form(3X)

NAME
form - curses extension for programming forms

SYNOPSIS
#include <form.h>

DESCRIPTION
The form library provides terminal-independent facilities for composing form screens on character-cell terminals. The library includes: field routines, which create and modify form fields; and form routines, which group fields into forms, display forms on the screen, and handle interaction with the user.

The form library uses the curses libraries. To use the form library, link with the options -lform -lcurses.

Your program should set up the locale, e.g.,

     setlocale(LC_ALL, "");

so that input/output processing will work.

A curses initialization routine such as initscr must be called before using any of these functions.

  Current Default Values for Field Attributes
The form library maintains a default value for field attributes. You can get or set this default by calling the appropriate set_ or retrieval routine with a NULL field pointer. Changing this default with a set_ function affects future field creations, but does not change the rendering of fields already created.

  Routine Name Index
The following table lists each form routine and the name of the manual page on which it is described. Routines flagged with “*” are ncurses-specific, not present in SVr4.
curses Routine Name | Manual Page Name
current_field | form_page(3X)
data_ahead | form_data(3X)
data_behind | form_data(3X)
dup_field | form_field_new(3X)
dynamic_field_info | form_field_info(3X)
field_arg | form_field_validation(3X)
field_back | form_field_attributes(3X)
field_buffer | form_field_buffer(3X)
field_count | form_field(3X)
field_fore | form_field_attributes(3X)
field_index | form_page(3X)
field_info | form_field_info(3X)
field_init | form_hook(3X)
field_just | form_field_just(3X)
field_opts | form_field_opts(3X)
field_opts_off | form_field_opts(3X)
field_opts_on | form_field_opts(3X)
field_pad | form_field_attributes(3X)
field_status | form_field_buffer(3X)
field_term | form_hook(3X)
field_type | form_field_validation(3X)
field_userptr | form_field_userptr(3X)
form_driver | form_driver(3X)
form_driver_w | form_driver(3X)*
form_fields | form_field(3X)
form_init | form_hook(3X)
form_opts | form_opts(3X)
form_opts_off | form_opts(3X)
form_opts_on | form_opts(3X)
form_page | form_page(3X)
form_request_by_name | form_requestname(3X)*
form_request_name | form_requestname(3X)*
form_sub | form_win(3X)
form_term | form_hook(3X)
form_userptr | form_userptr(3X)
form_win | form_win(3X)
free_field | form_field_new(3X)
free_fieldtype | form_fieldtype(3X)
free_form | form_new(3X)
link_field | form_field_new(3X)
link_fieldtype | form_fieldtype(3X)
move_field | form_field(3X)
new_field | form_field_new(3X)
new_fieldtype | form_fieldtype(3X)
new_form | form_new(3X)
new_page | form_new_page(3X)
pos_form_cursor | form_cursor(3X)
post_form | form_post(3X)
scale_form | form_win(3X)
set_current_field | form_page(3X)
set_field_back | form_field_attributes(3X)
set_field_buffer | form_field_buffer(3X)
set_field_fore | form_field_attributes(3X)
set_field_init | form_hook(3X)
set_field_just | form_field_just(3X)
set_field_opts | form_field_opts(3X)
set_field_pad | form_field_attributes(3X)
set_field_status | form_field_buffer(3X)
set_field_term | form_hook(3X)
set_field_type | form_field_validation(3X)
set_field_userptr | form_field_userptr(3X)
set_fieldtype_arg | form_fieldtype(3X)
set_fieldtype_choice | form_fieldtype(3X)
set_form_fields | form_field(3X)
set_form_init | form_hook(3X)
set_form_opts | form_field_opts(3X)
set_form_page | form_page(3X)
set_form_sub | form_win(3X)
set_form_term | form_hook(3X)
set_form_userptr | form_userptr(3X)
set_form_win | form_win(3X)
set_max_field | form_field_buffer(3X)
set_new_page | form_new_page(3X)
unfocus_current_field | form_page(3X)*
unpost_form | form_post(3X)

RETURN VALUE
Routines that return pointers return NULL on error, and set errno to the corresponding error-code returned by functions returning an integer. Routines that return an integer return one of the following error codes:

E_OK
    The routine succeeded.

E_BAD_ARGUMENT
    Routine detected an incorrect or out-of-range argument.

E_BAD_STATE
    Routine was called from an initialization or termination function.

E_CONNECTED
    The field is already connected to a form.

E_INVALID_FIELD
    Contents of a field are not valid.

E_NOT_CONNECTED
    No fields are connected to the form.

E_NOT_POSTED
    The form has not been posted.

E_NO_ROOM
    Form is too large for its window.

E_POSTED
    The form is already posted.

E_REQUEST_DENIED
    The form driver could not process the request.

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

E_UNKNOWN_COMMAND
    The form driver code saw an unknown request code.

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

In your library list, libform.a should be before libncurses.a; that is, you want to say “-lform -lncurses”, not the other way around (which would give you a link error when using static libraries).

PORTABILITY
These routines emulate the System V forms library. They were not supported on Version 7 or BSD versions.

The menu facility was documented in SVr4.2 in Character User Interface Programming (UNIX SVR4.2).

It is not part of X/Open Curses.

Aside from ncurses, there are few implementations: systems based on SVr4 source code, e.g., Solaris. NetBSD curses.

A few functions in this implementation are extensions added for ncurses, but not provided by other implementations, e.g., form_driver_w, unfocus_current_field.

AUTHORS
Juergen Pfeifer. Manual pages and adaptation for ncurses by Eric S. Raymond.

SEE ALSO
curses(3X) and related pages whose names begin “form_” for detailed descriptions of the entry points.

This describes ncurses version 6.4 (patch 20230708).