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MENUC(1)                  BSD General Commands Manual                 MENUC(1)

     menuc -- menu compiler

     menuc [-o name] file

     This implements a curses based menu system.  A source file that describes
     menus, their options, and how to process the options is given to menuc
     and produces both a .c and a .h file that implement the menu system.  The
     standard base name of the files is menu_defs.  The -o name can be used to
     specify a different base name.

     MENUDEF  Can be set to point to a different set of definition files for
              menuc.  The current location defaults to /usr/share/misc.

     The input file defines static menus and options for processing those
     menus.  It also contains comments, initial C code that is required to
     provide for definitions and other code necessary for the menu system, and
     an option declaration if dynamic menus are requested.

     Comments may appear anywhere in the input file and are like a space in
     the input.  They are like C comments starting with /* and ending with */.
     They are unlike C comments in that they may be nested.  A comment does
     not end until a matching end comment is found.

     In many places, C code is included in the definition file.  All C code is
     passed verbatim to the C output file.  menuc comments do not start in C
     code and comments in the C code are passed verbatim to the output.  The C
     comments are not recognized by menuc.  In all cases, C code starts with a
     left brace ({) and ends with the matching right brace (}).  It is
     important to recognize that in code segments, any brace will be counted,
     even if it is in a C comment inside the code.

     The file contains an initial (and optional) code block followed by any
     number of menu definition elements in any order.  The initial code block
     usually contains includes of header files used by code in the menu code
     blocks later in the file.  If USER_MENU_INIT is #defined, then it will be
     evaluated before the rest of the menu is initialised, if it evaluates to
     a non-zero value then the initialisation will fail.  The file is free
     format, so the actual formatting of the input file is to the taste of the

     All other C code that will appear in an action.  This will be specified
     as <action> in later text.  Such an action will appear as:
           action <opt_endwin> <code>
     in the file.  The <opt_endwin>, if present is:
     and specifies that the curses endwin() function should be called before
     executing the code and then reinstating the current curses window after
     the code has been run.  The <code> is as described above.

     There are four kinds of menu definition elements.  The first one just
     declares whether the programmer wants dynamic menus available.  The
     default is static menus only.  The static menus are the ones defined by
     the menu definitions and do not change at run time.  The dynamic menus
     provide the programmer with a method to create and modify menus during
     the running of the program.  To include dynamic menus, one needs only add
     the declaration:
           allow dynamic menus;
     The semicolon is required to terminate this declaration.  This
     declaration may appear anywhere in the file, but usually appears before
     any menus are defined.

     The next element is a code block to execute if the curses screen can not
     be successfully initialized.  The declaration
           error code;
     tells the menu system to execute the associated code block if the
     initialization fails.  If no code is provided, a default code block is
     used that prints
           Could not initialize curses.
     and exits.  This element may appear anywhere in the file but usually
     appears before any menus are defined.

     The next element defines default options for menus.  Each menu is built
     from a list of options.  These options include the location of the upper
     left corner of the menu, whether there is a "box" drawn around the menu,
     whether the menu is scrollable, the menu's title, whether shortcut
     letters are allowed, whether a standard exit option should be included in
     the menu and text associated with the standard exit option.  The general
     format is:
           default <comma separated option list>;

     The supported options are:

     x = startx       The column number of the upper left corner of the menu
                      window.  If startx is -1 the menu will be centered

     y = starty       The row number of the upper left corner of the menu
                      window.  If starty is negative then the menu will be
                      placed below any message text, but in at least row

     h = height       Specifies the number of menu entries to be displayed.
                      If zero, the height will be based on the number of

     h = width        Specifies the width of the menu window.  If zero, the
                      width will be that of the longest menu text line.

     title text       The specified text will be displayed at the top of the
                      menu window (inside any box).

     box              If specified, draw a box around the menu.

     clear            If specified, clear the window before performing the

     exit             If specified add an addition option to exit the menu.

     exitstring text  The menu label for the exit option.  If not specified
                      defaults to "exit".

     default exit     If specified, place the cursor on the exit line of the
                      menu, instead of the top line.

     shortcut         If specified, add alphabetic tags to each menu line.

     scrollable       If specified, and the menu has more lines than will fit
                      in its window, then only part of the menu will be
                      displayed and the '<' and '>' keys will scroll the
                      displayed menu lines.

     always scroll    If specified, allow for the scroll message line even if
                      the menu doesn't appear to have too many lines.  Useful
                      for dynamic menus, when the number of entries isn't
                      known when the menu window is created..

     sub menu         If specified, the screen contents that the menu window
                      overwrites are saved and restored when the menu exits.
     The box, clear, exit, default exit, shortcut, scrollable, always scroll,
     and sub menu options can be preceded by no in order to negate a default.

     The text arguments can be either a quoted text string or a name #defined
     to something suitable for initialising a const char * field.

     The default declaration may appear multiple times.  Each time, it sets
     the default values for menu definitions that follow in the file.  In each
     menu definition, any or all of these default definitions may be
     overridden for that menu.

     The final element is the actual static menu definitions.  The format and
     order for a menu definition is:

           menu <name> <options> ;
             <display action>
             <menu items>
             <exit action>
             <help text>

     Names are unquoted strings of alpha-numeric and underscore characters.
     They must start with an alpha character.  In C source, a menu named "foo"
     is appears as "MENU_foo".  (Capitalization is important.)  This is
     important, because the menu is displayed and processed by calling the
           process_menu (MENU_foo, arg);

     The options are a comma separated list of options as in the "default"
     declaration.  These override the options from the most recent default

     The display action is optional and provides C code to execute at each and
     every time the menu is displayed for processing.  If it is included, the
     format is:
           display <action>;

     The bulk of the menu definition is the specification of the menu items.
     The general format of a menu item is:
           option <string>, <element_list>;
     The <string> is the text displayed for the menu item, this must be a
     quoted string or a name #defined to something that will initialise a
     const char * field.  There may be an arbitrary number of these items.
     (If there are shortcuts in the menu, a practical limit of 51 should be
     recognized.  It produces shortcuts a to w, y, z, and A to Z.  x is the
     shortcut for the exit item.)

     The <element_list> is a comma separated list of what to do when the item
     is selected.  They may appear in any order.

     The first element processed when a menu item is selected is the
     associated action.  The next element to be processed is the sub or next
     menu option.  They are declared as:
           next menu <name>
           sub menu <name>
     The difference between these two is that a sub menu will return to the
     current menu when exited.  The next menu will just replace the current
     menu and when exited, will return to where the current menu would have
     gone.  Only one of menu element may be used for each menu item.  Finally,
     after processing both the action and a sub menu, the current menu will be
     exited if the element
     is specified.  Note: If exit is specified, next menu will not work
     because the menu system will exit the current menu, even if current has
     been set by next menu.

     After all menu items, the final two menu definition elements may appear.
     The exit action is optional and provides C code to execute in the process
     of exiting a menu.  If it is included, the format is:
           exit <action>;

     The final part of the menu definition is the optional help string.  The
     format is:
           help <text>;
     This text is displayed in a full page help window if the question mark is
     typed.  The actual help text starts with a left brace ({) and ends with
     the matching right brace (}).  The braces are not included in the help
     string, but all other characters between them are included.  Newlines in
     the code translate to newlines in the help text.  Alternatively, the name
     of a const char * variable may be given.

     If requested, menuc supports dynamic menus by allowing the user to create
     new menus.  The related definitions for using dynamic menus are:

     struct menudesc;

     struct menu_ent {
             const char  *opt_name;
             int         opt_menu;
             int         opt_flags;
             int         (*opt_action)(struct menudesc *, void *);
     } menu_ent ;

     /* For opt_menu */
     #define OPT_NOMENU -1

     /* For opt_flags */
     #define OPT_SUB    1
     #define OPT_ENDWIN 2
     #define OPT_EXIT   4

     struct menudesc {
             const char  *title;
             int         y, x;
             int         h, w;
             int         mopt;
             int         numopts;
             int         cursel;
             int         topline;
             menu_ent    *opts;
             WINDOW      *mw;
             WINDOW      *sv_mw;
             const char  *helpstr;
             const char  *exitstr;
             void       (*post_act)(struct menudesc *, void *);
             void       (*exit_act)(struct menudesc *, void *);
             void       (*draw_line)(struct menudesc *, int, void *);
     } menudesc ;

     /* defines for mopt field. */
     #define MC_NOEXITOPT 1
     #define MC_NOBOX 2
     #define MC_SCROLL 4
     #define MC_NOSHORTCUT 8
     #define MC_NOCLEAR 16
     #define MC_DFLTEXIT 32
     #define MC_ALWAYS_SCROLL 64
     #define MC_SUBMENU 128

     int new_menu(const char *title, menu_ent *opts, int numopts,
             int x, int y, int h, int w, int mopt,
             void (*post_act)(struct menudesc *, void *),
             void (*draw_line)(struct menudesc *, int, void *),
             void (*exit_act)(struct menudesc *, void *),
             const char *help, const char *exitstr);

     void free_menu (int menu_no);

     The title is the title displayed at the top of the menu.  The opts is an
     array of menu entry definitions that has numopts elements.  The
     programmer must build this array and fill in all of the fields before
     processing calling process_menu() for the new menu.  The fields of the
     opts may change at any time.  For example, opt_name may change as a
     result of selecting that option.  When the menu is redisplayed, the new
     text is printed.  Arguments, x, y, h, and w are the same as the options
     in the menu description.  mopt is the boolean options.  Note, box, clear,
     exit and shortcuts are enabled by default.  You need to add option flags
     to turn them off or turn on scrollable menus.  The options post_act, and
     exit_act are function pointers to the display action and the exit action.
     If they are NULL, no call will be made.  draw_line will be called to
     display the menu line if the corresponding opt_name field is NULL.  help
     is the text to display in a help screen.  And finally, exitstr is the
     text for the 'exit' line of the menu.  If NULL, "Exit" is used.  A NULL
     help pointer will disable the help feature for the menu.


     The following is a simple menu definition file.  It is complete in that
     the output of menuc may be compiled into a complete program.  For
     example, if the following was in a file called, an executable
     program could be produced by the following commands.

           menuc -o example
           cc -o example example.c -lcurses
     A much more complete example is available with the source distribution in
     a subdirectory called testm.

     /* This is an example menu definition file for menuc. */

     #include <stdio.h>
     #include <unistd.h>

     /* Main program! This is often in a different file. */
         process_menu (MENU_main, NULL);
         return 0;

     /* Example initialize function! */

     default x=20, y=10, box, scrollable, exit;

     error action {
        fprintf (stderr, "Example Menu: Could not initialize curses.");

     menu main, title "Main Menu", no exit, no shortcut;
        display action { init_main(); };
        option "Option 1",
           action (endwin) {
             printf ("That was option 1!");
        option "Sub Menu", sub menu othermenu;
        option "Next Menu", next menu othermenu;
        option "Quit", exit;
        help {
     This is a simple help screen for an example menu definition file.

     menu othermenu, title "Sub/Next Menu", x=5, y=5, no box;
        option "Do Nothing!", action { };


     Philip A. Nelson for Piermont Information Systems Inc.  Initial ideas for
     this were developed and implemented in Pascal at the Leiden University,
     Netherlands, in the summer of 1980.

     Both menuc and msgc are probably only used by sysinst.  The features of
     both have been tailored for sysinst, and further changes are likely to

BSD                             August 2, 2004                             BSD