Search and replace all image files in HTML document

[Charles Bronte]

Hey there;

I'm working on creating a Wordpress plugin, but it turns out that my Regular Expressions-fu is lacking.

How can you replace all image files (jpg, gif, jpeg)?

I'm thinking a function with the following

- Receive HTML in a string

- Only replace image urls starting with http://example.com

- Replace the domain with http://example2.com

- Return HTML with image URLs replaced.


... But I can't for the life of me create a well-formed piece of code that does this for me.

Any ideas?

[kovik]

Well, I'm assuming by "image files", you mean <img> tags. Basically, you want to search for those tags and make your replacement. Since you've shown that the example that you want to replace is http://example.com to http://example2.com, I can give you a nice little snippet to get you started.

function replace_images($text) {
  /** Regex Parts:
   * \1 is the img tag up to the starting quotation mark
   *    around the file name
   * \2 is the quotation mark
   * \3 is the file name without the domain name
   * \4 is the img tag after the ending quotation mark
   *    around the file name
   */
  $current_domain = 'http://example.com/';
  $target_domain= 'http://example2.com/';
  $img_tag_regex = "(<img[^>]+src=)([\"'])$current_domain([^\2]+?)\2([^>]*>)";
  return preg_replace("~$img_tag_regex~s", "\\1\\2$target_domain\\3\\2\\4", $text);
}

Untested, btw. Since you are doing this in WordPress, you'll probably want to set thus function up as a filter.