/*
 * showkey.c -- display cooked key sequences
 *
Copyright (c) 2002, Eric S. Raymond

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to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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furnished to do so, subject to the following conditions:<P>

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.<P>

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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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THE SOFTWARE.<P>

 *
 * Invoke this (no arguments needed) to see keycap-to-keystrokes mappings.
 *
 * by Eric S. Raymond <esr@snark.thyrsus.com>, 1 Nov 88
 * - fix for little-endian machines (version 1.1), 21 Oct 1996.
 * - cleanup and modern packaging (version 1.2), 1 Aug 2002.
 * - changed to use termios (version 1.3), 26 Aug 2002.
 * - typo fix  (version 1.4) 10 Sep 2004.
 */
#include <stdio.h>
#include <termios.h>
#include <signal.h>

#define META	0x80
#define ESC	0x1b

static char *lowchars[] =
{
    "NUL", "SOH", "STX", "ETX", "EOT", "ENQ", "ACK", "BEL",
    "BS",  "HT",  "LF",  "VT",  "FF",  "CR",  "SO",  "SI",
    "DLE", "DC1", "DC2", "DC3", "DC4", "NAK", "SYN", "ETB",
    "CAN", "EM",  "SUB", "ESC", "FS",  "GS",  "RS",  "US",
    "SP",
};

static int signalled;

static void catcher(const int sig)
{
    signalled = sig;
}

main()
{
    struct termios	cooked, raw;
    unsigned char	c;
    unsigned int	i, timeouts;

    for (i = SIGHUP; i <= SIGPOLL; i++)
	(void) signal(i, catcher);

    // Get the state of the tty 
    (void) tcgetattr(0, &cooked);
    // Make a copy we can mess with
    (void) memcpy(&raw, &cooked, sizeof(struct termios));
    // Turn off echoing, linebuffering, and special-character processing,
    // but not the SIGINT or SIGQUIT keys.
    raw.c_lflag &=~ (ICANON | ECHO);
    // Ship the raw control blts
    (void) tcsetattr(0, TCSANOW, &raw);

    (void) printf("Type any key to see the sequence it sends, ^C to quit.\n");
    signalled = 0;
    while (!signalled)
    {
	int		meta;

	read(0, &c, 1);
	if (meta = (c & META))
	    c &=~ META;

	if (c <= ' ')
	    (void) printf("<%s%s>", meta ? "ALT-" : "", lowchars[c]);
	else if (c == 0x3F)
	    (void) printf("<%sDEL>", meta ? "ALT-" : "");
	else if (meta)
	    (void) printf("<ALT-%c>", c);
	else
	    (void) putchar(c);
	(void) fflush(stdout);
    }

    (void) printf("\nBye...\n");
    // Restore the cooked state
    (void) tcsetattr(0, TCSANOW, &cooked);
}

/* showkey.c ends here */