php script to recognize text from link - php

Question

I was trying to create a script in php, for displaying messages. If the messages includes a web address, then this address I wanted to be displayed as a link. This is my code that works successfuly:
<?php
if( (substr( $message, 0, 8 ) === "https://") || (substr( $message, 0, 7 ) === "http://") ){
echo "<a href='$message' target='_blank'> $message </a>";
}else{
echo " $message ";
}
?>
It is working perfect if the user inserts in message a web address only like: "http://google.com" The problem starts if the users inserts a text before or after the web address. For example if writes: "visit http://google.com site" then it is making all the phrase as a link and it does not recognises the words with the web address. Any idea how to fix this problem?

Answer 1

You may use filter_var with FILTER_VALIDATE_URL:
$words = explode(" ", $message);
$_words = array();
foreach($words as $word){
if(filter_var($word, FILTER_VALIDATE_URL) === false){
$_words[] = $word;
}
else{
$_words[] = "$word";
}
}
echo implode(" ", $_words);
Demo: http://phpfiddle.org/main/code/mu8-vg5

Answer 2

I use this within a class:
public static function CreateLinks($text) {
return preg_replace('#(https?://([-\w.]+[-\w])+(:\d+)?(/([\w-.~:/?#\[\]\#!$&\'()*+,;=%]*)?)?)#', '$1', $text);
}
To use it without a class, do this:
$message = preg_replace('#(https?://([-\w.]+[-\w])+(:\d+)?(/([\w-.~:/?#\[\]\#!$&\'()*+,;=%]*)?)?)#', '$1', $message);
So in a test case this:
$message = "Hello, take a look at http://www.google.com or wait! Maybe you where looking for http://www.bing.com";
$message = preg_replace('#(https?://([-\w.]+[-\w])+(:\d+)?(/([\w-.~:/?#\[\]\#!$&\'()*+,;=%]*)?)?)#', '$1', $message);
echo $message;
Will output:
Hello, take a look at http://www.google.com or wait! Maybe you where looking for http://www.bing.com
So, at the end your code can be replaced by just one single line! Replace this:
if( (substr( $message, 0, 8 ) === "https://") || (substr( $message, 0, 7 ) === "http://") ){
echo "<a href='$message' target='_blank'> $message </a>";
}else{
echo " $message ";
}
by this:
$message = preg_replace('#(https?://([-\w.]+[-\w])+(:\d+)?(/([\w-.~:/?#\[\]\#!$&\'()*+,;=%]*)?)?)#', '$1', $message);

Answer 3

Jan Goyvaerts, Regex Guru, describe pretty well in his blog
http://www.regexguru.com/2008/11/detecting-urls-in-a-block-of-text/
To find all matches in a multi-line string, use
preg_match_all('/\b(?:(?:https?|ftp|file):\/\/|www\.|ftp\.)[-A-Z0-9+&##\/%=~_|$?!:,.]*[A-Z0-9+&##\/%=~_|$]/i', $subject, $result, PREG_PATTERN_ORDER);
$result = $result[0];
you can use preg_match function to get single match