form_hook

form_hook(3X)                                                    form_hook(3X)



NAME
       form_hook - set hooks for automatic invocation by applications

SYNOPSIS
       #include <form.h>
       int set_field_init(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) field_init(const FORM *form);
       int set_field_term(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) field_term(const FORM *form);
       int set_form_init(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) form_init(const FORM *form);
       int set_form_term(FORM *form, void (*func)(FORM *));
       void (*)(FORM *) 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
       return one of the following:

       E_OK The routine succeeded.

       E_SYSTEM_ERROR
            System error occurred (see errno).

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

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.



                                                                 form_hook(3X)