CIGAL Reference Manual, Chapter 4 (Variables): quitstr
usage: quitstr = string
QUITSTR is an internally defined character string variable. This string is executed as a CIGAL command(s) (see EXEC(2)) when the QUIT command is executed, before terminating the CIGAL program. QUITSTR can therefore be used for example to reset various system parameters to their standard values before leaving CIGAL.