php - str_replace() not working as expected -

i'm trying replace src attribute of images in string $content using str_replace.

the src of these images links ../img/article/foo.jpg want each iteration set img/article/foo.jpg instead.

my code this:

$content = str_replace('../img/article', 'img/article', $content); 

this doesn't return changes $content.

what doing wrong?

edit

here full function sanitize user's input:

function remove_styles($text) {     $content = trim($content);     $content = preg_replace('#(<[a-z ]*)(style=("|\')(.*?)("|\'))([a-z ]*>)#', '\\1\\6', $text);     $content = preg_replace('/(<[^>]+) style=".*?"/i', '$1', $content);     $content = strip_tags($content,'<h2><h3><p><strong><a><ul><li><img>');     $content = str_replace('../img/article','img/article',$content);     return $content; } 

this removes styles, trims whitespace, strips tags , corrects relative path.

the content tinymce editor, , sample looks this:

<p data-wr_replaced="true">your job search has gone well. you've aced interviews, you've worked through technical tests, you've wowed partners , you've got offer looking @ firm you've wanted work at.</p> <p data-wr_replaced="true">but when want resign, current workplace offers you more. more money, more holiday, more opportunity.</p> <p data-wr_replaced="true">now i'm not going should or shouldn't - there plenty of other guides giving clear advice out there:</p> <p> <img src="../img/article/6a3184a558a98656e900f4aa106c387c.png" alt="" width="479" height="662" /></p> 

the image uploaded via wysiwyg editor , saves relative path, incorrect on page article ends being displayed.

you can use capture grouping preg_replace function :

$content = preg_replace('/[\w/]+/(\w+/\w+)/i', '$1', $content); 

demo