WordPress中给图片与头像设置alt图片属性

function get_avatar( $id_or_email, $size = '96', $default = '', $alt = false ) { 
    if ( ! get_option('show_avatars') ) 
        return false; 

    if ( false === $alt) 
        $safe_alt = ''; 
        else
        $safe_alt = esc_attr( $alt );

 
function get_avatar( $id_or_email, $size = '96', $default = '', $alt = false ) {     
    if ( ! get_option('show_avatars') )     
        return false;     

    if ( false === $alt)     
        $safe_alt = 'Gravatar';  //Alt属性为“Gravatar”
//      $safe_alt = get_comment_author($alt);  //有说这样写就输出用户名，实测Alt属性为“匿名”
    else   
        $safe_alt = esc_attr($alt);

function photo_alt($c) {
global $post;//全局量
$title = $post->post_title;//文章标题
$s = array('/src="(.+?.(jpg|bmp|png|jepg|gif))"/i' => 'src="$1" alt="'.$title.'"');
foreach($s as $p => $r){
$c = preg_replace($p,$r,$c);
}
return $c;
}
add_filter( 'the_content', 'photo_alt' );