Although the u modifier makes both the pattern and subject be interpreted as UTF-8, the captured offsets are still counted in bytes. You can use mb_strlen to get the length in UTF-8 characters rather than bytes: $str = “\xC2\xA1Hola!”; preg_match(‘/H/u’, $str, $a_matches, PREG_OFFSET_CAPTURE); echo mb_strlen(substr($str, 0, $a_matches[0][1]));
1. Download PCRE from PCRE.org 2. Compile it with a prefix and install it: ./configure –prefix=/usr/local/pcre make make install 3. Go back to where your Apache installation is and compile Apache with PCRE: –with-pcre=/usr/local/pcre
I know this isn’t exactly an answer to your question, but it’s helpful to have it here: Regular Expression to match valid XML Characters: [\u0009\u000a\u000d\u0020-\uD7FF\uE000-\uFFFD] So to remove invalid chars from XML, you’d do something like // filters control characters but allows only properly-formed surrogate sequences private static Regex _invalidXMLChars = new Regex( @”(?<![\uD800-\uDBFF])[\uDC00-\uDFFF]|[\uD800-\uDBFF](?![\uDC00-\uDFFF])|[\x00-\x08\x0B\x0C\x0E-\x1F\x7F-\x9F\uFEFF\uFFFE\uFFFF]”, RegexOptions.Compiled); … Read more
TL;DR: Yes, it indeed is possible (use with Jx flags): (?(DEFINE) (?<add> \s*\+\s* ) (?<eq> \s*=\s* ) (?<carry> (?(cl)(?(cr)|\d0)|(?(cr)\d0|(*F))) ) (?<digitadd> (?(?= (?(?= (?(l1)(?(r1)|(*F))|(?(r1)(*F))) )(?&carry)|(?!(?&carry))) )1|0) ) (?<recursedigit> (?&add) 0*+ (?:\d*(?:0|1(?<r1>)))? (?(ro)|(?=(?<cr>1)?))\k<r> (?&eq) \d*(?&digitadd)\k<f>\b | (?=\d* (?&add) 0*+ (?:\k<r>(?<ro>)|\d*(?<r>\d\k<r>)) (?&eq) \d*(?<f>\d\k<f>)\b) \d(?&recursedigit) ) (?<checkdigit> (?:0|1(?<l1>)) (?=(?<cl>1)?) (?<r>) (?<f>) (?&recursedigit) ) (?<carryoverflow> (?<x>\d+) 0 (?<y> \k<r> … Read more
This is the way lexers work. The regular expressions are converted into a single non deterministic automata (NFA) and possibily transformed in a deterministic automata (DFA). The resulting automaton will try to match all the regular expressions at once and will succeed on one of them. There are many tools that can help you here, … Read more
“Non-capturing” doesn’t mean that the group isn’t part of the match; it means that the group’s value isn’t saved for use in back-references. What you are looking for is a look-behind zero-width assertion: grep -Po “(?<=syntaxHighlighterConfig\.)[a-zA-Z]+Color” file
In this case, it’s just being used as a delimiter. Generally, in PHP, the first and last characters of a regular expression are “delimiters” to mark the start and ending position of a matching portion (in case you want to add modifiers at the end, like ungreedy, etc) Generally PHP works this out from the … Read more
Answer to question 1 To answer the first question one could use: (?xm) # ignore comments and whitespace, ^ matches beginning of line ^ # beginning of line (?: . # any character except \n (?= # lookahead .*+\n # go to next line ( \1?+ . ) # add a character to the 1st … Read more
pip install uwsgi -I Won’t recompile the uwsgi binary, it just reinstalls the python egg. You need to rebuild the uwsgi binary with the pcre libraries. sudo apt-get install libpcre3 libpcre3-dev I think the easiest way is just to uninstall uwsgi and then run the pip installer again. pip uninstall uwsgi sudo apt-get remove uwsgi … Read more
PHP regex strings need delimiters. Try: $numpattern=”/^([0-9]+)$/”; Also, note that you have a lower case o, not a zero. In addition, if you’re just validating, you don’t need the capturing group, and can simplify the regex to /^\d+$/. Example: http://ideone.com/Ec3zh See also: PHP – Delimiters