1.\" $NetBSD: form_hook.3,v 1.10 2010/03/22 21:58:31 joerg Exp $ 2.\" 3.\" Copyright (c) 2001 4.\" Brett Lymn - blymn@baea.com.au, brett_lymn@yahoo.com.au 5.\" 6.\" This code is donated to The NetBSD Foundation by the author. 7.\" 8.\" Redistribution and use in source and binary forms, with or without 9.\" modification, are permitted provided that the following conditions 10.\" are met: 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 2. Redistributions in binary form must reproduce the above copyright 14.\" notice, this list of conditions and the following disclaimer in the 15.\" documentation and/or other materials provided with the distribution. 16.\" 3. The name of the Author may not be used to endorse or promote 17.\" products derived from this software without specific prior written 18.\" permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.Dd January 1, 2001 33.Dt FORMS 3 34.Os 35.Sh NAME 36.Nm field_init , 37.Nm field_term , 38.Nm form_init , 39.Nm form_term , 40.Nm set_field_init , 41.Nm set_field_term , 42.Nm set_form_init , 43.Nm set_form_term 44.Nd form library 45.Sh LIBRARY 46.Lb libform 47.Sh SYNOPSIS 48.In form.h 49.Ft void (*)(FORM *) 50.Fn field_init "FORM *form" 51.Ft void (*)(FORM *) 52.Fn field_term "FORM *form" 53.Ft void (*)(FORM *) 54.Fn form_init "FORM *form" 55.Ft void (*)(FORM *) 56.Fn form_term "FORM *form" 57.Ft int 58.Fn set_field_init "FORM *form" "void (*function)(FORM *)" 59.Ft int 60.Fn set_field_term "FORM *form" "void (*function)(FORM *)" 61.Ft int 62.Fn set_form_init "FORM *form" "void (*function)(FORM *)" 63.Ft int 64.Fn set_form_term "FORM *form" "void (*function)(FORM *)" 65.Sh DESCRIPTION 66The 67.Fn field_init 68function returns a pointer to the function that will be called just 69after the current field changes and just before the form is posted, 70this function may be set by using the 71.Fn set_field_init 72function. 73Similarly, the function 74.Fn field_term 75will return a pointer to the function that will be called just before 76the current field changes and just after the form is unposted, this 77function pointer may be set by using the 78.Fn set_field_term 79function. 80The 81.Fn form_init 82function will return a pointer to the function that will be called 83just before the form is posted to the screen, this function can be set 84by calling the 85.Fn set_form_init 86function. 87The 88.Fn form_term 89function will return a pointer to the function that will be called 90just after the form is unposted from the screen, this function may be 91set by using the 92.Fn set_form_term 93function. 94By default, the init and term function pointers are 95.Dv NULL . 96.Sh RETURN VALUES 97Functions returning pointers will return 98.Dv NULL 99if an error is detected. 100The functions that return an int will return one of the following error 101values: 102.Pp 103.Bl -tag -width E_UNKNOWN_COMMAND -compact 104.It Er E_OK 105The function was successful. 106.El 107.Sh SEE ALSO 108.Xr curses 3 , 109.Xr forms 3 110.Sh NOTES 111The header 112.In form.h 113automatically includes both 114.In curses.h 115and 116.In eti.h . 117