(no version information, might be only in CVS)
php_stream_copy_to_stream -- Copy data from one stream to another
Description
size_t 
php_stream_copy_to_stream ( php_stream * src, php_stream * dest, size_t maxlen)
     php_stream_copy_to_stream() attempts to read up to maxlen
      bytes of data from src and write them to dest,
      and returns the number of bytes that were successfully copied.
    
     If you want to copy all remaining data from the src stream, pass the
     constant PHP_STREAM_COPY_ALL as the value of maxlen.
    
注: 
      This function will attempt to copy the data in the most efficient manner, using memory mapped
      files when possible.