/* $Id$
 * vis functions - visually encode characters
 * Originally from OpenBSD
 */

/*-
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <limits.h>
#include <ctype.h>
/*
 * to select alternate encoding format
 */
#define VIS_OCTAL         0x01        /* use octal \ddd format */
#define VIS_CSTYLE        0x02        /* use \[nrft0..] where appropriate */
/*
 * to alter set of characters encoded (default is to encode all
 * non-graphic except space, tab, and newline).
 */
#define VIS_SP            0x04        /* also encode space */
#define VIS_TAB           0x08        /* also encode tab */
#define VIS_NL            0x10        /* also encode newline */
#define VIS_WHITE         (VIS_SP | VIS_TAB | VIS_NL)
#define VIS_SAFE          0x20        /* only encode "unsafe" characters */

#define VIS_NOSLASH       0x40        /* inhibit printing '\' */

/*
 * unvis return codes
 */
#define UNVIS_VALID     1        /* character valid */
#define UNVIS_VALIDPUSH 2        /* character valid, push back passed char */
#define UNVIS_NOCHAR    3        /* valid sequence, no character produced */
#define UNVIS_SYNBAD   -1        /* unrecognized escape sequence */
#define UNVIS_ERROR    -2        /* decoder in unknown state (unrecoverable) */

/*
 * unvis flags
 */
#define UNVIS_END       1        /* no more characters */

#define isoctal(c)        (((u_char)(c)) >= '0' && ((u_char)(c)) <= '7')
#define isvisible(c)    (((u_int)(c) <= UCHAR_MAX && isascii((u_char)(c)) && \
                                isgraph((u_char)(c))) ||                     \
                                ((flag & VIS_SP) == 0 && (c) == ' ') ||      \
                                ((flag & VIS_TAB) == 0 && (c) == '\t') ||    \
                                ((flag & VIS_NL) == 0 && (c) == '\n') ||     \
                                ((flag & VIS_SAFE) &&                        \
                                ((c) == '\b' || (c) == '\007' || (c) == '\r')))

/*
 * decode driven by state machine
 */
#define S_GROUND        0        /* haven't seen escape char */
#define S_START         1        /* start decoding special sequence */
#define S_META          2        /* metachar started (M) */
#define S_META1         3        /* metachar more, regular char (-) */
#define S_CTRL          4        /* control char started (^) */
#define S_OCTAL2        5        /* octal digit 2 */
#define S_OCTAL3        6        /* octal digit 3 */

char    *vis(char *, int, int, int);
int     strvis(char *, const char *, int);
int     strnvis(char *, const char *, size_t, int);
int     strvisx(char *, const char *, size_t, int);
int     strunvis(char *, const char *);
int     unvis(char *, char, int *, int);