'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998 Free Software Foundation, Inc. *
+.\" Copyright (c) 1998-2008,2010 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_field_buffer.3x,v 1.8 1999/06/16 00:37:09 juergen Exp $
+.\" $Id: form_field_buffer.3x,v 1.16 2010/07/31 16:09:36 tom Exp $
.TH form_field_buffer 3X ""
.SH NAME
-\fBform_field_buffer\fR - field buffer control
+\fBform_field_buffer\fR \- field buffer control
.SH SYNOPSIS
\fB#include <form.h>\fR
.br
.br
.SH DESCRIPTION
The function \fBset_field_buffer\fR sets the numbered buffer of the given field
-to contain a given string. Buffer 0 is the displayed value of the field; other
-numbered buffers may be allocated by applications through the \fBnbuf\fR
-argument of (see \fBform_field_new\fR(3X)) but are not manipulated by the forms
-library. The function \fBfield_buffer\fR returns the address of the buffer.
-Please note that this buffer has always the length of the buffer, that means
-that it may typically contain trailing spaces. If you entered leading spaces
-the buffer may also contain them. If you want the raw data, you must write your
+to contain a given string:
+.RS 3
+.TP 3
+\-
+Buffer 0 is the displayed value of the field.
+.TP 3
+\-
+Other numbered buffers may be allocated by applications through the \fBnbuf\fR
+argument of (see \fBform_field_new\fR(3X))
+but are not manipulated by the forms library.
+.RE
+.PP
+The function \fBfield_buffer\fR returns a pointer to
+the contents of the given numbered buffer:
+.RS 3
+.TP 3
+\-
+The buffer contents always have the same length,
+and are padded with trailing spaces
+as needed to ensure this length is the same.
+.TP 3
+\-
+The buffer may contain leading spaces, depending on how it was set.
+.TP 3
+\-
+The buffer contents are set with \fBset_field_buffer\fP,
+or as a side effect of any editing operations on the corresponding field.
+.TP 3
+\-
+Editing operations are based on the \fIwindow\fP which displays the field,
+rather than a \fIstring\fP.
+The window contains only printable characters, and is filled with blanks.
+If you want the raw data, you must write your
own routine that copies the value out of the buffer and removes the leading
-and trailing spaces. Please note also, that subsequent operations on the form
-will probably change the content of the buffer. So don't use it for long term
-storage of the entered form data.
-
+and trailing spaces.
+.TP 3
+\-
+Because editing operations change the content of the buffer to
+correspond to the window, you should not rely on using buffers
+for long-term storage of form data.
+.RE
+.PP
The function \fBset_field_status\fR sets the associated status flag of
\fIfield\fR; \fBfield_status\fR gets the current value. The status flag
is set to a nonzero value whenever the field changes.
-
+.PP
The function \fBset_max_field\fR sets the maximum size for a dynamic field.
An argument of 0 turns off any maximum size threshold for that field.
.SH RETURN VALUE
The \fBfield_buffer\fR function returns NULL on error.
-
+It sets errno according to their success:
+.TP 5
+.B E_OK
+The routine succeeded.
+.TP 5
+.B E_BAD_ARGUMENT
+Routine detected an incorrect or out-of-range argument.
+.PP
The \fBfield_status\fR function returns \fBTRUE\fR or \fBFALSE\fR.
-
+.PP
The remaining routines return one of the following:
.TP 5
-\fBE_OK\fR
+.B E_OK
The routine succeeded.
.TP 5
-\fBE_SYSTEM_ERROR\fR
+.B E_SYSTEM_ERROR
System error occurred (see \fBerrno\fR).
.TP 5
-\fBE_BAD_ARGUMENT\fR
+.B E_BAD_ARGUMENT
Routine detected an incorrect or out-of-range argument.
.SH SEE ALSO
-\fBcurses\fR(3X) and 3X pages whose names begin "form_" for detailed
+\fBcurses\fR(3X) and related pages whose names begin "form_" for detailed
descriptions of the entry points.
.SH NOTES
The header file \fB<form.h>\fR automatically includes the header file
+.PP
+When configured for wide-characters, \fBfield_buffer\fP returns a pointer
+to temporary storage (allocated and freed by the library).
+The application should not attempt to modify the data.
+It will be freed on the next call to \fBfield_buffer\fP to return the
+same buffer.
\fB<curses.h>\fR.
.SH PORTABILITY
These routines emulate the System V forms library. They were not supported on
projects / ncurses.git / blobdiff