email address recognition

[edotdeeney]

I have a text block stored in a database and when I pull it out I want all email addresses that it contains to be surrounded by the <a href="mailto:...>address</a> code. Sometimes there are none and sometimes there are more than one. I already have the code automatically changing web addresses to links (using preg_replace) but can't seem to get it working for email addresses. Any help greatly appreciated

Many thanks in advance

[NogDog]

function email_to_link($text)
{
   $qtext = '[^\\x0d\\x22\\x5c\\x80-\\xff]';
   $dtext = '[^\\x0d\\x5b-\\x5d\\x80-\\xff]';
   $atom = '[^\\x00-\\x20\\x22\\x28\\x29\\x2c\\x2e\\x3a-\\x3c' .
      '\\x3e\\x40\\x5b-\\x5d\\x7f-\\xff]+';
   $quoted_pair = '\\x5c[\\x00-\\x7f]';
   $domain_literal = "\\x5b($dtext|$quoted_pair)*\\x5d";
   $quoted_string = "\\x22($qtext|$quoted_pair)*\\x22";
   $domain_ref = $atom;
   $sub_domain = "($domain_ref|$domain_literal)";
   $word = "($atom|$quoted_string)";
   $domain = "$sub_domain(\\x2e$sub_domain)*";
   $local_part = "$word(\\x2e$word)*";
   $addr_spec = "$local_part\\x40$domain";
   return preg_replace("!\b$addr_spec\b!e", "'<a href=\"mailto:'." .
      "htmlspecialchars('$0', ENT_QUOTES).'\">'.htmlspecialchars('$0', ENT_QUOTES).'</a>'",
      $text);
}

[edotdeeney]

I won't begin to pretend I can see what's going on here but thank you: it works beautifully.

[NogDog]

Here's the article where I got the code to build the regular expression, if you want to try to understand it: http://www.iamcal.com/publish/articles/php/parsing_email/