#include <stdio.h>

/**
 * CTLSEQ -- control sequence cat-like program
 * Copyright (C) 2007  Matous Jan Fialka
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see
 * <http://www.gnu.org/licenses/>.
 */

void eot(void)
{
	exit(0);
}

/**
 *	CHAR    ASCII   HEX     MEANING
 *
 *	[@]     NUL     00
 *	[A]     SOH     01
 *	[B]     STX     02
 *	[C]     ETX     03
 *	[D]     EOT     04      end of transmission (passive)
 *	[E]     ENQ     05
 *	[F]     ACK     06
 *	[G]     BEL     07
 *	[H]     BS      08      back space
 *	[I]     HT      09
 *	[J]     LF      0a
 *	[K]     VT      0b
 *	[L]     FF      0c
 *	[M]     CR      0d
 *	[N]     SO      0e
 *	[O]     SI      0f
 *	[P]     DLE     10
 *	[Q]     DC1     11
 *	[R]     DC2     12
 *	[S]     DC3     13
 *	[T]     DC4     14
 *	[U]     NAK     15
 *	[V]     SYN     16
 *	[W]     ETB     17
 *	[X]     CAN     18
 *	[Y]     EM      19
 *	[Z]     SUB     1a
 *	[\[]    ESC     1b
 *	[\\]    FS      1c
 *	[\]]    GS      1d
 *	[\^]    RS      1e
 *	[\_]    US      1f
 *	[\?]    DEL     7f      delete
 */

int mk_cs(int c)
{
	if (c >= 0x40 && c <= 0x5f)
		return (c - 0x40);
	if (c == 0x3f)
		return (0x7f);
	return (c);
}

/**
 *	CHAR    ASCII   HEX     MEANING
 *
 *	[0]	NUL	00
 *	[q]     EOT     04      end of transmission (active)
 *	[a]     BEL     07
 *	[b]     BS      08      back space
 *	[t]     HT      09
 *	[n]     LF      0a
 *	[v]     VT      0b
 *	[f]     FF      0c
 *	[r]     CR      0d
 *	[e]     ESC     1b
 *	[d]     DEL     7f      delete
 */

int mk_ic(int c)
{
	if (c == 0x30)
		return (0x00);
	if (c == 0x71)
		eot();
	if (c == 0x61)
		return (0x07);
	if (c == 0x62)
		return (0x08);
	if (c == 0x74)
		return (0x09);
	if (c == 0x6e)
		return (0x0a);
	if (c == 0x76)
		return (0x0b);
	if (c == 0x66)
		return (0x0c);
	if (c == 0x72)
		return (0x0d);
	if (c == 0x65)
		return (0x1b);
	if (c == 0x64)
		return (0x1f);
	return (c);
}

int is_qc(int c)
{
	return (c == 0x5c);
}

int is_csc(int c)
{
	return (c == 0x5e);
}

int main(void)
{
	int c;

	while ((c = fgetc(stdin)) != EOF) {
		if (is_csc(c)) {
			if ((c = fgetc(stdin)) != EOF) {
				fputc(mk_cs(c), stdout);
				continue;
			}
			break;
		}
		if (is_qc(c)) {
			if ((c = fgetc(stdin)) != EOF) {
				fputc(mk_ic(c), stdout);
				continue;
			}
			break;
		}
		fputc(c, stdout);
	}
	eot();
}