PHP 随机显示某张图片

随机显示指定图像文件夹下的所有图片

<?
# Init Array
$files = array();
# Get Folder
if($_GET[&#39;folder&#39;]) {
    $folder = $_GET[&#39;folder&#39;];
} else {
    # Set Default Folder
    $folder = &#39;/img/&#39;;
}
# Set Full Path
$path = $_SERVER[&#39;DOCUMENT_ROOT&#39;] . &#39;/&#39; . $folder;
# Open Directory
if($handle = opendir($path)) {
    # Loop Through Directory
    while(false !== ($file = readdir($handle))) {
        if ($file != "." && $file != "..") { 
            if(substr($file, -3) == &#39;gif&#39; || substr($file, -3) == &#39;png&#39; || substr($file, -3) == &#39;jpg&#39; || substr($file, -4) == &#39;jpeg&#39;) $files[count($files)] = $file;
                }
    }
}
# Close Handle
closedir($handle); 
# Init Random
$rand = rand(0, count($files)-1);
# Check Header Type
# GIF
if(substr($files[$random], -3) == &#39;gif&#39;) header("Content-type: image/gif");
# JPEG
elseif(substr($files[$random], -3) == &#39;jpg&#39;) header("Content-type: image/jpeg");
elseif(substr($files[$random], -4) == &#39;jpeg&#39;) header("Content-type: image/jpeg");
# PNG
elseif(substr($files[$random],-3) == &#39;png&#39;) header("Content-type: image/png");
# Read File
readfile($path . &#39;/&#39; . $files[$random]);
?>