form - curses extension for programming forms
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.
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.
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) |
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.
The header file form.h itself includes curses.h.
These routines emulate the System V forms library. They were not
supported on Version 7 or BSD versions.
A form facility was documented in SVr4.2's Character User
Interface Programming document.
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.
Juergen Pfeifer. Manual pages and adaptation for ncurses by
Eric S. Raymond.
curses(3X) and related pages whose names begin
“form_” for detailed descriptions of the entry points.