form_hook(3x) — Linux manual page

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, 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 return one of the following:

       E_OK The routine succeeded.

       E_SYSTEM_ERROR
            System error occurred (see errno(3)).

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
       supported on Version 7 or BSD versions.

AUTHORS

       Juergen Pfeifer.  Manual pages and adaptation for new curses by
       Eric S. Raymond.

COLOPHON

       This page is part of the ncurses (new curses) project.
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       ⟨https://www.gnu.org/software/ncurses/ncurses.html⟩.  If you have
       a bug report for this manual page, send it to
       bug-ncurses-request@gnu.org.  This page was obtained from the
       project's upstream Git mirror of the CVS repository
       ⟨https://github.com/mirror/ncurses.git⟩ on 2024-06-14.  (At that
       time, the date of the most recent commit that was found in the
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                                                           form_hook(3X)