PHP preg match with line ends in Linux and Windows

Question

This code works on Linux but fails to match on Windows:

if ( preg_match ( "~<meta name='date' content='(.*)'>\n<meta name='time' content='(.*)'>\n<meta name='venue' content='(.*)'>\n~", file_get_contents($filename), $matches) ) 
...

I guess the line end coding is wrong. How should I modifiy the pattern to be end-coding independent?

xml/html + regex = [BAD](http://stackoverflow.com/a/1732454/118068). Use DOM instead. it'll also free you from worrying about linebreak characters. — Marc B, Jan 07 '12 at 03:54
Thanks, but DOM cannot give precisely same match behaviour and I cannot afford change. If 100% back-compatibility were not required, yes I would use DOM. — ChrisJJ, Jan 07 '12 at 04:27

score 1 · Accepted Answer · edited Sep 12 '12 at 18:57

Windows line endings are:

   "\r\n"

The simplest solution is:

if (preg_match ("~<meta name='date' content='(.*)'>\n<meta name='time' content='(.*)'>\n<meta name='venue' content='(.*)'>\n~", file_get_contents($filename), $matches)
  ||
  preg_match("~<meta name='date' content='(.*)'>\r\n<meta name='time' content='(.*)'>\r\n<meta name='venue' content='(.*)'>\r\n~", file_get_contents($filename), $matches))

The correct solution probably is:

if (preg_match("~<meta name='date' content='(.*)'>[\r]?\n<meta name='time' content='(.*)'>[\r]?\n<meta name='venue' content='(.*)'>[\r]?\n~", file_get_contents($filename), $matches))

That said, you probably really should use another method for dealing with HTML & XML. There are parsers built specifically for that.

e.g. http://docs.php.net/manual/en/domdocument.loadhtml.php or http://php.net/manual/en/book.xml.php

On a side note, I haven't really tested either but iirc, they work. Regex is not something I use much.

EDIT: Seems to work fine?

$file = "iorahgjajgasjgasjgasjgjaagaspokadsfgals<meta name='date'   content='(.*)'>\n<meta name='time' content='(.*)'>\n<meta name='venue' content='(.*)'>\niorahgjajgasjgasjgasjgjaagaspokadsfgals";

if (preg_match("~<meta name='date' content='(.*)'>\n<meta name='time' content='(.*)'>\n<meta name='venue' content='(.*)'>\n~", $file, $matches)
  || preg_match ("~<meta name='date' content='(.*)'>\r\n<meta name='time' content='(.*)'>\r\n<meta name='venue' content='(.*)'>\r\n~", file, $matches)) { 
  echo "Success";
}
else { 
  echo "Fail";
}

$file = "iorahgjajgasjgasjgasjgjaagaspokadsfgals<meta name='date' content='(.*)'>\r\n<meta name='time' content='(.*)'>\n<meta name='venue' content='(.*)'>\r\niorahgjajgasjgasjgasjgjaagaspokadsfgals";

if (preg_match ("~<meta name='date' content='(.*)'>[\r]?\n<meta name='time' content='(.*)'>[\r]?\n<meta name='venue' content='(.*)'>[\r]?\n~", $file, $matches)) {
  echo "Success";
}
else { 
  echo "Fail";
}

Thanks, but both fail here. Is there some solution using multiline and ^$?? — ChrisJJ, Jan 07 '12 at 04:21
Are you sure? Can you show your file contents and what the place you are trying to match is? — ReadWriteCode, Jan 07 '12 at 04:32

PHP preg match with line ends in Linux and Windows

1 Answers1