Linux Shell Scripting Cookbook - Third Edition

Position markers

A position marker anchors a regular expression to a position in the string. By default, any set of characters that match a regular expression can be used, regardless of position in the string.

regex	Description	Example
^	This specifies that the text that matches the regular expression must start at the beginning of the string	^tux matches a line that starts with tux
$	This specifies that the text that matches the regular expression must end with the last character in the target string	tux$ matches a line that ends with tux