Linux in a Nutshell, Fourth Edition

Metacharacters

The following characters have special meaning in search patterns:

Character	Action
.	Match any single character except newline.
*	Match any number (or none) of the single character that immediately precedes it. The preceding character also can be a regular expression (e.g., since . (dot) means any character, .* means match any number of any character—except newlines).
^	Match the beginning of the line or string.
$	Match the end of the line or string.
[ ]	Match any one of the enclosed characters. A hyphen (-) indicates a range of consecutive characters. A circumflex (^) as the first character in the brackets reverses the sense: it matches any one character not in the list. A hyphen or close bracket (]) as the first character is treated as a member of the list. All other metacharacters are treated as members of the list.
[^ ]	Match anything except enclosed characters.
\{ n,m \}	Match a range of occurrences of the single character that immediately precedes it. The preceding character also can be a regular expression. \{ n \} matches exactly n occurrences, \{ n ,\} matches at least n occurrences, and \{ n,m \} matches any number of occurrences between n and m.
{ n,m }	Like \{ n,m \}. Available in grep by default and in gawk with the -Wre-interval option.
\	Turn off the special meaning of the character that follows.
\( \)	Save the matched text enclosed between \( and \) in a special holding space. Up to nine patterns can be saved ...