/*      $NetBSD: unvis.c,v 1.13 2010/11/27 19:46:25 christos Exp $      */

/*-
 * 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. 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/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1989, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)unvis.c     8.1 (Berkeley) 6/6/93";
#endif
__RCSID("$NetBSD: unvis.c,v 1.13 2010/11/27 19:46:25 christos Exp $");
#endif /* not lint */

#include <err.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <vis.h>

static void process(FILE *, const char *, int);

int
main(int argc, char *argv[])
{
        FILE *fp;
        int ch, eflags = 0;

        setprogname(argv[0]);
        while ((ch = getopt(argc, argv, "eHhm")) != -1)
                switch((char)ch) {
                case 'e':
                        eflags |= VIS_NOESCAPE;
                        break;
                case 'H':
                        eflags |= VIS_HTTP1866;
                        break;
                case 'h':
                        eflags |= VIS_HTTP1808;
                        break;
                case 'm':
                        eflags |= VIS_MIMESTYLE;
                        break;
                case '?':
                default:
                        (void)fprintf(stderr,
                            "Usage: %s [-e] [-Hh | -m] [file...]\n",
                            getprogname());
                        return EXIT_FAILURE;
                }
        argc -= optind;
        argv += optind;

        switch (eflags & (VIS_HTTP1808|VIS_HTTP1866|VIS_MIMESTYLE)) {
        case VIS_HTTP1808|VIS_MIMESTYLE:
        case VIS_HTTP1866|VIS_MIMESTYLE:
        case VIS_HTTP1808|VIS_HTTP1866|VIS_MIMESTYLE:
                errx(EXIT_FAILURE, "Can't mix -m with -h and/or -H");
                /*NOTREACHED*/
        default:
                break;
        }

        if (*argv)
                while (*argv) {
                        if ((fp = fopen(*argv, "r")) != NULL)
                                process(fp, *argv, eflags);
                        else
                                warn("%s", *argv);
                        argv++;
                }
        else
                process(stdin, "<stdin>", eflags);
        return EXIT_SUCCESS;
}

static void
process(FILE *fp, const char *filename, int eflags)
{
        int offset = 0, c, ret;
        int state = 0;
        char outc;

        while ((c = getc(fp)) != EOF) {
                offset++;
        again:
                switch(ret = unvis(&outc, (char)c, &state, eflags)) {
                case UNVIS_VALID:
                        (void)putchar(outc);
                        break;
                case UNVIS_VALIDPUSH:
                        (void)putchar(outc);
                        goto again;
                case UNVIS_SYNBAD:
                        warnx("%s: offset: %d: can't decode", filename, offset);
                        state = 0;
                        break;
                case 0:
                case UNVIS_NOCHAR:
                        break;
                default:
                        errx(1, "bad return value (%d), can't happen", ret);
                        /* NOTREACHED */
                }
        }
        if (unvis(&outc, (char)0, &state, eflags | UNVIS_END) == UNVIS_VALID)
                (void)putchar(outc);
}