How do you redirect a PHP page to an IMG?

I have a blog background website. We provide some HTML code that the user can insert into his page, and it has something like this:

<img src="http://example.com/img.jpg" />

Unfortunately, I have had to relocate the images from time to time. Each time I have to relocate the image, the image no longer works for the people who have put the code into their site.

I am wondering if there is a way in PHP so that I can do something like this:

<开发者_运维知识库img src="http://example.com/getImage.php?id=523" />

And have the getImage.php actually redirect to the actual image URL (looked up from my database with the given ID). In this way, I can have one URL to give to the user, and if I ever need to relocate the image, I just do it in my database, and the user's background still works.

Any suggestions?

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Yes. You can use the following to transparently serve a JPEG from php:

header('Content-type: image/jpeg');
readfile('/path/to/file.jpg');
exit;

Alternatively, you can just redirect to the image URL:

header('Location: /web/path/to/file.jpg');
exit;

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header("Location: $url");