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regexp(expression)

Instantiates a regular expression object

Availability

Device + Agent

Parameters

Name Type Description
expression String A regular expression

Returns

Regular expression object

Description

This function compiles a regular expression pattern and returns it as a new regexp object.

Important Because of shortcomings in Squirrel’s regexp, we strongly recommend that you implement regular expressions in your agent code using regexp2() as a drop-in replacement for regexp().

Below are the codes that may be used to construct the pattern-matching expression.

Code Operation
\ Quote the next metacharacter
^ Match the beginning of the string
. Match any character
$ Match the end of the string
| Alternation
(subexp) Grouping (creates a capture)
(?:subexp) No capture grouping (no capture)
[] Character class
* Match zero or more times
+ Match one or more times
? Match once or no match
{n} Match exactly n times
{n,} Match at least n times
{n,m} Match at least n times but no more that m times
\l Next character is lower case
\u Next character is upper case
\a Next character is a letter (a-z, A-Z)
\A Next character is not a letter
\w Next character is alphanumeric (a-z, A-Z, 0-9)
\W Next character is non-alphanumeric
\s Next character is a space
\S Next character is not a space
\d Next character is a digit (0-9)
\D Next character is not a digit
\x Next character is a hexadecimal digit (0-F)
\X Next character is not a hexadeximal digit
\c Next character is a control character
\C Next character is not a control character
\p Next character is a punctuation mark
\P Next character is not a punctuation mark
\b Match a character on a word boundary
\B Match a character not a word boundary
\t Match a tab character
\n Match a newline (NL) or linefeed (LF) character
\r Match a carriage return (CR) character
\f Match a formfeed (FF) character

Example Code