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do_action( "hook_name" )apply_filters( "hook_name", "what_to_filter" ).Remember, this hook may occur in more than one file. Moreover, the hook's context may change from version to version.
This hook occurs 10 times in this file.
| Line | Code |
|---|---|
| 1363 | * @since 0.71 |
| 1364 | * |
| 1365 | * @param string $email Email address to verify. |
| 1366 | * @param boolean $check_dns Whether to check the DNS for the domain using checkdnsrr(). |
| 1367 | * @return string|bool Either false or the valid email address. |
| 1368 | */ |
| 1369 | function is_email( $email, $check_dns = false ) { |
| 1370 | // Test for the minimum length the email can be |
| 1371 | if ( strlen( $email ) < 3 ) { |
| 1372 | return apply_filters( 'is_email', false, $email, 'email_too_short' ); |
| 1373 | } |
| 1374 | |
| 1375 | // Test for an @ character after the first position |
| 1376 | if ( strpos( $email, '@', 1 ) === false ) { |
| 1377 | return apply_filters( 'is_email', false, $email, 'email_no_at' ); |
| 1378 | } |
| 1379 | |
| 1380 | // Split out the local and domain parts |
| 1381 | list( $local, $domain ) = explode( '@', $email, 2 ); |
| 1382 | |
| 1383 | // LOCAL PART |
| 1384 | // Test for invalid characters |
| 1385 | if ( !preg_match( '/^[a-zA-Z0-9!#$%&\'*+\/=?^_`{|}~\.-]+$/', $local ) ) { |
| 1386 | return apply_filters( 'is_email', false, $email, 'local_invalid_chars' ); |
| 1387 | } |
| 1388 | |
| 1389 | // DOMAIN PART |
| 1390 | // Test for sequences of periods |
| 1391 | if ( preg_match( '/\.{2,}/', $domain ) ) { |
| 1392 | return apply_filters( 'is_email', false, $email, 'domain_period_sequence' ); |
| 1393 | } |
| 1394 | |
| 1395 | // Test for leading and trailing periods and whitespace |
| 1396 | if ( trim( $domain, " \t\n\r\0\x0B." ) !== $domain ) { |
| 1397 | return apply_filters( 'is_email', false, $email, 'domain_period_limits' ); |
| 1398 | } |
| 1399 | |
| 1400 | // Split the domain into subs |
| 1401 | $subs = explode( '.', $domain ); |
| 1402 | |
| 1403 | // Assume the domain will have at least two subs |
| 1404 | if ( 2 > count( $subs ) ) { |
| 1405 | return apply_filters( 'is_email', false, $email, 'domain_no_periods' ); |
| 1406 | } |
| 1407 | |
| 1408 | // Loop through each sub |
| 1409 | foreach ( $subs as $sub ) { |
| 1410 | // Test for leading and trailing hyphens and whitespace |
| 1411 | if ( trim( $sub, " \t\n\r\0\x0B-" ) !== $sub ) { |
| 1412 | return apply_filters( 'is_email', false, $email, 'sub_hyphen_limits' ); |
| 1413 | } |
| 1414 | |
| 1415 | // Test for invalid characters |
| 1416 | if ( !preg_match('/^[a-z0-9-]+$/i', $sub ) ) { |
| 1417 | return apply_filters( 'is_email', false, $email, 'sub_invalid_chars' ); |
| 1418 | } |
| 1419 | } |
| 1420 | |
| 1421 | // DNS |
| 1422 | // Check the domain has a valid MX and A resource record |
| 1423 | if ( $check_dns && function_exists( 'checkdnsrr' ) && !( checkdnsrr( $domain . '.', 'MX' ) || checkdnsrr( $domain . '.', 'A' ) ) ) { |
| 1424 | return apply_filters( 'is_email', false, $email, 'dns_no_rr' ); |
| 1425 | } |
| 1426 | |
| 1427 | // Congratulations your email made it! |
| 1428 | return apply_filters( 'is_email', $email, $email, null ); |
| 1429 | } |
| 1430 | |
| 1431 | /** |
| 1432 | * Convert to ASCII from email subjects. |
| 1433 | * |
| 1434 | * @since 1.2.0 |
| 1435 | * @usedby wp_mail() handles charsets in email subjects |
| 1436 | * |
| 1437 | * @param string $string Subject line |