/*	$NetBSD: tr.c,v 1.20 2013/08/11 01:54:35 dholland 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 <bsd/sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1988, 1993\
 The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)tr.c	8.2 (Berkeley) 5/4/95";
#endif
__RCSID("$NetBSD: tr.c,v 1.20 2013/08/11 01:54:35 dholland Exp $");
#endif /* not lint */

#include <sys/types.h>

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

#include <bsd/compat.h>

#include "extern.h"

static int string1[NCHARS], string2[NCHARS];

static void setup(int *, const char *, int, int);
__dead static void usage(void);

int main(int argc, char **argv) {
  int ch, ch2, lastch;
  int cflag, dflag, sflag, isstring2;
  STR *s1, *s2;

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

  switch (argc) {
  case 0:
  default:
    usage();
    /* NOTREACHED */
  case 1:
    isstring2 = 0;
    break;
  case 2:
    isstring2 = 1;
    break;
  }

  /*
   * tr -ds [-c] string1 string2
   * Delete all characters (or complemented characters) in string1.
   * Squeeze all characters in string2.
   */
  if (dflag && sflag) {
    if (!isstring2)
      usage();

    setup(string1, argv[0], 1, cflag);
    setup(string2, argv[1], 2, 0);

    for (lastch = OOBCH; (ch = getchar()) != EOF;)
      if (!string1[ch] && (!string2[ch] || lastch != ch)) {
        lastch = ch;
        (void)putchar(ch);
      }
    exit(0);
  }

  /*
   * tr -d [-c] string1
   * Delete all characters (or complemented characters) in string1.
   */
  if (dflag) {
    if (isstring2)
      usage();

    setup(string1, argv[0], 1, cflag);

    while ((ch = getchar()) != EOF)
      if (!string1[ch])
        (void)putchar(ch);
    exit(0);
  }

  /*
   * tr -s [-c] string1
   * Squeeze all characters (or complemented characters) in string1.
   */
  if (sflag && !isstring2) {
    setup(string1, argv[0], 1, cflag);

    for (lastch = OOBCH; (ch = getchar()) != EOF;)
      if (!string1[ch] || lastch != ch) {
        lastch = ch;
        (void)putchar(ch);
      }
    exit(0);
  }

  /*
   * tr [-cs] 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 (!isstring2)
    usage();

  /*
   * The first and second strings need to be matched up. This
   * means that if we are doing -c, we need to scan the first
   * string in advance, complement it, and match *that* against
   * the second string; otherwise we need to scan them together.
   */

  if (cflag) {
    /*
     * Scan string 1 and complement it. After this,
     * string1[] contains 0 for chars to leave alone and 1
     * for chars to translate.
     */
    setup(string1, argv[0], 1, cflag);
    s1 = NULL; /* for safety */
    /* we will use ch to iterate over string1, so start it */
    ch = -1;
  } else {
    /* Create the scanner for string 1. */
    s1 = str_create(1, argv[0]);
    for (ch = 0; ch < NCHARS; ch++) {
      string1[ch] = ch;
    }
  }
  /* Create the scanner for string 2. */
  s2 = str_create(2, argv[1]);

  /* Read the first char of string 2 first to make sure there is one. */
  if (!next(s2, &ch2))
    errx(1, "empty string2");

  /*
   * Loop over the chars from string 1. After this loop string1[]
   * is a mapping from input to output chars.
   */
  while (1) {
    if (cflag) {
      /*
       * Try each character in order. For characters we
       * skip over because we aren't translating them,
       * set the translation to the identity.
       */
      ch++;
      while (ch < NCHARS && string1[ch] == 0) {
        if (string1[ch] == 0) {
          string1[ch] = ch;
        }
        ch++;
      }
      if (ch == NCHARS) {
        break;
      }
    } else {
      /* Get the next character from string 1. */
      if (!next(s1, &ch)) {
        break;
      }
    }

    /* Set the translation to the character from string 2. */
    string1[ch] = ch2;

    /* Note the characters to squeeze in string2[]. */
    if (sflag) {
      string2[ch2] = 1;
    }

    /*
     * Get the next character from string 2. If it runs
     * out, this will keep returning the last character
     * over and over again.
     */
    (void)next(s2, &ch2);
  }

  /*
   * Now do it.
   */

  if (sflag)
    for (lastch = OOBCH; (ch = getchar()) != EOF;) {
      ch = string1[ch];
      if (!string2[ch] || lastch != ch) {
        lastch = ch;
        (void)putchar(ch);
      }
    }
  else
    while ((ch = getchar()) != EOF)
      (void)putchar(string1[ch]);

  /* Clean up and exit. */
  if (s1 != NULL) {
    str_destroy(s1);
  }
  str_destroy(s2);
  exit(0);
}

static void setup(int *string, const char *arg, int whichstring, int cflag) {
  int cnt, *p;
  int ch;
  STR *str;

  str = str_create(whichstring, arg);
  while (next(str, &ch))
    string[ch] = 1;
  if (cflag)
    for (p = string, cnt = NCHARS; cnt--; ++p)
      *p = !*p;
  str_destroy(str);
}

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