minix/lib/libform/form_field_buffer.3

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.\" $NetBSD: form_field_buffer.3,v 1.13 2010/03/22 21:58:31 joerg Exp $
.\"
.\" Copyright (c) 2001
.\" Brett Lymn - blymn@baea.com.au, brett_lymn@yahoo.com.au
.\"
.\" This code is donated to The NetBSD Foundation by the author.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\" notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\" notice, this list of conditions and the following disclaimer in the
.\" documentation and/or other materials provided with the distribution.
.\" 3. The name of the Author may not be used to endorse or promote
.\" products derived from this software without specific prior written
.\" permission.
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.Dd October 15, 2005
.Dt FORMS 3
.Os
.Sh NAME
.Nm field_buffer ,
.Nm field_status ,
.Nm set_field_buffer ,
.Nm set_field_printf ,
.Nm set_field_status ,
.Nm set_max_field
.Nd form library
.Sh LIBRARY
.Lb libform
.Sh SYNOPSIS
.In form.h
.Ft char *
.Fn field_buffer "FIELD *field" "int buffer"
.Ft int
.Fn field_status "FIELD *field"
.Ft int
.Fn set_field_buffer "FIELD *field" "int buffer" "char *value"
.Ft int
.Fn set_field_printf "FIELD *field" "int buffer" "char *fmt" "..."
.Ft int
.Fn set_field_status "FIELD *field" "int status"
.Ft int
.Fn set_max_field "FIELD *field" "int max"
.Sh DESCRIPTION
The
.Fn field_buffer
function returns the contents of the buffer number specified by
.Fa buffer
for the given field.
If the requested buffer number exceeds the
number of buffers attached to the field then
.Dv NULL
will be returned.
If the field option
.Dv O_REFORMAT
is enabled on the given field then
storage will be allocated to hold the reformatted buffer.
This storage must be release by calling
.Xr free 3
when it is no longer required.
If the
.Dv O_REFORMAT
field option is not set then no extra storage is allocated.
The field buffer may be set by calling
.Fn set_field_buffer
which will set the given buffer number to the contents of the string
passed.
A buffer may also be set by calling
.Fn set_field_printf
which sets the buffer using the format arg
.Fa fmt
after being expanded using the subsequent arguments in the same manner
as
.Xr sprintf 3
does.
Calling
.Fn field_status
will return the status of the first buffer attached to the field.
If the field has been modified then the function will return
.Dv TRUE
otherwise
.Dv FALSE
is returned, the status of the first buffer may be
programmatically set by calling
.Fn set_field_status .
The maximum growth of a dynamic field can be set by calling
.Fn set_max_field
which limits the fields rows if the field is a multiline field or the
fields columns if the field only has a single row.
.Sh RETURN VALUES
Functions returning pointers will return
.Dv NULL
if an error is detected.
The functions that return an int will return one of the following error
values:
.Pp
.Bl -tag -width E_UNKNOWN_COMMAND -compact
.It Er E_OK
The function was successful.
.It Er E_BAD_ARGUMENT
A bad parameter was passed to the function.
.It Er E_SYSTEM_ERROR
A system error occurred performing the function.
.El
.Sh SEE ALSO
.Xr curses 3 ,
.Xr forms 3
.Sh NOTES
The header
.In form.h
automatically includes both
.In curses.h
and
.In eti.h .
The function
.Fn set_field_printf
is a
.Nx
extension and must not be used in portable code.