function tmp( bool ) {
	var err;
	var f;
	if ( arguments.length > 1 ) {
		f = arguments[ 1 ];
	} else {
		f = TMP;
	}
	if ( bool ) {
		err = writeFileSync( f, readFileSync( FILE_SHEBANG ) );
	} else {
		err = writeFileSync( f, readFileSync( FILE ) );
	}
	if ( err ) {
		throw err;
	}
	return f;
}
Creates a temporary file.

@private
@param {boolean} bool - boolean indicating whether a temporary file should include a "shebang"
@param {string} [f] - filename
@throws {Error} unexpected error
@returns {string} temporary file filename