Regular expressions can be used in
conjunction with a number of VCS features
such as alias transformations, zone
transformations, CPL policy and ENUM. The
VCS uses POSIX format regular expression
syntax.
This section provides a list of commonly
used special characters in regular expression
syntax.

Character Description

Example

Matches any character.

Matches 0 or more repetitions of the previous
match.

will match against any sequence of characters.

Matches 1 or more repetitions of the previous
match.

Escapes a regular expression special character.

Matches any decimal digit, i.e. 0-9.

[...]

Matches a set of characters. Each character in
the set can be specified individually, or a range
can be specified by giving the first character in
the range followed by the

character and then the

last character in the range.
You can not use special characters within the

[]

- they will be taken literally.

[a-z]

will match against any lower case alphabetical character.

[a-zA-Z]

will match against any alphabetical character.

[0-9#*]

will match against any single E.164 character - the E.164 character set is

made up of the digits

0-9 plus the hash key (#) and the asterisk key (*).

(...)

Groups a set of matching characters together.
Groups can then be referenced in order using the
characters

, etc. as part of a replace string.

A regular expression can be constructed to transform a URI containing a user’s full
name to a URI based on their initials.
The regular expression

(.).* _ (.).*(@example.com)

would match against the

user

john _ smith@example.com

and with a replace string of

\1\2\3

would

transform it to

js@example.com

Matches against one expression or an alternate
expression.

.*@example.(net|com)

will match against any URI for the domain

example.com

or the domain

example.net

Signifies the start of a line.

Signifies the end of a line.

^\d\d\d$

will match any string that is exactly 3 digits long.

(?!...)

Negative lookahead. Defines a subexpression
that must not be present in order for there to be
a match.

(?!.*@tandberg.net$).*

will match any string that does not end with

@tandberg.net

For an example of regex usage, see

CPL Examples

For a detailed description of regular

expression syntax see [