wordpress中的函数

 /**
  * 检查是否是一个序列化数据.
  *
  * If $data is not an string, then returned value will always be false.
  * Serialized data is always a string.
  *
  * @since 2.0.5
  *
  * @param mixed $data Value to check to see if was serialized.
  * @return bool False if not serialized and true if it was.
  */  
 function is_serialized( $data ) {  
     // if it isn't a string, it isn't serialized  
     if ( !is_string( $data ) )  
         return false;  
     $data = trim( $data );  
     if ( 'N;' == $data )  
         return true;  
     if ( !preg_match( '/^([adObis]):/', $data, $badions ) )  
         return false;  
     switch ( $badions[1] ) {  
         case 'a' :  
         case 'O' :  
         case 's' :  
             if ( preg_match( "/^{$badions[1]}:[0-9]+:.*[;}]\$/s", $data ) )  
                 return true;  
             break;  
         case 'b' :  
         case 'i' :  
         case 'd' :  
             if ( preg_match( "/^{$badions[1]}:[0-9.E-]+;\$/", $data ) )  
                 return true;  
             break;  
     }  
     return false;  
 }  
   
 /**
  * 检查是否是一个字符串序列化数据
  *
  * @since 2.0.5
  *
  * @param mixed $data Serialized data
  * @return bool False if not a serialized string, true if it is.
  */  
 function is_serialized_string( $data ) {  
     // if it isn't a string, it isn't a serialized string  
     if ( !is_string( $data ) )  
         return false;  
     $data = trim( $data );  
     if ( preg_match( '/^s:[0-9]+:.*;$/s', $data ) ) // this should fetch all serialized strings  
         return true;  
     return false;  
 }  
   
 /**
  * http状态转换成说明
  *
  * @since 2.3.0
  *
  * @param int $code HTTP status code.
  * @return string Empty string if not found, or description if found.
  */  
 function get_status_header_desc( $code ) {  
     global $wp_header_to_desc;  
   
     $code = absint( $code );  
   
     if ( !isset( $wp_header_to_desc ) ) {  
         $wp_header_to_desc = array(  
             100 => 'Continue',  
             101 => 'Switching Protocols',  
   
             200 => 'OK',  
             201 => 'Created',  
             202 => 'Accepted',  
             203 => 'Non-Authoritative Information',  
             204 => 'No Content',  
             205 => 'Reset Content',  
             206 => 'Partial Content',  
   
             300 => 'Multiple Choices',  
             301 => 'Moved Permanently',  
             302 => 'Found',  
             303 => 'See Other',  
             304 => 'Not Modified',  
             305 => 'Use Proxy',  
             307 => 'Temporary Redirect',  
   
             400 => 'Bad Request',  
             401 => 'Unauthorized',  
             403 => 'Forbidden',  
             404 => 'Not Found',  
             405 => 'Method Not Allowed',  
             406 => 'Not Acceptable',  
             407 => 'Proxy Authentication Required',  
             408 => 'Request Timeout',  
             409 => 'Conflict',  
             410 => 'Gone',  
             411 => 'Length Required',  
             412 => 'Precondition Failed',  
             413 => 'Request Entity Too Large',  
             414 => 'Request-URI Too Long',  
             415 => 'Unsupported Media Type',  
             416 => 'Requested Range Not Satisfiable',  
             417 => 'Expectation Failed',  
   
             500 => 'Internal Server Error',  
             501 => 'Not Implemented',  
             502 => 'Bad Gateway',  
             503 => 'Service Unavailable',  
             504 => 'Gateway Timeout',  
             505 => 'HTTP Version Not Supported'  
         );  
     }  
   
     if ( isset( $wp_header_to_desc[$code] ) )  
         return $wp_header_to_desc[$code];  
     else  
         return '';  
 }  
   
 /**
  * 发送一个让页面不缓存的http头信息
  *
  * Different browsers support different nocache headers, so several headers must
  * be sent so that all of them get the point that no caching should occur.
  *
  * @since 2.0.0
  */  
 function nocache_headers() {  
     // why are these @-silenced when other header calls aren't?  
     @header( 'Expires: Wed, 11 Jan 1984 05:00:00 GMT' );  
     @header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' );  
     @header( 'Cache-Control: no-cache, must-revalidate, max-age=0' );  
     @header( 'Pragma: no-cache' );  
 }  
   
 /**
  * 让javascript缓存10天的http头信息
  *
  * @since 2.1.0
  */  
 function cache_javascript_headers() {  
     $expiresOffset = 864000; // 10 days  
     header( "Content-Type: text/javascript; charset=" . get_bloginfo( 'charset' ) );  
     header( "Vary: Accept-Encoding" ); // Handle proxies  
     header( "Expires: " . gmdate( "D, d M Y H:i:s", time() + $expiresOffset ) . " GMT" );  
 }  
   
 /**
  * 递归创建一个完整的目录(整个目录中的子目录不存在都创建)
  *
  * Will attempt to set permissions on folders.
  *
  * @since 2.0.1
  *
  * @param string $target Full path to attempt to create.
  * @return bool Whether the path was created or not. True if path already exists.
  */  
 function wp_mkdir_p( $target ) {  
     // from php.net/mkdir user contributed notes  
     $target = str_replace( '//', '/', $target );  
     if ( file_exists( $target ) )  
         return @is_dir( $target );  
   
     // Attempting to create the directory may clutter up our display.  
     if ( @mkdir( $target ) ) {  
         $stat = @stat( dirname( $target ) );  
         $dir_perms = $stat['mode'] & 0007777;  // Get the permission bits.  
         @chmod( $target, $dir_perms );  
         return true;  
     } elseif ( is_dir( dirname( $target ) ) ) {  
             return false;  
     }  
   
     // If the above failed, attempt to create the parent node, then try again.  
     if ( ( $target != '/' ) && ( wp_mkdir_p( dirname( $target ) ) ) )  
         return wp_mkdir_p( $target );  
   
     return false;  
 }  
   
 /**
  * 检查是否是个绝对路径 ('/foo/bar', 'c:\windows').
  *
  * @since 2.5.0
  *
  * @param string $path File path
  * @return bool True if path is absolute, false is not absolute.
  */  
 function path_is_absolute( $path ) {  
     // this is definitive if true but fails if $path does not exist or contains a symbolic link  
     if ( realpath($path) == $path )  
         return true;  
   
     if ( strlen($path) == 0 || $path{0} == '.' )  
         return false;  
   
     // windows allows absolute paths like this  
     if ( preg_match('#^[a-zA-Z]:\\\\#', $path) )  
         return true;  
   
     // a path starting with / or \ is absolute; anything else is relative  
     return (bool) preg_match('#^[/\\\\]#', $path);  
 }  
   
 /**
  * 根据扩展名获得文件类型
  *
  * @package WordPress
  * @since 2.5.0
  * @uses apply_filters() Calls 'ext2type' hook on default supported types.
  *
  * @param string $ext The extension to search.
  * @return string|null The file type, example: audio, video, document, spreadsheet, etc. Null if not found.
  */  
 function wp_ext2type( $ext ) {  
     $ext2type = apply_filters('ext2type', array(  
         'audio' => array('aac','ac3','aif','aiff','mp1','mp2','mp3','m3a','m4a','m4b','ogg','ram','wav','wma'),  
         'video' => array('asf','avi','divx','dv','mov','mpg','mpeg','mp4','mpv','ogm','qt','rm','vob','wmv'),  
         'document' => array('doc','docx','pages','odt','rtf','pdf'),  
         'spreadsheet' => array('xls','xlsx','numbers','ods'),  
         'interactive' => array('ppt','pptx','key','odp','swf'),  
         'text' => array('txt'),  
         'archive' => array('tar','bz2','gz','cab','dmg','rar','sea','sit','sqx','zip'),  
         'code' => array('css','html','php','js'),  
     ));  
     foreach ( $ext2type as $type => $exts )  
         if ( in_array($ext, $exts) )  
             return $type;  
 }  
   
 /**
  * 转换成正整数
  *
  * @since 2.5.0
  *
  * @param mixed $maybeint Data you wish to have convered to an absolute integer
  * @return int An absolute integer
  */  
 function absint( $maybeint ) {  
     return abs( intval( $maybeint ) );  
 }