Here is a function which takes an email address and checks if an gravatar exists or not.
{
// Craft a potential url and test its headers
$hash = md5(strtolower(trim($email)));
$uri = 'http://www.gravatar.com/avatar/' . $hash . '?d=404';
$headers = @get_headers($uri);
if (!preg_match("|200|", $headers[0])) {
$has_valid_avatar = FALSE;
} else {
$has_valid_avatar = TRUE;
}
return $has_valid_avatar;
}
If gravatar exists then it returns true otherwise false.
Here is an another function which checks if gravatar exists or not. This function uses HTTP API and Caching. Its a better method than the above one. This method is more WordPress while the above method is more PHP.
//id or email code borrowed from wp-includes/pluggable.php
$email = '';
if ( is_numeric($id_or_email) ) {
$id = (int) $id_or_email;
$user = get_userdata($id);
if ( $user )
$email = $user->user_email;
} elseif ( is_object($id_or_email) ) {
// No avatar for pingbacks or trackbacks
$allowed_comment_types = apply_filters( 'get_avatar_comment_types', array( 'comment' ) );
if ( ! empty( $id_or_email->comment_type ) && ! in_array( $id_or_email->comment_type, (array) $allowed_comment_types ) )
return false;
if ( !empty($id_or_email->user_id) ) {
$id = (int) $id_or_email->user_id;
$user = get_userdata($id);
if ( $user)
$email = $user->user_email;
} elseif ( !empty($id_or_email->comment_author_email) ) {
$email = $id_or_email->comment_author_email;
}
} else {
$email = $id_or_email;
}
$hashkey = md5(strtolower(trim($email)));
$uri = 'http://www.gravatar.com/avatar/' . $hashkey . '?d=404';
$data = wp_cache_get($hashkey);
if (false === $data) {
$response = wp_remote_head($uri);
if( is_wp_error($response) ) {
$data = 'not200';
} else {
$data = $response['response']['code'];
}
wp_cache_set($hashkey, $data, $group = '', $expire = 60*5);
}
if ($data == '200'){
return true;
} else {
return false;
}
}
Returns true if gravatar exists otherwise false.