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.

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.

See attributes(5) for descriptions of the following attributes:

curses(3CURSES), forms(3CURSES), attributes(5)

The header <form.h> automatically includes the headers <eti.h> and <curses.h>.