Bug #10666 [Com]: preg_replace 'e' modifier

Edit report at https://bugs.php.net/bug.php?id=10666&edit=1 ID: 10666 Comment by: raincious at gmail dot com Reported by: smoonen at andstuff dot org Summary: preg_replace 'e' modifier Status: Closed Type: Bug Package: PCRE related Operating System: Linux PHP Version: 4.0.5 Block user comment: N Private report: N New Comment: NO, this just IS A BUG. Please fix it or add a switch to shutdown the bug, i don't need it done any other thing for me without replace then call the function. I know someone want to be perfect, but it's overplayed. If you want to do everything for user, why don't just pay time for create a function php, named give_me_my_wanted_website();? Previous Comments: ------------------------------------------------------------------------ [2004-08-23 16:49:31] info at webprog dot de 3 Years ago its allready a feature? :-) I build something like this: $r = "<span lang=\"en\" xml:lang=\"en\">".$words."</span>"; $this->template = preg_replace ("/((<[^>]*)|(^| |>)($words)([^a-zA-Z]|$))/e", '"\\2"=="\\1"? "\\1":"\\3<span lang=\"en\" xml:lang=\"en\">\\4</span>\\5"', $this->template); ...and it works fine with Perl and bad with PHP, because it sets in front of every single quote a backslash. ------------------------------------------------------------------------ [2001-08-03 12:01:46] smoonen at andstuff dot org Strangely, while the bug referenced in my update at [2001-05-04 13:55:39] was very repeatable across several PHP installations, I can no longer duplicate it. Am closing the bug, though in my dreams I still wish for $n pseudovariables. ;-) ------------------------------------------------------------------------ [2001-05-04 14:36:12] smoonen at andstuff dot org Also, as a merely informational aside, PHP's use of $1 is in this instance actually incompatible with Perl. Perl, in a s///e expression, treats $n as a variable rather than expanding it in-place. Hence my preference. :-) ------------------------------------------------------------------------ [2001-05-04 13:55:39] smoonen at andstuff dot org Okay. Then I have a problem with how backslash escaping is inconsistently applied when using \\1 and $1. Specifically, consider the following: function f($x) { print $x; } $s = "a' \\ \"b"; $s = preg_replace('/a(.*)b/e', 'f("$1")', $s, -1); The single quote is escaped; I'd rather it weren't but that's okay. But the backslash itself isn't escaped! This prevents me from running stripslashes() on the match, since I can't guarantee that every backslash has been properly escaped. Worse, the following will actually fail: function f($x) { print $x; } $s = "a' \" \\b"; $s = preg_replace('/a(.*)b/e', 'f("$1")', $s, -1); Since the final backslash hasn't been escaped, it actually slurps up the second double-quote in 'f("$1")'! I'd like to see either of the following: 1. $1 treated as a "real" variable, rather than a string substitution. This is convenient, since it saves me having to call stripslashes(). 2. Backslash escapes consistently applied in backrefs. Specifically, escape existing backslashes in the match. Presently, I can't perform a stripslashes() -- and in some cases, as indicated above, it fails altogether! ------------------------------------------------------------------------ [2001-05-04 13:02:59] andrei@php.net $n notation was introduced to be similar to Perl. It is exactly equivalent to \\n. You can't simply use f($1) in the evaluation string because $1 is replaced with the matched contents and after replacement it becomes, in your example, f(abc def), which is not valid PHP code. So you have to use f("$1") or f('$1'). The fact that it backslash-escapes single and double quotes in matches before substituting $1 is a feature, not a bug, otherwise you'd have a really hard time figuring out which quotes go where when using evaluation strings. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=10666 -- Edit this bug report at https://bugs.php.net/bug.php?id=10666&edit=1