a string Ruby
\Z Fix regex match to the ending of a string Ruby
\z Fix regex match up to, but not including, a newline at the end of a string (prefer \Z when possible) Ruby
\b Fix regex match to word boundaries
\B Fix regex match to non-word boundaries

See also Regex Miscellaneous#