ADC

Operations for regular expressions

July 14, 2021

Contributed by:

S S

The following table describes the operators that work with regular expressions. The operation performed by a regular expression operator in a given Advanced policy expression depends on whether the expression prefix identifies text or HTTP headers. Operations that evaluate headers override any text-based operations for all instances of the specified header type. When you use an operator, replace <text> with the Advanced policy expression prefix that you want to configure for identifying text.

Regular Expression Operation	Description
.BEFORE_REGEX()	Selects the text that precedes the string that matches the argument. If the regular expression does not match any data in the target, the expression returns a text object of length 0. The following expression selects the string "text" from "text/plain". http.res.header("content-type").before_regex(re#/#)
.AFTER_REGEX()	Selects the text that follows the string that matches the argument. If the regular expression does not match any text in the target, the expression returns a text object of length 0. The following expression extracts "Example" from "myExample": http.req.header("etag").after_regex(re/my/)
.REGEX_SELECT()	Selects a string that matches the argument. If the regular expression does not match the target, a text object of length 0 is returned. The following example extracts the string "NS-CACHE-9.0: 90" from a Via header: http.req.header("via").regex_select(re!NS-CACHE-\d.\d:\s*\d{1,3}!)
.REGEX_MATCH()	Returns TRUE if the target matches a argument of up to 1499 characters. The regular expression must be of the following format: reregular expression< delimiter> Both delimiters must be the same. Additionally, the regular expression must conform to the Perl-compatible (PCRE) regular expression library syntax. For more information, go to http://www.pcre.org/pcre.txt. In particular, see the pcrepattern man page. However, note the following: Back-references are not allowed. Recursive regular expressions are not recommended. The dot metacharacter also matches the newline character. The Unicode character set is not supported. SET_TEXT_MODE(IGNORECASE) overrides the (?i) internal option specified in the regular expression. The following are examples: http.req.hostname.regex_match(re/[[:alpha:]]+(abc){2,3}/) and http.req.url.set_text_mode(urlencoded).regex_match(re#(ab+c)#) The following example matches ab and aB: http.req.url.regex_match(re/a(?i)b/) The following example matches ab, aB, Ab and AB: http.req.url.set_text_mode(ignorecase).regex_match(re/ab/) The following example performs a case-insensitive, multiline match in which the dot meta-character also matches a newline character: http.req.body.regex_match(re/(?ixm) (^ab (.*) cd$) /)

The official version of this content is in English. Some of the Cloud Software Group documentation content is machine translated for your convenience only. Cloud Software Group has no control over machine-translated content, which may contain errors, inaccuracies or unsuitable language. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, suitability, or correctness of any translations made from the English original into any other language, or that your Cloud Software Group product or service conforms to any machine translated content, and any warranty provided under the applicable end user license agreement or terms of service, or any other agreement with Cloud Software Group, that the product or service conforms with any documentation shall not apply to the extent that such documentation has been machine translated. Cloud Software Group will not be held responsible for any damage or issues that may arise from using machine-translated content.

Was this helpful

Operations for regular expressions

July 14, 2021

Contributed by:

S S

July 14, 2021

Contributed by:

S S

Operations for regular expressions

In this article