FORMS(3) Library Functions Manual FORMS(3)
form -- form library
Curses Form Library (libform, -lform)
The form library provides a terminal independent form system using the
curses(3) library. Before using the form functions the terminal must be
set up by curses(3) using the initscr() function or similar. Programs
using form functions must be linked with the curses(3) library -lcurses.
The form library provides facilities for defining form fields, placing a
form on the terminal screen, assign pre and post change operations and
setting the attributes of both the form and its fields.
Defining default attributes for forms and fields
The form library allows any settable attribute or option of both the form
and field objects to be defined such that any new form or field
automatically inherits the value as default. Setting the default value
will not affect any field or form that has already been created but will
be applied to subsequent objects. To set the default attribute or option
the set routine is passed a NULL pointer in the field or form parameter
when calling the set routine. The current default value can be retrieved
by calling the get routine with a NULL pointer for the field or form
Form Routine Name Manual Page Name
Any function returning a string pointer will return NULL if an error
occurs. Functions returning an integer will return one of the following:
E_OK The function was successful.
E_SYSTEM_ERROR There was a system error during the call.
E_BAD_ARGUMENT One or more of the arguments passed to the
function was incorrect.
E_POSTED The form is already posted.
E_CONNECTED A field was already connected to a form.
E_BAD_STATE The function was called from within an
initialization or termination routine.
E_NO_ROOM The form does not fit within the subwindow.
E_NOT_POSTED The form is not posted.
E_UNKNOWN_COMMAND The form driver does not recognize the request
passed to it.
E_NOT_SELECTABLE The field could not be selected.
E_NOT_CONNECTED The field is not connected to a form.
E_REQUEST_DENIED The form driver could not process the request.
E_INVALID_FIELD The field is invalid.
E_CURRENT The field is the active one on the form.
This implementation of the forms library does depart in behavior subtly
from the original AT&T implementation. Some of the more notable
field wrapping For multi-line fields the data will be wrapped as it
is entered, this does not happen in the AT&T
buffer 0 In this implementation, the contents of buffer 0 are
always current regardless of whether the field has
been validated or not.
circular fields In the AT&T implementation fields are circular on a
page, that is, a next field from the last field will
go to the first field on the current page. In this
implementation a next field request on the last field
of a page will result in the forms library positioning
the cursor on the first field of the next page. If
the field is the last field in the form then going to
the next field will be denied, in the AT&T it would
result in the cursor being placed on the first field
of the first page.
buffer returns In this implementation only the data entered by the
user in the form field will be returned, unlike the
AT&T library which would return the contents of the
field padded to the size of the field with the pad
The TAB character The handling of the TAB character in fields varies
between implementations. In ncurses attempting to set
a field contents with a string containing a TAB will
result in an error and will not allow a TAB to be
entered into a field. The AT&T library statically
converts tabs to the equivalent number of spaces when
the field buffer is set but the form driver will not
allow a TAB to be inserted into the field buffer.
This implementation allows TAB when setting the field
buffer and also will allow TAB to be inserted into a
field buffer via the form driver and correctly
calculates the cursor position allowing for expansion
of the TAB character.
set_field_printf This function is a NetBSD extension and must not be
used in portable code.
O_REFORMAT This field option is a NetBSD extension and must not
be used in portable code.
NetBSD 6.1.5 November 24, 2004 NetBSD 6.1.5