NET, PCRE (C, PHP, R…), Perl, Python and Java (but not Ruby), you can use the inline modifier (?s), for instance in (?s)BEGIN. If you've got infinite time on your hands, you can also try porting PCRE to JavaScript using Emscripten, as Firas seems to have done on regex 101. Therefore it matches any character.Īnother JavaScript solution is to use the XRegExp regex library. This character class matches one character that is either a non-digit \D or a digit \d. To match any character in JavaScript, including line breaks, use a construct such as. JavaScript does not support single-line mode. The third option dot-matches-line-breaks is descriptive but a bit of a mouthful.įor several engines, note that there are two ways of turning it on: as an inline modifier or as an option in the regex method or function. To me, the name DOTALL is a sensible way to call this mode. The mode is also called DOTALL in PCRE, Python and Java (to be more precise, the PCRE documentation uses PCRE_DOTALL). * will match from the first character to the last, no matter how many line breaks stand in between. This mode is sometimes called single-line (hence the s) because as far as the dot is concerned, it turns the whole string into one big line. *? END to match across lines, we need to turn that feature on. doesn't match line break characters such as line feeds and carriage returns. For instance, you can use:ĭOTALL (Dot Matches Line Breaks): s (with exceptions)īy default, the dot. For instance, you can use:Īpart from the (?i) inline modifier, Ruby lets you add the i flag after your pattern's closing delimiter. In JavaScript, your only option is to add the i flag after your pattern's closing delimiter. If you're only working with ASCII, you don't have to use it. The UNICODE_CASE option added here ensures that the case-insensitivity feature is Unicode-aware. Note that in PCRE, to use case-insensitive matching with non-English letters that aren't part of your locale, you'll have to turn on Unicode mode-for instance with the (*UTF8) special start-of-pattern modifier.Īpart from the (?i) inline modifier, PCRE lets you set the PCRE_CASELESS mode when calling the pcre_compile() (or similar) function: Var catRegex = new Regex("cat", RegexOptions.IgnoreCase) Īpart from the (?i) inline modifier, Perl lets you add the i flag after your pattern's closing delimiter. NET languages have the IgnoreCase option. See the section on inline modifiers for juicy details about three additional features (unavailable in Python): turning it on in mid-string, turning it off with (?-i), or applying it only to the content of a non-capture group with (?i:foo)Īpart from the (?i) inline modifier. NET, PCRE (C, PHP, R…), Perl, Python, Java and Ruby (but not JavaScript), you can use the inline modifier (?i), for instance in (?i)cat. Even if I knew all the answers, it would be impossible to include them all in this section: if you use a particular script, you'll need to research how your specific engine handles case-insensitive matching in that script.įor several engines, note that there are two ways of turning on case-insensitive matching: as an inline modifier (?i) or as an option in the regex method or function. These questions are just the tip of the iceberg. ✽ Will i match İ (Turkish capital i) as well as I? ✽ Will ß match ss? No engine seems to do so. the letter a and the grave accent) match À? All engines seem to handle that correctly. Here are some questions you may run into. When you branch out into typographical niceties or other languages and scripts, things are not always so simple. If you want patterns such as Name: to match in case-insensitive fashion, we need to turn that feature on.Īs long as you stick to the 26 letters of the English alphabet, the definition of upper-case and lower-case is straightforward. ✽ PCRE's Special Start-of-Pattern Modifiersīy default, all major regex engines match in case-sensitive mode. ✽ Multiline ( ^ and $ Match on Every Line): m (except Ruby) ✽ DOTALL (Dot Matches Line Breaks): s (except Ruby and JavaScript) The final section briefly surveys other modifiers, which are usually language-specific.įor easy navigation, here are some jumping points to various sections of the page: Rather than repeatedly explain what they do and the multiple ways to turn them on in every regex flavor, I decided to gather the four common ones ( i, s, m and x) in one place. Regex modifiers turn up at every corner on this site. This is a reference page-don't feel you have to read it as it is rather terse.
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