Info Catalog grep: The Backslash Character and Special Expressions grep: Regular Expressions grep: Back-references and Subexpressions

grep: Anchoring

 
 3.4 Anchoring
 =============
 
 The caret ‘^’ and the dollar sign ‘$’ are special characters that
 respectively match the empty string at the beginning and end of a line.
 They are termed “anchors”, since they force the match to be “anchored”
 to beginning or end of a line, respectively.
 

Info Catalog grep: The Backslash Character and Special Expressions grep: Regular Expressions grep: Back-references and Subexpressions