streamWrapper::dir_readdir

(PHP 4 >= 4.3.2, PHP 5)

streamWrapper::dir_readdir — Read entry from directory handle

说明

public string streamWrapper::dir_readdir ( void )

This method is called in response to readdir() .

参数

此函数没有参数。

返回值

Should return string representing the next filename, or FALSE if there is no next file.

Note:

The return value will be casted to string .

错误／异常

调用此方法失败将给出 E_WARNING （未实现）。

范例

Example #1 Listing files from tar archives

  <?php
 class  streamWrapper  {
    protected  $fp ;

    public function  dir_opendir ( $path ,  $options ) {
         $url  =  parse_url ( $path );

         $path  =  $url [ "host" ] .  $url [ "path" ];

        if (! is_readable ( $path )) {
             trigger_error ( " $path  isn't readable for me" ,  E_USER_NOTICE );
            return  false ;
        }
        if (! is_file ( $path )) {
             trigger_error ( " $path  isn't a file" ,  E_USER_NOTICE );
            return  false ;
        }

         $this -> fp  =  fopen ( $path ,  "rb" );
        return  true ;
    }

    public function  dir_readdir () {
         // Extract the header for this entry
         $header       =  fread ( $this -> fp ,  512 );
         $data  =  unpack ( "a100filename/a8mode/a8uid/a8gid/a12size/a12mtime/a8checksum/a1filetype/a100link/a100linkedfile" ,  $header );

         // Trim the filename and filesize
         $filename     =  trim ( $data [ "filename" ]);

         // No filename? We are the end of the archive
         if (! $filename ) {
            return  false ;
        }

         $octal_bytes  =  trim ( $data [ "size" ]);
         // Filesize is defined in octects
         $bytes        =  octdec ( $octal_bytes );

         // tar rounds up filesizes up to multiple of 512 bytes (zero filled)
         $rest         =  $bytes  %  512 ;
        if ( $rest  >  0 ) {
             $bytes       +=  512  -  $rest ;
        }

         // Seek over the file
         fseek ( $this -> fp ,  $bytes ,  SEEK_CUR );

        return  $filename ;
    }

    public function  dir_closedir () {
        return  fclose ( $this -> fp );
    }

    public function  dir_rewinddir () {
        return  fseek ( $this -> fp ,  0 ,  SEEK_SET );
    }
}

 stream_wrapper_register ( "tar" ,  "streamWrapper" );
 $handle  =  opendir ( "tar://example.tar" );
while ( false  !== ( $file  =  readdir ( $handle ))) {
     var_dump ( $file );
}

echo  "Rewinding..\n" ;
 rewind ( $handle );
 var_dump ( readdir ( $handle ));

 closedir ( $handle );
 ?>

以上例程的输出类似于：

string(13) "construct.xml"
string(16) "dir-closedir.xml"
string(15) "dir-opendir.xml"
string(15) "dir-readdir.xml"
string(17) "dir-rewinddir.xml"
string(9) "mkdir.xml"
string(10) "rename.xml"
string(9) "rmdir.xml"
string(15) "stream-cast.xml"
string(16) "stream-close.xml"
string(14) "stream-eof.xml"
string(16) "stream-flush.xml"
string(15) "stream-lock.xml"
string(15) "stream-open.xml"
string(15) "stream-read.xml"
string(15) "stream-seek.xml"
string(21) "stream-set-option.xml"
string(15) "stream-stat.xml"
string(15) "stream-tell.xml"
string(16) "stream-write.xml"
string(10) "unlink.xml"
string(12) "url-stat.xml"
Rewinding..
string(13) "construct.xml"

参见

readdir() - 从目录句柄中读取条目