ncurses 6.2 - patch 20201003

[ncurses.git] / man / form_field_buffer.3x

diff --git a/man/form_field_buffer.3x b/man/form_field_buffer.3x
index cac6a088e5ed4581c75bcb6934d704e5dde7d625..cf71d00d7d2775517356cd0bfcc315b1d608bc2e 100644 (file)
--- a/man/form_field_buffer.3x
+++ b/man/form_field_buffer.3x
@@ -1,6 +1,7 @@
 '\" t
 .\"***************************************************************************
 '\" t
 .\"***************************************************************************

-.\" Copyright (c) 1998-2005,2006 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            *
 .\"                                                                          *
 .\" 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.                                                           *
 .\"***************************************************************************
 .\"
 .\" authorization.                                                           *
 .\"***************************************************************************
 .\"

-.\" $Id: form_field_buffer.3x,v 1.14 2006/11/04 17:12:00 tom Exp $
+.\" $Id: form_field_buffer.3x,v 1.26 2020/03/28 19:06:28 tom Exp $

 .TH form_field_buffer 3X ""
 .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
 .SH NAME

-\fBform_field_buffer\fR - field buffer control
+\fBform_field_buffer\fR \- field buffer control

 .SH SYNOPSIS
 \fB#include <form.h>\fR
 .SH SYNOPSIS
 \fB#include <form.h>\fR

-.br
+.sp

 int set_field_buffer(FIELD *field, int buf, const char *value);
 .br
 char *field_buffer(const FIELD *field, int buffer);
 int set_field_buffer(FIELD *field, int buf, const char *value);
 .br
 char *field_buffer(const FIELD *field, int buffer);


@@ -46,27 +55,51 @@ 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
 .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
 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 do not 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
 .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.
 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:
+It sets \fBerrno\fP according to their success:

 .TP 5
 .B E_OK
 The routine succeeded.
 .TP 5
 .B E_OK
 The routine succeeded.


@@ -82,31 +115,30 @@ The remaining routines return one of the following:
 The routine succeeded.
 .TP 5
 .B E_SYSTEM_ERROR
 The routine succeeded.
 .TP 5
 .B E_SYSTEM_ERROR

-System error occurred (see \fBerrno\fR).
+System error occurred (see \fBerrno\fR(3)).

 .TP 5
 .B E_BAD_ARGUMENT
 Routine detected an incorrect or out-of-range argument.
 .SH SEE ALSO
 .TP 5
 .B E_BAD_ARGUMENT
 Routine detected an incorrect or out-of-range argument.
 .SH SEE ALSO

-\fBcurses\fR(3X) and related 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
 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
+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
 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
+These routines emulate the System V forms library.
+They were not supported on

 Version 7 or BSD versions.
 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
 .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.