php man page for stream_set_chunk_size

STREAM_SET_CHUNK_SIZE(3)						 1						  STREAM_SET_CHUNK_SIZE(3)

stream_set_chunk_size - Set the stream chunk size

SYNOPSIS
       int stream_set_chunk_size (resource  $fp, int  $chunk_size)

DESCRIPTION
	Set the stream chunk size.

PARAMETERS
	      o $fp
		- The target stream.

	      o $chunk_size
		- The desired new chunk size.

RETURN VALUES
	Returns the previous chunk size on success.

	Will return FALSE if $chunk_size is less than 1 or greater than PHP_INT_MAX.

ERRORS
/EXCEPTIONS
	Will emit an E_WARNING level error if $chunk_size is less than 1 or greater than PHP_INT_MAX.

PHP Documentation Group 												  STREAM_SET_CHUNK_SIZE(3)