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How do i remove duplicate links from a page except first

I have a problem with some contents, which have the same link again and again, so i want to remove all duplicate links except a single, have anyone idea how to do this????

here is my code which remove all links

function anchor_remover($page) {
    $filter_text = preg_replace("|<<blink>a *<blink>href=\<blink>"(.*)\">(.*)</a>|","\\2",$page); 
    return $filter_text; 
}

add_filter('the_content', 'anchor_remover');

basically i need this for wordpress, to filter the contents and remove duplicate links should have only a single link.

Solution

  • Using preg_replace_callback:

    <?php
/*
 * vim: ts=4 sw=4 fdm=marker noet
 */
$page = file_get_contents('./dupes.html');

function do_strip_link($matches)
{
        static $seen = array();

        if( in_array($matches[1], $seen) )
        {
                return $matches[2];
        }
        else
        {
                $seen[] = $matches[1];
                return $matches[0];
        }
}
function strip_dupe_links($page)
{
        return preg_replace_callback(
                '|<a\s+href="(.*?)">(.*?)</a>|',
                do_strip_link,
                $page
        );
}

$page = strip_dupe_links($page);
echo $page;

    Input:

    <html>
        <head><title>Hi!</title></head>
        <body>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="foo.html">foo</a>
                <a href="bar.html">bar</a>
        </body>
</html>

    Output:

    <html>
        <head><title>Hi!</title></head>
        <body>
                <a href="foo.html">foo</a>
                foo
                foo
                foo
                foo
                foo
                foo
                foo
                foo
                foo
                <a href="bar.html">bar</a>
        </body>
</html>