libc/xcurses/unctrl.c

	unctrl.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 1995-1998 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

/* LINTLIBRARY */

/*
 * unctrl.c
 *
 * XCurses Library
 *
 * Copyright 1990, 1995 by Mortice Kern Systems Inc.  All rights reserved.
 *
 */

#if M_RCSID
#ifndef lint
static char rcsID[] =
"$Header: /team/ps/sun_xcurses/archive/local_changes/xcurses/src/lib/"
"libxcurses/src/libc/xcurses/rcs/unctrl.c 1.3 1998/05/29 15:58:55 "
"cbates Exp $";
#endif
#endif

#include <private.h>
#include <limits.h>
#include <ctype.h>

static const char *carat[] = {
    "^?",
    "^@",
    "^A",
    "^B",
    "^C",
    "^D",
    "^E",
    "^F",
    "^G",
    "^H",
    "^I",
    "^J",
    "^K",
    "^L",
    "^M",
    "^N",
    "^O",
    "^P",
    "^Q",
    "^R",
    "^S",
    "^T",
    "^U",
    "^V",
    "^W",
    "^X",
    "^Y",
    "^Z",
    "^[",
    "^\\",
    "^]",
    "^^",
    "^_"
};

char *
unctrl(chtype ch)
{
    char    *str;
    int c, msb;
    static char chr[5];


    /* Map wide character to a wide string. */
    c = (int)(ch & A_CHARTEXT);
    msb = 1 << (CHAR_BIT-1);

    if (c & ~((1 << CHAR_BIT) - 1)) {
        /* Only know about single-byte characters I guess ... */
        return (NULL);
    }
    if (iscntrl(c)) {
        /* ASCII DEL */
        if (c == 127)
            return ((char *)carat[0]);

        /* ASCII control codes. */
        if (0 <= c && c < 32)
            return ((char *)carat[c+1]);

        /* Something we don't know what to do with. */
        return (NULL);
    } else if (c & msb) {
        /* Meta key notation if high bit is set on character. */
        c &= ~msb;

        chr[0] = 'M';
        chr[1] = '-';

        if (iscntrl(c)) {
            str = (char *) unctrl(c);
            chr[2] = *str++;
            chr[3] = *str;
            chr[4] = '\0';
        } else {
            chr[2] = (char)c;
            chr[3] = '\0';
        }
    } else {
        /* Return byte as is. */
        chr[0] = (char)c;
        chr[1] = '\0';
    }

    return (chr);
}