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function is not described

WC_Download_Handler::readfile_chunked() public WC 1.0

Read file chunked.

Reads file in chunks so big downloads are possible without changing PHP.INI - http://codeigniter.com/wiki/Download_helper_for_large_files/.

{} It's a method of the class: WC_Download_Handler{}

No Hooks.

Return

true|false. Success or fail

Usage

$result = WC_Download_Handler::readfile_chunked( $file, $start, $length );
$file(string) (required)
File.
$start(int)
Byte offset/position of the beginning from which to read from the file.
$length(int)
Length of the chunk to be read from the file in bytes, 0 means full file.

Code of WC_Download_Handler::readfile_chunked() WC 5.7.1

public static function readfile_chunked( $file, $start = 0, $length = 0 ) {
	if ( ! defined( 'WC_CHUNK_SIZE' ) ) {
		define( 'WC_CHUNK_SIZE', 1024 * 1024 );
	}
	$handle = @fopen( $file, 'r' ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged, WordPress.WP.AlternativeFunctions.file_system_read_fopen

	if ( false === $handle ) {
		return false;
	}

	if ( ! $length ) {
		$length = @filesize( $file ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
	}

	$read_length = (int) WC_CHUNK_SIZE;

	if ( $length ) {
		$end = $start + $length - 1;

		@fseek( $handle, $start ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
		$p = @ftell( $handle ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged

		while ( ! @feof( $handle ) && $p <= $end ) { // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
			// Don't run past the end of file.
			if ( $p + $read_length > $end ) {
				$read_length = $end - $p + 1;
			}

			echo @fread( $handle, $read_length ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged, WordPress.XSS.EscapeOutput.OutputNotEscaped, WordPress.WP.AlternativeFunctions.file_system_read_fread
			$p = @ftell( $handle ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged

			if ( ob_get_length() ) {
				ob_flush();
				flush();
			}
		}
	} else {
		while ( ! @feof( $handle ) ) { // @codingStandardsIgnoreLine.
			echo @fread( $handle, $read_length ); // @codingStandardsIgnoreLine.
			if ( ob_get_length() ) {
				ob_flush();
				flush();
			}
		}
	}

	return @fclose( $handle ); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged, WordPress.WP.AlternativeFunctions.file_system_read_fclose
}