X-Git-Url: https://ncurses.scripts.mit.edu/?a=blobdiff_plain;ds=inline;f=man%2Fform_field_buffer.3x;h=cf71d00d7d2775517356cd0bfcc315b1d608bc2e;hb=e8c3445229c546ba14ea2992da4d93a9d31914f8;hp=202d4e7e0da5db2bc16328b19ba30a7de0d84ad8;hpb=0eb88fc5281804773e2a0c7a488a4452463535ce;p=ncurses.git
diff --git a/man/form_field_buffer.3x b/man/form_field_buffer.3x
index 202d4e7e..cf71d00d 100644
--- a/man/form_field_buffer.3x
+++ b/man/form_field_buffer.3x
@@ -1,6 +1,7 @@
'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998 Free Software Foundation, Inc. *
+.\" Copyright 2018-2019,2020 Thomas E. Dickey *
+.\" Copyright 1998-2010,2017 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 *
@@ -27,13 +28,21 @@
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: form_field_buffer.3x,v 1.8 1999/06/16 00:37:09 juergen Exp $
+.\" $Id: form_field_buffer.3x,v 1.26 2020/03/28 19:06:28 tom Exp $
.TH form_field_buffer 3X ""
+.ie \n(.g .ds `` \(lq
+.el .ds `` ``
+.ie \n(.g .ds '' \(rq
+.el .ds '' ''
+.de bP
+.ie n .IP \(bu 4
+.el .IP \(bu 2
+..
.SH NAME
-\fBform_field_buffer\fR - field buffer control
+\fBform_field_buffer\fR \- field buffer control
.SH SYNOPSIS
\fB#include
\fR
-.br
+.sp
int set_field_buffer(FIELD *field, int buf, const char *value);
.br
char *field_buffer(const FIELD *field, int buffer);
@@ -46,54 +55,90 @@ int set_max_field(FIELD *field, int max);
.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
+.bP
+Buffer 0 is the displayed value of the field.
+.bP
+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
+.bP
+The buffer contents always have the same length,
+and are padded with trailing spaces
+as needed to ensure this length is the same.
+.bP
+The buffer may contain leading spaces, depending on how it was set.
+.bP
+The buffer contents are set with \fBset_field_buffer\fP,
+or as a side effect of any editing operations on the corresponding field.
+.bP
+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.
+.bP
+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
+\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 \fBerrno\fP 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
-System error occurred (see \fBerrno\fR).
+.B E_SYSTEM_ERROR
+System error occurred (see \fBerrno\fR(3)).
.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\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\fR.
.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.
+.PP
+The \fBset_max_field\fP function checks for an ncurses extension
+\fBO_INPUT_FIELD\fP which allows a dynamic field to shrink if the new
+limit is smaller than the current field size.
.SH AUTHORS
-Juergen Pfeifer. Manual pages and adaptation for new curses by Eric
-S. Raymond.
-.\"#
-.\"# The following sets edit modes for GNU EMACS
-.\"# Local Variables:
-.\"# mode:nroff
-.\"# fill-column:79
-.\"# End:
+Juergen Pfeifer.
+Manual pages and adaptation for new curses by Eric S. Raymond.