Question

Trying to display an image only for Android users, but I don’t want to use any redirection for it.

So far I have this, but it uses header() which redirects.

if (strstr($_SERVER['HTTP_USER_AGENT'],"Android")) {
        header("Location: app.png");
}

Answer 1

You can just output the image in your page, using readfile. Make sure to send the correct headers as well.

For example:

if(strstr($_SERVER['HTTP_USER_AGENT',"Android")) 
{
 header('content-type: application/png'); //Let the client know its a png.
 readfile('app.png');
}

This way any request made to your page using Android will result in the raw image being returned. If you want to ‘force’ the client to download the image send the content-disposition header as well.