404错误页面〜重定向图像-PHP

Question

I use a custom 404 page in a PHP application.

On that 404 page, I check for certain 'known' older pages that no longer exist, and then redirect user to newer or most relevant current page. Works great.

Now I am faced with a series of old images that have been removed, and am looking for a way to redirect the images to a new image (all inside of the php code if possible).

I have hunted around briefly and came up empty.

Any way to do this?

Here is a sample of my code:

<?php
    //-- grab info regarding bad request --
    $root       = $_SERVER['DOCUMENT_ROOT'];
    $page       = parse_url($_SERVER['REQUEST_URI']);
    $page       = $page['path'];
    $referer        = $_SERVER['HTTP_REFERER'];
    $host       = $_SERVER['REMOTE_HOST'];

    //-- try to redirect old pages/files ----------------------
    //
    $page = urlencode($page);

    if ( stristr($page, "some_old_file.zip") ) {
        // Example file redirect
        echo    "<META HTTP-EQUIV=\"refresh\" CONTENT=\"0;URL=http://www.site.com/the/new/file.zip\">";

    } elseif ( stristr($page, "some_old_page.php") ) {  
        // example webpage redirect
        echo    "<META HTTP-EQUIV=\"refresh\" CONTENT=\"0;URL=http://www.site.com/the/new/page.php\">";

    } elseif ( stristr($page, "some_old_image.jpg") ) {
        // not sure how to do this ...
        // ...
        // ...
        // ...
        // ...
        // ...
        // not sure how to do this ...          
    } else {
        // everything else - direct to custom 404 search page
        echo    "<META HTTP-EQUIV=\"refresh\" CONTENT=\"0;URL=http://www.site/com/the/custom/404_help.php?page={$page}\">";
    }
    //
    // -------------------------------------------------------

?>

Answer 1

instead of outputting a meta refresh, use a location header

header("Location: /path/to/image.jpg\r\n");

The \\r\\n is just a new line to delimit the headers.

Note: headers must be sent before any other output

Answer 2

You will need server side redirect. Look around php function "header" and http status code 301 (moved permanently). You'll find a ton of ready made 5 liner solutions.

If I were you, I'd use this method for html content too to inform the search engines about the new location of the same content.

Answer 3

My recommendation would be to do this inside Apache using Apache redirects (in your Apache conf files or .htaccess). You can do something like this:

RedirectMatch old_file_path new_file_path

This will not only improve your performance but you won't have to do a lookup each time. And the best part is that it will be manageable should you need to add more missing redirects in the future.