This expression is the opposite of the positive assertion it succeeds if the contained expression doesn't match at the current position in the string. System (?= root) matches the word system only when followed by the word root. , successfully matches at the current location, and fails otherwise. This expression succeeds if the contained regular expression, represented here by. (?=(system|root))(\w+) matches the words system or root.
WIN(\w)(\w)$ matches WINXP, WIN98 but not WINDOWS This group is called alphanumeric characters (). The underscore character matches the first. Matches only one character, "\w" stands for any letter or the underscore character. This forces it to stop matching at the first underscore, rather than the last. Matches only one decimal digit this expression is equivalent to the class. ?at matches the strings cat, rat, bat but not flat Matches 0 or 1 occurrence of the character or regular expression immediately preceding. Matches one or more occurrences of the character or regular expression immediately preceding. (the man|the woman) matches the lines "it belongs to the man" and "it belongs to the woman" but not the line "it belongs to them." \
The pattern matching is very similar to the pattern matching in Perl.Ī full installation of Perl will include plenty of documentation on regular expressions - look for perlrequick, Alternatives occur when the expression can match either one sub. OROMatcher User's guide, which might prove useful. (abc) matches zero characters only if they are not followed by the expression abc. There is also documentation on an older incarnation of the product at There is some documentation for this on the Jakarta web-site, for exampleĪ summary of the pattern matching characters
JMeter includes the pattern matching software Apache Jakarta ORO