Php parse links/emails - php

Question

I am wondering if there is a simple snippet which converts links of any kind:
http://www.cnn.com to http://www.cnn.com
cnn.com to cnn.com
www.cnn.com to www.cnn.com
abc#def.com to to mailto:abc#def.com
I do not want to use any PHP5 specific library.
Thank you for your time.
UPDATE I have updated the above text to what i want to convert it to. Please note that the href tag and the text are different for case 2 and 3.
UPDATE2 Hows does gmail chat do it? Theirs is pretty smart and works only for real domains names. e.g. a.ly works but a.cb does not work.

Answer 1

yes ,
http://www.gidforums.com/t-1816.html
<?php
/**
NAME : autolink()
VERSION : 1.0
AUTHOR : J de Silva
DESCRIPTION : returns VOID; handles converting
URLs into clickable links off a string.
TYPE : functions
======================================*/
function autolink( &$text, $target='_blank', $nofollow=true )
{
// grab anything that looks like a URL...
$urls = _autolink_find_URLS( $text );
if( !empty($urls) ) // i.e. there were some URLS found in the text
{
array_walk( $urls, '_autolink_create_html_tags', array('target'=>$target, 'nofollow'=>$nofollow) );
$text = strtr( $text, $urls );
}
}
function _autolink_find_URLS( $text )
{
// build the patterns
$scheme = '(http:\/\/|https:\/\/)';
$www = 'www\.';
$ip = '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}';
$subdomain = '[-a-z0-9_]+\.';
$name = '[a-z][-a-z0-9]+\.';
$tld = '[a-z]+(\.[a-z]{2,2})?';
$the_rest = '\/?[a-z0-9._\/~#&=;%+?-]+[a-z0-9\/#=?]{1,1}';
$pattern = "$scheme?(?(1)($ip|($subdomain)?$name$tld)|($www$name$tld))$the_rest";
$pattern = '/'.$pattern.'/is';
$c = preg_match_all( $pattern, $text, $m );
unset( $text, $scheme, $www, $ip, $subdomain, $name, $tld, $the_rest, $pattern );
if( $c )
{
return( array_flip($m[0]) );
}
return( array() );
}
function _autolink_create_html_tags( &$value, $key, $other=null )
{
$target = $nofollow = null;
if( is_array($other) )
{
$target = ( $other['target'] ? " target=\"$other[target]\"" : null );
// see: http://www.google.com/googleblog/2005/01/preventing-comment-spam.html
$nofollow = ( $other['nofollow'] ? ' rel="nofollow"' : null );
}
$value = "<a href=\"$key\"$target$nofollow>$key</a>";
}
?>

Answer 2

Try this out. (for links not email)
$newTweet = preg_replace('!http://([a-zA-Z0-9./-]+[a-zA-Z0-9/-])!i', '\\0', $tweet->text);

Answer 3

I know is 5 years late, however I needed a similar solution and the best answer I got was from the user - erwan-dupeux-maire
Answer
I write this function. It replaces all the links in a string. Links can be in the following formats :
www.example.com
http://example.com
https://example.com
example.fr
The second argument is the target for the link ('_blank', '_top'... can be set to false). Hope it helps...
public static function makeLinks($str, $target='_blank')
{
if ($target)
{
$target = ' target="'.$target.'"';
}
else
{
$target = '';
}
// find and replace link
$str = preg_replace('#((https?://)?([-\w]+\.[-\w\.]+)+\w(:\d+)?(/([-\w/_\.]*(\?\S+)?)?)*)#', '<a href="$1" '.$target.'>$1</a>', $str);
// add "http://" if not set
$str = preg_replace('/<a\s[^>]*href\s*=\s*"((?!https?:\/\/)[^"]*)"[^>]*>/i', '<a href="http://$1" '.$target.'>', $str);
return $str;
}

Answer 4

Here's the email snippet:
$email = "abc#def.com";
$pos = strrpos($email, "#");
if (!$pos === false) {
// This is an email address!
$email .= "mailto:" . $email;
}
What exactly are you looking to do with the links? strip the www or http? or add http://www to any link if required?