FORMS(3)

FORMS(3) | Library Functions Manual | FORMS(3)

# NAME

`free_fieldtype`, `link_fieldtype`, `new_fieldtype`, `set_fieldtype_arg`, `set_fieldtype_choice` —
form library

# LIBRARY

Curses Form Library (libform, -lform)

# SYNOPSIS

`#include <form.h>`

int
`free_fieldtype`(FIELDTYPE *fieldtype);

FIELDTYPE *
`link_fieldtype`(FIELDTYPE *type1, FIELDTYPE *type2);

FIELDTYPE *
`new_fieldtype`(int (*field_check)(FIELD *, char *), int (*char_check)(int, char *));

int
`set_fieldtype_arg`(FIELDTYPE *fieldtype, char * (*make_args)(va_list *), char * (*copy_args)(char *), void (*free_args)(char *));

int
`set_fieldtype_choice`(FIELDTYPE *fieldtype, int (*next_choice)(FIELD *, char *), int (*prev_choice)(FIELD *, char *));

# DESCRIPTION

The function `free_fieldtype`() frees the storage associated with the field type and destroys it. The function `link_fieldtype`() links together the two given field types to produce a new field type. A new field type can be created by calling `new_fieldtype`() which requires pointers to two functions which perform validation, the field_check function must validate the field contents and return `TRUE` if they are acceptable and `FALSE` if they are not. The char_check validates the character input into the field, this function will be called for each character entered, if the character can be entered into the field then char_check must return `TRUE`. Neither field_check nor char_check may be `NULL`. The functions for handling the field type arguments can be defined by using the `set_fieldtype_arg`() function, the make_args function is used to create new arguments for the fieldtype, the copy_args is used to copy the fieldtype arguments to a new arguments structure and free_args is used to destroy the fieldtype arguments and release any associated storage, none of these function pointers may be `NULL`. The field type choice functions can be set by calling `set_fieldtype_choice`(), the next_choice and prev_choice specify the next and previous choice functions for the field type. These functions must perform the necessary actions to select the next or previous choice for the field, updating the field buffer if necessary. The choice functions must return `TRUE` if the function succeeded and `FALSE` otherwise.

# RETURN VALUES

Functions returning pointers will return `NULL` if an error is detected. The functions that return an int will return one of the following error values:

`E_OK`
  The function was successful.
`E_BAD_ARGUMENT`
  The function was passed a bad argument.
`E_CONNECTED`
  The field is connected to a form.

# SEE ALSO

curses(3), forms(3)

# NOTES

The header `<form.h>` automatically includes both `<curses.h>` and `<eti.h>`.

January 1, 2001 | NetBSD 9.0