'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998-2006,2010 Free Software Foundation, Inc. *
+.\" Copyright 2018-2019,2020 Thomas E. Dickey *
+.\" Copyright 1998-2006,2010 Free Software Foundation, Inc. *
.\" *
.\" Permission is hereby granted, free of charge, to any person obtaining a *
.\" copy of this software and associated documentation files (the *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: form_fieldtype.3x,v 1.16 2010/12/04 18:40:45 tom Exp $
+.\" $Id: form_fieldtype.3x,v 1.21 2020/03/28 19:06:28 tom Exp $
.TH form_fieldtype 3X ""
.SH NAME
\fBform_fieldtype\fR \- define validation-field types
.br
.SH DESCRIPTION
The function \fBnew_fieldtype\fR creates a new field type usable for data
-validation. You supply it with \fIfield_check\fR, a predicate to check the
+validation.
+You supply it with \fIfield_check\fR, a predicate to check the
validity of an entered data string whenever the user attempts to leave a field.
The (FIELD *) argument is passed in so the validation predicate can see the
field's buffer, sizes and other attributes; the second argument is an
The function \fBfree_fieldtype\fR frees the space allocated for a given
validation type.
.PP
-The function \fBset_fieldtype_arg\fR associates three storage-management functions
-with a field type.
+The function \fBset_fieldtype_arg\fR associates
+three storage-management functions with a field type.
The \fImake_arg\fR function is automatically applied to the
list of arguments you give \fBset_field_type\fR when attaching validation
to a field; its job is to bundle these into an allocated argument-block
argument-block structure as arguments.
.SH RETURN VALUE
The pointer-valued routines return NULL on error.
-They set errno according to their success:
+They set \fBerrno\fP according to their success:
.TP 5
.B E_OK
The routine succeeded.
The field is the current field.
.TP 5
.B E_SYSTEM_ERROR
-System error occurred (see \fBerrno\fR).
+System error occurred (see \fBerrno\fR(3)).
.SH SEE ALSO
\fBcurses\fR(3X), \fBform\fR(3X).
.SH NOTES
\fB(void *)\fR. The type has been left uncorrected for strict compatibility
with System V.
.SH PORTABILITY
-These routines emulate the System V forms library. They were not supported on
+These routines emulate the System V forms library.
+They were not supported on
Version 7 or BSD versions.
.SH AUTHORS
-Juergen Pfeifer. Manual pages and adaptation for new curses by Eric
-S. Raymond.
+Juergen Pfeifer.
+Manual pages and adaptation for new curses by Eric S. Raymond.