Bug #68310 [Nab]: preg_split() fail with extended modifier

Edit report at https://bugs.php.net/bug.php?id=68310&edit=1 ID: 68310 User updated by: david dot proweb at gmail dot com Reported by: david dot proweb at gmail dot com Summary: preg_split() fail with extended modifier Status: Not a bug Type: Bug Package: PCRE related Operating System: Irrelevant PHP Version: 5.5.18 Block user comment: N Private report: N New Comment: Relly, Nikic, you are right. I confused with \w and \s, but both not is converted in double-quoted string and, how it is not occur, preg_split can use it as it is. \s => \s \w => \w \r => return feed (that is ignored by /x modifier) \n => new line (that is ignored by /x modifier) What I can do for this case is: - Option 1: convert to single-quoted string; - Option 2: double-escape this characters; - Option 3: encapsulate characters in class like [\r] and [\n]; I reported this problem because in PHP 4.x, the problem does not occur. But I can imagine that the /x modifier has changed to become more logical, as you said. Previous Comments: ------------------------------------------------------------------------ [2014-10-27 15:02:08] nikic@php.net Double-quoted string interpret escape sequences, so what PCRE actually sees are the strings like "/ ? /" (where the first newline is supposed to be an \r and the second one an \r. So you can either escape the backslash (as you did) or use single-quoted strings like '/\r?\n/'. ------------------------------------------------------------------------ [2014-10-27 13:18:53] david dot proweb at gmail dot com Description: ------------ preg_split(pattern, subject) will fail if I use a pattern with extended (/x) modifier with escaped sequences (like \r or \n), but if I double escape it, it'll work. Seems a bug for me. If I do: /\r?\n/ over "abc\r\n123" it will split to ["abc", "123"]. If I do: /\r?\n/x over "abc\r\n123" it will will fail¹. If I do: /\\r?\\n/x over "abc\r\n123" it will split to ["abc", "123"]. If you repair, I need to escape twice when I use /x modifier. It doesn't occur if I use preg_match(pattern, subject). PHP 4.x it'll works correctly. ¹ Compilation failed: nothing to repeat at offset 1. Test script: --------------- $split_normal = "/\r?\n/"; $split_extended_escaped = "/\r?\n/x"; $split_extended_reescaped = "/\\r?\\n/x"; $split_text = "abc\r\n123"; var_dump(preg_split($split_normal, $split_text)); // OK var_dump(preg_split($split_extended_escaped, $split_text)); // Wrongly FAIL var_dump(preg_split($split_extended_reescaped, $split_text)); // Wrongly OK ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=68310&edit=1