-'\" t
.\"***************************************************************************
-.\" Copyright (c) 1998-2004,2005 Free Software Foundation, Inc. *
+.\" Copyright 2018-2023,2024 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 *
.\" authorization. *
.\"***************************************************************************
.\"
-.\" $Id: form_field_buffer.3x,v 1.12 2005/05/15 15:59:55 tom Exp $
-.TH form_field_buffer 3X ""
+.\" $Id: form_field_buffer.3x,v 1.45 2024/03/16 15:35:01 tom Exp $
+.TH form_field_buffer 3X 2024-03-16 "ncurses @NCURSES_MAJOR@.@NCURSES_MINOR@" "Library calls"
+.ie \n(.g \{\
+.ds `` \(lq
+.ds '' \(rq
+.\}
+.el \{\
+.ie t .ds `` ``
+.el .ds `` ""
+.ie t .ds '' ''
+.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\fP \-
+field buffer control
.SH SYNOPSIS
-\fB#include <form.h>\fR
-.br
-int set_field_buffer(FIELD *field, int buf, const char *value);
-.br
-char *field_buffer(const FIELD *field, int buffer);
-.br
-int set_field_status(FIELD *field, bool status);
-.br
-bool field_status(const FIELD *field);
-.br
-int set_max_field(FIELD *field, int max);
-.br
+.nf
+\fB#include <form.h>
+.PP
+\fBint set_field_buffer(FIELD *\fIfield\fP, int \fIbuf\fP, const char *\fIvalue\fP);
+\fBchar *field_buffer(const FIELD *\fIfield\fP, int \fIbuffer\fP);
+.PP
+\fBint set_field_status(FIELD *\fIfield\fP, bool \fIstatus\fP);
+\fBbool field_status(const FIELD *\fIfield\fP);
+.PP
+\fBint set_max_field(FIELD *\fIfield\fP, int \fImax\fP);
+.fi
.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
+The function \fBset_field_buffer\fP sets the numbered buffer of the given field
+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\fP
+argument of (see \fBform_field_new\fP(3X))
+but are not manipulated by the forms library.
+.RE
+.PP
+The function \fBfield_buffer\fP 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 do not use it for long term
-storage of the entered form data.
-
-The function \fBset_field_status\fR sets the associated status flag of
-\fIfield\fR; \fBfield_status\fR gets the current value. The status flag
+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\fP sets the associated status flag of
+\fIfield\fP; \fBfield_status\fP gets the current value.
+The status flag
is set to a nonzero value whenever the field changes.
-
-The function \fBset_max_field\fR sets the maximum size for a dynamic field.
+.PP
+The function \fBset_max_field\fP 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.
-
-The \fBfield_status\fR function returns \fBTRUE\fR or \fBFALSE\fR.
-
+The \fBfield_buffer\fP 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\fP function returns \fBTRUE\fP or \fBFALSE\fP.
+.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\fP(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 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
-
-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
-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 \fI\%ncurses\fP 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.
+.SH SEE ALSO
+\fB\%curses\fP(3X) and related pages whose names begin \*(``form_\*(''
+for detailed descriptions of the entry points.
projects / ncurses.git / blobdiff