*** UNIX MANUAL PAGE BROWSER ***

form_hook(3) Library calls form_hook(3) NAME form_hook - set hooks for automatic invocation by applications SYNOPSIS #include <form.h> int set_field_init(FORM *form, Form_Hook func); Form_Hook field_init(const FORM *form); int set_field_term(FORM *form, Form_Hook func); Form_Hook field_term(const FORM *form); int set_form_init(FORM *form, Form_Hook func); Form_Hook form_init(const FORM *form); int set_form_term(FORM *form, Form_Hook func); Form_Hook form_term(const FORM *form); DESCRIPTION These functions make it possible to set hook functions to be called at various points in the automatic processing of input event codes by form_driver. The function set_field_init sets a hook to be called at form-post time and each time the selected field changes (after the change). field_init returns the current field init hook, if any (NULL if there is no such hook). The function set_field_term sets a hook to be called at form-unpost time and each time the selected field changes (before the change). field_term returns the current field term hook, if any (NULL if there is no such hook). The function set_form_init sets a hook to be called at form-post time and just after a page change once it is posted. form_init returns the current form init hook, if any (NULL if there is no such hook). The function set_form_term sets a hook to be called at form-unpost time and just before a page change once it is posted. form_init returns the current form term hook, if any (NULL if there is no such hook). RETURN VALUE Routines that return pointers return NULL on error. Other routines re- turn one of the following: E_OK The routine succeeded. E_SYSTEM_ERROR System error occurred (see errno(3)). SEE ALSO curses(3), form(3). NOTES The header file <form.h> automatically includes the header file <curses.h>. PORTABILITY These routines emulate the System V forms library. They were not sup- ported on Version 7 or BSD versions. AUTHORS Juergen Pfeifer. Manual pages and adaptation for new curses by Eric S. Raymond. ncurses 6.4 2023-07-01 form_hook(3)