/*      $OpenBSD: tr.c,v 1.22 2022/12/04 23:50:49 cheloha Exp $ */
/*      $NetBSD: tr.c,v 1.5 1995/08/31 22:13:48 jtc Exp $       */

/*
 * Copyright (c) 1988, 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/types.h>

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

#include "extern.h"

int delete[NCHARS], squeeze[NCHARS];
int translate[NCHARS] = {
        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,         /* ASCII */
        0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f,
        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
        0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
        0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
        0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
        0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47,
        0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
        0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57,
        0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
        0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
        0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77,
        0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
        0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
        0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
        0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
        0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
        0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
        0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
        0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
        0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
        0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
        0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
        0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
        0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
        0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
        0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff,
};

STR s1 = { STRING1, NORMAL, 0, OOBCH, { 0, OOBCH }, NULL, NULL };
STR s2 = { STRING2, NORMAL, 0, OOBCH, { 0, OOBCH }, NULL, NULL };

static void setup(int *, char *, STR *, int);
static void usage(void);

int
main(int argc, char *argv[])
{
        int ch, cnt, lastch, *p;
        int cflag, dflag, sflag;

        if (pledge("stdio", NULL) == -1)
                err(1, "pledge");

        cflag = dflag = sflag = 0;
        while ((ch = getopt(argc, argv, "Ccds")) != -1)
                switch(ch) {
                case 'C':
                case 'c':
                        cflag = 1;
                        break;
                case 'd':
                        dflag = 1;
                        break;
                case 's':
                        sflag = 1;
                        break;
                default:
                        usage();
                }
        argc -= optind;
        argv += optind;

        if (argc < 1 || argc > 2)
                usage();

        /*
         * tr -ds [-Cc] string1 string2
         * Delete all characters (or complemented characters) in string1.
         * Squeeze all characters in string2.
         */
        if (dflag && sflag) {
                if (argc != 2)
                        usage();

                setup(delete, argv[0], &s1, cflag);
                setup(squeeze, argv[1], &s2, 0);

                for (lastch = OOBCH; (ch = getchar()) != EOF;)
                        if (!delete[ch] && (!squeeze[ch] || lastch != ch)) {
                                lastch = ch;
                                (void)putchar(ch);
                        }
                exit(0);
        }

        /*
         * tr -d [-Cc] string1
         * Delete all characters (or complemented characters) in string1.
         */
        if (dflag) {
                if (argc != 1)
                        usage();

                setup(delete, argv[0], &s1, cflag);

                while ((ch = getchar()) != EOF)
                        if (!delete[ch])
                                (void)putchar(ch);
                exit(0);
        }

        /*
         * tr -s [-Cc] string1
         * Squeeze all characters (or complemented characters) in string1.
         */
        if (sflag && argc == 1) {
                setup(squeeze, argv[0], &s1, cflag);

                for (lastch = OOBCH; (ch = getchar()) != EOF;)
                        if (!squeeze[ch] || lastch != ch) {
                                lastch = ch;
                                (void)putchar(ch);
                        }
                exit(0);
        }

        /*
         * tr [-Ccs] string1 string2
         * Replace all characters (or complemented characters) in string1 with
         * the character in the same position in string2.  If the -s option is
         * specified, squeeze all the characters in string2.
         */
        if (argc != 2)
                usage();

        s1.str = (unsigned char *)argv[0];
        s2.str = (unsigned char *)argv[1];

        if (cflag)
                for (cnt = NCHARS, p = translate; cnt--;)
                        *p++ = OOBCH;

        if (!next(&s2))
                errx(1, "empty string2");

        /* If string2 runs out of characters, use the last one specified. */
        ch = s2.lastch;
        if (sflag)
                while (next(&s1)) {
                        translate[s1.lastch] = ch = s2.lastch;
                        squeeze[ch] = 1;
                        (void)next(&s2);
                }
        else
                while (next(&s1)) {
                        translate[s1.lastch] = ch = s2.lastch;
                        (void)next(&s2);
                }

        if (cflag)
                for (cnt = 0, p = translate; cnt < NCHARS; ++p, ++cnt)
                        *p = *p == OOBCH ? ch : cnt;

        if (sflag)
                for (lastch = OOBCH; (ch = getchar()) != EOF;) {
                        ch = translate[ch];
                        if (!squeeze[ch] || lastch != ch) {
                                lastch = ch;
                                (void)putchar(ch);
                        }
                }
        else
                while ((ch = getchar()) != EOF)
                        (void)putchar(translate[ch]);
        exit (0);
}

static void
setup(int *table, char *arg, STR *str, int cflag)
{
        int cnt, *p;

        str->str = (unsigned char *)arg;
        bzero(table, NCHARS * sizeof(int));
        while (next(str))
                table[str->lastch] = 1;
        if (cflag)
                for (p = table, cnt = NCHARS; cnt--; ++p)
                        *p = !*p;
}

static void
usage(void)
{
        fprintf(stderr,
            "usage: tr [-Ccs] string1 string2\n"
            "       tr [-Cc] -d string1\n"
            "       tr [-Cc] -s string1\n"
            "       tr [-Cc] -ds string1 string2\n");
        exit(1);
}