Regular Expressions and Character Sets

\

Backslash

escape metacharacters

non-printable characters

character types

[ ]

Square Brackets

character class definition

( )

Parenthesis

sub-pattern, to use metacharacters on the enclosed string

{min[,max]}

Curly Brackets

min/max quantifier

{n} - exactly n occurrences

{n,m} - from n to m occurrences

{n,} - at least n occurrences

.

Dot

match any character

?

Question Mark

zero or one occurrences (equals {0,1})

*

Asterisk

zero or more occurrences of preceding character

+

Plus Sign

one or more occurrences (equals {1,})

|

Vertical Bar

alternative

^

Circumflex

anchor pattern to beginning of buffer (usually a word)

$

Dollar

anchor pattern to end of buffer (usually a word)

-

hyphen

range in character class