pcre

Regular expression – PCRE does not support \L, \l, \N, \P,

by

PCRE does not support the \uXXXX syntax. Use \x{XXXX} instead. See here. Your \u2e80-\u9fff range is also equivalent to \p{InCJK_Radicals_Supplement}\p{InKangxi_Radicals}\p{InIdeographic_Description_Characters}\p{InCJK_Symbols_and_Punctuation}\p{InHiragana}\p{InKatakana}\p{InBopomofo}\p{InHangul_Compatibility_Jamo}\p{InKanbun}\p{InBopomofo_Extended}\p{InKatakana_Phonetic_Extensions}\p{InEnclosed_CJK_Letters_and_Months}\p{InCJK_Compatibility}\p{InCJK_Unified_Ideographs_Extension_A}\p{InYijing_Hexagram_Symbols}\p{InCJK_Unified_Ideographs} Don’t forget to add the u modifier (/regex here/u) if you’re dealing with UTF-8. If you’re dealing with another multi-byte encoding, you must first convert it to UTF-8.

Perl compatible regular expression (PCRE) in Python

by

Be Especially Careful with non‐ASCII in Python There are some really subtle issues with how Python deals with, or fails to deal with, non-ASCII in patterns and strings. Worse, these disparities vary substantially according, not just to which version of Python you are using, but also whether you have a “wide build”. In general, when … Read more

PCRE Regex to SED

by

Want PCRE (Perl Compatible Regular Expressions)? Why don’t you use perl instead? perl -pe ‘s/[a-zA-Z0-9]+[@][a-zA-Z0-9]+[\.][A-Za-z]{2,4}/[emailaddr]/g’ \ <<< “My email is abc@example.com” Output: My email is [emailaddr] Write output to a file with tee: perl -pe ‘s/[a-zA-Z0-9]+[@][a-zA-Z0-9]+[\.][A-Za-z]{2,4}/[emailaddr]/g’ \ <<< “My email is abc@example.com” | tee /path/to/file.txt > /dev/null

What’s the technical reason for “lookbehind assertion MUST be fixed length” in regex?

by

Lookahead and lookbehind aren’t nearly as similar as their names imply. The lookahead expression works exactly the same as it would if it were a standalone regex, except it’s anchored at the current match position and it doesn’t consume what it matches. Lookbehind is a whole different story. Starting at the current match position, it … Read more

Linker error LNK2038: mismatch detected in Release mode

by

Your app is being compiled in release mode, but you’re linking against the debug version of PCRE, which had /MTd (or similar) set, thus causing the mismatch in iterator debugging level in the CRT. Recompile PCRE in release mode to match your own application. The detect_mismatch pragma in VS 2010 is what causes this error … Read more

Match a^n b^n c^n (e.g. “aaabbbccc”) using regular expressions (PCRE)

by

Inspired by NullUserExceptions answer (which he already deleted as it failed for one case) I think I have found a solution myself: $regex = ‘~^ (?=(a(?-1)?b)c) a+(b(?-1)?c) $~x’; var_dump(preg_match($regex, ‘aabbcc’)); // 1 var_dump(preg_match($regex, ‘aaabbbccc’)); // 1 var_dump(preg_match($regex, ‘aaabbbcc’)); // 0 var_dump(preg_match($regex, ‘aaaccc’)); // 0 var_dump(preg_match($regex, ‘aabcc’)); // 0 var_dump(preg_match($regex, ‘abbcc’)); // 0 Try it yourself: … Read more

Invert match with regexp [duplicate]

by

Okay, I have refined my regular expression based on the solution you came up with (which erroneously matches strings that start with ‘test’). ^((?!foo).)*$ This regular expression will match only strings that do not contain foo. The first lookahead will deny strings beginning with ‘foo’, and the second will make sure that foo isn’t found … Read more

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)