var icFile = exports.icFile = function (filename, onDone, to_cache) {
    
	// file description
	// NOTE: declare here will make it unaccessible by using 'this' if called within a callback
	
	// file descriptor (as public variable)
	this.fd = undefined;

	// text content as a string
	this.data = '';
	
	// array to store current text content
	this.textArray = [];

	// most recently written line
	this.textLine = '';
	
	that = this;
	
	if (filename) {
		this.open(filename, onDone, to_cache);
	}
}