form_hook(3X)                  DG/UX R4.11MU05                 form_hook(3X)


NAME
       form_hook:  set_form_init, form_init, set_form_term, form_term,
       set_field_init, field_init, set_field_term, field_term - assign
       application-specific routines for invocation by forms

SYNOPSIS
       #include <form.h>

       int set_form_init(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) form_init(FORM *form);
       int set_form_term(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) form_term(FORM *form);
       int set_field_init(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) field_init(FORM *form);
       int set_field_term(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) field_term(FORM *form);

DESCRIPTION
       These routines allow the programmer to assign application specific
       routines to be executed automatically at initialization and
       termination points in the forms application.  The user need not
       specify any application-defined initialization or termination
       routines at all, but they may be helpful for displaying messages or
       page numbers and other chores.

       set_form_init assigns an application-defined initialization function
       to be called when the form is posted and just after a page change.
       form_init returns a pointer to the initialization function, if any.

       set_form_term assigns an application-defined function to be called
       when the form is unposted and just before a page change.  form_term
       returns a pointer to the function, if any.

       set_field_init assigns an application-defined function to be called
       when the form is posted and just after the current field changes.
       field_init returns a pointer to the function, if any.

       set_field_term assigns an application-defined function to be called
       when the form is unposted and just before the current field changes.
       field_term returns a pointer to the function, if any.

RETURN VALUE
       Routines that return pointers always return NULL on error.  Routines
       that return an integer return one of the following:
       E_OK           - The function returned successfully.
       E_SYSTEM_ERROR - System error.

NOTES
       The header file <form.h> automatically includes the header files
       <eti.h> and <curses.h>.

SEE ALSO
       curses(3X), forms(3X).


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