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form(3) form(3)
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 inter-
action 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.
curses Routine Name Manual Page Name
------------------------------------------------
current_field form_page(3)
data_ahead form_data(3)
data_behind form_data(3)
dup_field form_field_new(3)
dynamic_field_info form_field_info(3)
field_arg form_field_validation(3)
field_back form_field_attributes(3)
field_buffer form_field_buffer(3)
field_count form_field(3)
field_fore form_field_attributes(3)
field_index form_page(3)
field_info form_field_info(3)
field_init form_hook(3)
field_just form_field_just(3)
field_opts form_field_opts(3)
field_opts_off form_field_opts(3)
field_opts_on form_field_opts(3)
field_pad form_field_attributes(3)
field_status form_field_buffer(3)
field_term form_hook(3)
field_type form_field_validation(3)
field_userptr form_field_userptr(3)
form_driver form_driver(3)
form_fields form_field(3)
form_init form_hook(3)
form_opts form_opts(3)
form_opts_off form_opts(3)
form_opts_on form_opts(3)
form_page form_page(3)
form_request_by_name form_requestname(3)
form_request_name form_requestname(3)
form_sub form_win(3)
form_term form_hook(3)
form_userptr form_userptr(3)
form_win form_win(3)
free_field form_field_new(3)
free_fieldtype form_fieldtype(3)
free_form form_new(3)
link_field form_field_new(3)
link_fieldtype form_fieldtype(3)
move_field form_field(3)
new_field form_field_new(3)
new_fieldtype form_fieldtype(3)
new_form form_new(3)
new_page form_new_page(3)
pos_form_cursor form_cursor(3)
post_form form_post(3)
scale_form form_win(3)
set_current_field form_page(3)
set_field_back form_field_attributes(3)
set_field_buffer form_field_buffer(3)
set_field_fore form_field_attributes(3)
set_field_init form_hook(3)
set_field_just form_field_just(3)
set_field_opts form_field_opts(3)
set_field_pad form_field_attributes(3)
set_field_status form_field_buffer(3)
set_field_term form_hook(3)
set_field_type form_field_validation(3)
set_field_userptr form_field_userptr(3)
set_fieldtype_arg form_fieldtype(3)
set_fieldtype_choice form_fieldtype(3)
set_form_fields form_field(3)
set_form_init form_hook(3)
set_form_opts form_field_opts(3)
set_form_page form_page(3)
set_form_sub form_win(3)
set_form_term form_hook(3)
set_form_userptr form_userptr(3)
set_form_win form_win(3)
set_max_field form_field_buffer(3)
set_new_page form_new_page(3)
unpost_form form_post(3)
RETURN VALUE
Routines that return pointers return NULL on error, and set errno to
the corresponding error-code returned by functions returning an inte-
ger. 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).
E_UNKNOWN_COMMAND
The form driver code saw an unknown request code.
SEE ALSO
curses(3) and related pages whose names begin "form_" for detailed
descriptions of the entry points.
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 using most linkers).
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 ncurses by Eric S.
Raymond.
SEE ALSO
This describes ncurses version @NCURSES_MAJOR@.@NCURSES_MINOR@ (patch
@NCURSES_PATCH@).
form(3)
form_field_validation(3X) form_field_validation(3X)
NAME
form_field_validation - data type validation for fields
SYNOPSIS
#include <form.h>
void *field_arg(const FIELD *field);
FIELDTYPE *field_type(const FIELD *field);
int set_field_type(FIELD *field, FIELDTYPE *type, ...);
/* predefined field types */
FIELDTYPE *TYPE_ALNUM;
FIELDTYPE *TYPE_ALPHA;
FIELDTYPE *TYPE_ENUM;
FIELDTYPE *TYPE_INTEGER;
FIELDTYPE *TYPE_NUMERIC;
FIELDTYPE *TYPE_REGEXP;
FIELDTYPE *TYPE_IPV4;
DESCRIPTION
By default, no validation is done on form fields. You can associate a
form with with a field type, making the form library validate input.
field_arg
Returns a pointer to the field's argument block. The argument block is
an opaque structure containing a copy of the arguments provided in a
set_field_type call.
field_type
Returns a pointer to the field type associated with the form field,
i.e., by calling set_field_type.
set_field_type
The function set_field_type associates a field type with a given form
field. This is the type checked by validation functions. Most field
types are configurable, via arguments which the caller provides when
calling set_field_type.
Several field types are predefined by the form library.
Predefined types
It is possible to set up new programmer-defined field types. Field
types are implemented via the FIELDTYPE data structure, which contains
several pointers to functions.
See the form_fieldtype(3X) manual page, which describes functions which
can be used to construct a field-type dynamically.
The predefined types are as follows:
TYPE_ALNUM
Alphanumeric data. Required parameter:
o a third int argument, a minimum field width.
TYPE_ALPHA
Character data. Required parameter:
o a third int argument, a minimum field width.
TYPE_ENUM
Accept one of a specified set of strings. Required parameters:
o a third (char **) argument pointing to a string list;
o a fourth int flag argument to enable case-sensitivity;
o a fifth int flag argument specifying whether a partial match
must be a unique one. If this flag is off, a prefix matches
the first of any set of more than one list elements with that
prefix.
The library copies the string list, so you may use a list that
lives in automatic variables on the stack.
TYPE_INTEGER
Integer data, parsable to an integer by atoi(3). Required
parameters:
o a third int argument controlling the precision,
o a fourth long argument constraining minimum value,
o a fifth long constraining maximum value. If the maximum value
is less than or equal to the minimum value, the range is
simply ignored.
On return, the field buffer is formatted according to the printf
format specification ".*ld", where the "*" is replaced by the
precision argument.
For details of the precision handling see printf(3).
TYPE_NUMERIC
Numeric data (may have a decimal-point part). Required
parameters:
o a third int argument controlling the precision,
o a fourth double argument constraining minimum value,
o and a fifth double constraining maximum value. If your system
supports locales, the decimal point character must be the one
specified by your locale. If the maximum value is less than
or equal to the minimum value, the range is simply ignored.
On return, the field buffer is formatted according to the printf
format specification ".*f", where the "*" is replaced by the
precision argument.
For details of the precision handling see printf(3).
TYPE_REGEXP
Regular expression data. Required parameter:
o a third argument, a regular expression (char *) string. The
data is valid if the regular expression matches it.
Regular expressions are in the format of regcomp and regexec.
The regular expression must match the whole field. If you have
for example, an eight character wide field, a regular expression
"^[0-9]*$" always means that you have to fill all eight positions
with digits. If you want to allow fewer digits, you may use for
example "^[0-9]* *$" which is good for trailing spaces (up to an
empty field), or "^ *[0-9]* *$" which is good for leading and
trailing spaces around the digits.
TYPE_IPV4
An Internet Protocol Version 4 address. Required parameter:
o none
The form library checks whether or not the buffer has the form
a.b.c.d, where a, b, c, and d are numbers in the range 0 to 255.
Trailing blanks in the buffer are ignored. The address itself is
not validated.
This is an ncurses extension; this field type may not be available
in other curses implementations.
RETURN VALUE
The functions field_type and field_arg return NULL on error. The
function set_field_type returns one of the following:
E_OK The routine succeeded.
E_SYSTEM_ERROR
System error occurred (see errno(3)).
SEE ALSO
curses(3X), form(3X), form_fieldtype(3X), form_variables(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.
form_field_validation(3X)