# Regular Expression Metacharacters

Note that in addition to the standard metacharacters described in the table, Yate supports \V# and \<named variable> sequences via a prescan to insert the contents of a Variable or named variable. The inserted contents can be treated as literal characters or can be escaped to ensure that they do not interfere with any of the standard sequences.

Character | Description
--- | ---
\a | Match a BELL, \u0007
\A | Match at the beginning of the input. Differs from ^ in that \A will not match after a new line within the input.
\b | Match if the current position is a word boundary. Boundaries occur at the transitions between word (\w) and non-word (\W) characters, with combining marks ignored..
\B | Match if the current position is not a word boundary.
\cX | Match a control-X character.
\d | Match any character with the Unicode General Category of Nd (Number, Decimal Digit.)
\D | Match any character that is not a decimal digit.
\e | Match an ESCAPE, \u001B.
\E | Terminates a \Q ... \E quoted sequence.
\f | Match a FORM FEED, \u000C.
\G | Match if the current position is at the end of the previous match.
\n | Match a LINE FEED, \u000A.
\N{UNICODE CHARACTER NAME} | Match the named character.
\p{UNICODE PROPERTY NAME} | Match any character with the specified Unicode Property.
\P{UNICODE PROPERTY NAME} | Match any character not having the specified Unicode Property.
\Q | Quotes all following characters until \E.
\r | Match a CARRIAGE RETURN, \u000D.
\s | Match a white space character. White space is defined as [\t\n\f\r\p{Z}].
\S | Match a non-white space character.
\t | Match a HORIZONTAL TABULATION, \u0009.
\uhhhh | Match the character with the hex value hhhh.
\Uhhhhhhhh | Match the character with the hex value hhhhhhhh. Exactly eight hex digits must be provided, even though the largest Unicode code point is \U0010ffff.
\w | Match a word character. Word characters are [\p{Alphabetic}\p{Mark}\p{Decimal_Number}\p{Connector_Punctuation}\u200c\u200d].
\W | Match a non-word character.
\x{hhhh} | Match the character with hex value hhhh. From one to six hex digits may be supplied.
\xhh | Match the character with two digit hex value hh
\X | Match a Grapheme Cluster.
\Z | Match if the current position is at the end of input, but before the final line terminator, if one exists.
\z | Match if the current position is at the end of input.
\n | Back Reference. Match whatever the nth capturing group matched. n must be a number > 1 and < total number of capture groups in the pattern.
\0ooo | Match an Octal character. 'ooo' is from one to three octal digits. 0377 is the largest allowed Octal character. The leading zero is required; it distinguishes Octal constants from back references.
[pattern] | Match any one character from the pattern. The pattern can contain ranges. [a-zA-Z0-9] implies all letters and digits.
[^pattern] | Match any one character not in the pattern. The pattern can contain ranges. [^a-zA-Z0-9] implies any character except letters and digits.
. | Match any character.
^ | Match at the beginning of a line.
$ | Match at the end of a line.
\ | Quotes the following character. Characters that must be quoted to be treated as literals are: * ? + [ ( ) { } ^ $ | \ .

Regular Expression Operators

Regular Expression Replace Template Format

Regular Expression Flag Options