理解流方式上传和form表单上传

$post_input = ‘php://input‘;
$save_path = dirname( __FILE__ );
$postdata = file_get_contents( $post_input );

if ( isset( $postdata ) && strlen( $postdata ) > 0 ) {
    $filename = $save_path . ‘/‘ . uniqid() . ‘.jpg‘;
    $handle = fopen( $filename, ‘w+‘ );
    fwrite( $handle, $postdata );
    fclose( $handle );
    if ( is_file( $filename ) ) {
        echo ‘Image data save successed,file:‘ . $filename;
        exit ();
    }else {
        die ( ‘Image upload error!‘ );
    }
}else {
    die ( ‘Image data not detected!‘ );
}

if (!$_FILES[‘Filedata‘]) {
    die ( ‘Image data not detected!‘ );
}
if ($_FILES[‘Filedata‘][‘error‘] > 0) {
    switch ($_FILES [‘Filedata‘] [‘error‘]) {
        case 1 :
            $error_log = ‘The file is bigger than this PHP installation allows‘;
            break;
        case 2 :
            $error_log = ‘The file is bigger than this form allows‘;
            break;
        case 3 :
            $error_log = ‘Only part of the file was uploaded‘;
            break;
        case 4 :
            $error_log = ‘No file was uploaded‘;
            break;
        default :
            break;
    }
    die ( ‘upload error:‘ . $error_log );
} else {
    $img_data = $_FILES[‘Filedata‘][‘tmp_name‘];
    $size = getimagesize($img_data);
    $file_type = $size[‘mime‘];
    if (!in_array($file_type, array(‘image/jpg‘, ‘image/jpeg‘, ‘image/pjpeg‘, ‘image/png‘, ‘image/gif‘))) {
        $error_log = ‘only allow jpg,png,gif‘;
        die ( ‘upload error:‘ . $error_log );
    }
    switch($file_type) {
        case ‘image/jpg‘ :
        case ‘image/jpeg‘ :
        case ‘image/pjpeg‘ :
            $extension = ‘jpg‘;
            break;
        case ‘image/png‘ :
            $extension = ‘png‘;
            break;
        case ‘image/gif‘ :
            $extension = ‘gif‘;
            break;
    }    
}
if (!is_file($img_data)) {
    die ( ‘Image upload error!‘ );
}