function tmp( bool, type ) {
	var err;
	var out;
	var f;
	if ( arguments.length > 2 ) {
		out = arguments[ 2 ];
	} else {
		out = TMP;
	}
	if ( bool ) {
		if ( type === 'single-line' ) {
			f = SHEBANG_SINGLE_LINE_HEADER;
		} else {
			f = SHEBANG_MULTI_LINE_HEADER;
		}
		err = writeFileSync( out, readFileSync( f ) );
	} else {
		if ( type === 'single-line' ) {
			f = SINGLE_LINE_HEADER;
		} else {
			f = MULTI_LINE_HEADER;
		}
		err = writeFileSync( out, readFileSync( f ) );
	}
	if ( err ) {
		throw err;
	}
	return out;
}
Creates a temporary file.

@private
@param {boolean} bool - boolean indicating whether a temporary file should include a "shebang"
@param {string} type - header type ('single-line' or 'multi-line')
@param {string} [f] - filename
@throws {Error} unexpected error
@returns {string} temporary file filename