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Diffstat (limited to 'source/rainerscript/functions/rs-re_extract.rst')
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diff --git a/source/rainerscript/functions/rs-re_extract.rst b/source/rainerscript/functions/rs-re_extract.rst new file mode 100644 index 0000000..cd37910 --- /dev/null +++ b/source/rainerscript/functions/rs-re_extract.rst @@ -0,0 +1,38 @@ +************ +re_extract() +************ + +Purpose +======= + +re_extract(expr, re, match, submatch, no-found) + +Extracts data from a string (property) via a regular expression match. +POSIX ERE regular expressions are used. The variable "match" contains +the number of the match to use. This permits to pick up more than the +first expression match. Submatch is the submatch to match (max 50 supported). +The "no-found" parameter specifies which string is to be returned in case +when the regular expression is not found. Note that match and +submatch start with zero. It currently is not possible to extract +more than one submatch with a single call. + +This function performs case-sensitive matching. Use the otherwise-equivalent +:doc:`re_extract_i <rs-re_extract_i>` function to perform case-insensitive +matches. + +.. note:: + + Functions using regular expressions tend to be slow and other options + may be faster. + + +Example +======= + +In the following example the msg object is checked for the regex string. +Only the first match is used and if no match was found an empty string is returned. + +.. code-block:: none + + re_extract($msg,'(5[1-5][0-9]{14})',0,1,"") + |