The MENU command is used to read, activate, or inactivate command menus.
The 5 different types of menus (PULL-DOWN, FUNCTION, SCREEN, TABLET and
TEMPSCREEN) are all controlled by this command (see MENUS[1] for more
general information on the different types of CIGAL menus).

The FLAG argument controls the meaning of the MENU command:
1-10 Read/Activate menu as Pull-down menu (1-10 is position on menu bar)
11 Read/Activate menu as Function menu
12 Read/Activate menu as Screen menu
13 Read/Activate menu as Tablet menu
14 Read/Activate menu as TempScreen menu
0 Inactivate menu (next argument can specify which menu)
-1 Restore previous menu (next argument can specify which menu)

Note: When reading or activating a Function, Screen, or Tablet menu the
format of the menu is sufficient to indicate which type, so the FLAG
argument is generally not necessary. For a Pull-down menu you only need the
FLAG if you want to specify in which position to put the menu, otherwise it
will appear in the first available menu bar position. For a TempScreen menu
you must specify the flag.

Reading a Menu
If a named menu is not found in CIGAL's system menu library, then the MENU
command will first attempt to read the menu into the library. See
MAKEMENU[1] for information on how to create new command menus.

The DFLG argument can be included to specify menu display options. The
following flags can be combined by addition:
1 SAVMODE save current video display mode with mode; when
the menu is activated in any other video mode it
will automatically switch back to its saved mode
2 SAVSCR store current video screen display as menu display
4 STORTXT store display as processed video text
10o TEMP delete menu from system table when inactivated
(default for '{' if no name specified)
20o STDIN read menu from standard input (default for '{')
Note: the NAME argument is not needed if the menu is temporary, loaded
explicitly, and not a Pull-down menu.

Inactivating a Menu
At any one time you can have 1 Function menu, 1 Screen or Tablet menu,
and up to 10 Pull-down menus active. You inactivate a menu by entering:
menu 0 name
or menu 0 mnu
or menu 0 mnu1 mnu2 mnu3 ...
or menu 0 mnufirst - mnulast
For all but the first of these, the menus to inactivate are specified by
menu position number, as described for the FLAG argument above. If no
menu is specified, the current Screen or Tablet menu is inactivated.
MNUFIRST to MNULAST can be used to inactivate many consecutive menu
numbers.
Examples:
menu 0 ; turn off the screen menu (or tablet)
menu 0 1 - 10 ; inactivate all pull-down menus

Reactivating menus
Pull-down or function menus that have been inactivated, can be
reactivated by entering the command:
menu - mnu1 mnu2 ...
or menu - mnufirst - mnulast
Examples:
menu - 11 ; reactivate the function key menu
menu - 1 - 10 ; reactivate all pull-down menus

Restoring Previous Menu

Redrawing the Menu Display
If at any time the menu display disappears, you can redraw it with:
menu

For more information see:
MENUS[1] for an overview of CIGAL menus
MAKEMENU[1] to define a new menu
SHOW[2] to find out which menus are loaded
DELETE[2] to delete a menu from the system menu library
DIR[2] to get a list of menu files
EDIT[2] to create or modify a menu file
WINDOWS[1] for how the display screen is controlled
TABLETS[1] for using a digitizing tablet