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      1 /*	$NetBSD: tr.c,v 1.20 2013/08/11 01:54:35 dholland Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. Neither the name of the University nor the names of its contributors
     16  *    may be used to endorse or promote products derived from this software
     17  *    without specific prior written permission.
     18  *
     19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     29  * SUCH DAMAGE.
     30  */
     31 
     32 #include <sys/cdefs.h>
     33 #ifndef lint
     34 __COPYRIGHT("@(#) Copyright (c) 1988, 1993\
     35  The Regents of the University of California.  All rights reserved.");
     36 #endif /* not lint */
     37 
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)tr.c	8.2 (Berkeley) 5/4/95";
     41 #endif
     42 __RCSID("$NetBSD: tr.c,v 1.20 2013/08/11 01:54:35 dholland Exp $");
     43 #endif /* not lint */
     44 
     45 #include <sys/types.h>
     46 
     47 #include <err.h>
     48 #include <stdio.h>
     49 #include <stdlib.h>
     50 #include <string.h>
     51 #include <unistd.h>
     52 
     53 #include "extern.h"
     54 
     55 static int string1[NCHARS], string2[NCHARS];
     56 
     57 static void setup(int *, const char *, int, int);
     58 __dead static void usage(void);
     59 
     60 int
     61 main(int argc, char **argv)
     62 {
     63 	int ch, ch2, lastch;
     64 	int cflag, dflag, sflag, isstring2;
     65 	STR *s1, *s2;
     66 
     67 	cflag = dflag = sflag = 0;
     68 	while ((ch = getopt(argc, argv, "cds")) != -1)
     69 		switch (ch) {
     70 		case 'c':
     71 			cflag = 1;
     72 			break;
     73 		case 'd':
     74 			dflag = 1;
     75 			break;
     76 		case 's':
     77 			sflag = 1;
     78 			break;
     79 		case '?':
     80 		default:
     81 			usage();
     82 		}
     83 	argc -= optind;
     84 	argv += optind;
     85 
     86 	switch(argc) {
     87 	case 0:
     88 	default:
     89 		usage();
     90 		/* NOTREACHED */
     91 	case 1:
     92 		isstring2 = 0;
     93 		break;
     94 	case 2:
     95 		isstring2 = 1;
     96 		break;
     97 	}
     98 
     99 	/*
    100 	 * tr -ds [-c] string1 string2
    101 	 * Delete all characters (or complemented characters) in string1.
    102 	 * Squeeze all characters in string2.
    103 	 */
    104 	if (dflag && sflag) {
    105 		if (!isstring2)
    106 			usage();
    107 
    108 		setup(string1, argv[0], 1, cflag);
    109 		setup(string2, argv[1], 2, 0);
    110 
    111 		for (lastch = OOBCH; (ch = getchar()) != EOF; )
    112 			if (!string1[ch] && (!string2[ch] || lastch != ch)) {
    113 				lastch = ch;
    114 				(void)putchar(ch);
    115 			}
    116 		exit(0);
    117 	}
    118 
    119 	/*
    120 	 * tr -d [-c] string1
    121 	 * Delete all characters (or complemented characters) in string1.
    122 	 */
    123 	if (dflag) {
    124 		if (isstring2)
    125 			usage();
    126 
    127 		setup(string1, argv[0], 1, cflag);
    128 
    129 		while ((ch = getchar()) != EOF)
    130 			if (!string1[ch])
    131 				(void)putchar(ch);
    132 		exit(0);
    133 	}
    134 
    135 	/*
    136 	 * tr -s [-c] string1
    137 	 * Squeeze all characters (or complemented characters) in string1.
    138 	 */
    139 	if (sflag && !isstring2) {
    140 		setup(string1, argv[0], 1, cflag);
    141 
    142 		for (lastch = OOBCH; (ch = getchar()) != EOF;)
    143 			if (!string1[ch] || lastch != ch) {
    144 				lastch = ch;
    145 				(void)putchar(ch);
    146 			}
    147 		exit(0);
    148 	}
    149 
    150 	/*
    151 	 * tr [-cs] string1 string2
    152 	 * Replace all characters (or complemented characters) in string1 with
    153 	 * the character in the same position in string2.  If the -s option is
    154 	 * specified, squeeze all the characters in string2.
    155 	 */
    156 	if (!isstring2)
    157 		usage();
    158 
    159 	/*
    160 	 * The first and second strings need to be matched up. This
    161 	 * means that if we are doing -c, we need to scan the first
    162 	 * string in advance, complement it, and match *that* against
    163 	 * the second string; otherwise we need to scan them together.
    164 	 */
    165 
    166 	if (cflag) {
    167 		/*
    168 		 * Scan string 1 and complement it. After this,
    169 		 * string1[] contains 0 for chars to leave alone and 1
    170 		 * for chars to translate.
    171 		 */
    172 		setup(string1, argv[0], 1, cflag);
    173 		s1 = NULL; /* for safety */
    174 		/* we will use ch to iterate over string1, so start it */
    175 		ch = -1;
    176 	} else {
    177 		/* Create the scanner for string 1. */
    178 		s1 = str_create(1, argv[0]);
    179 		for (ch = 0; ch < NCHARS; ch++) {
    180 			string1[ch] = ch;
    181 		}
    182 	}
    183 	/* Create the scanner for string 2. */
    184 	s2 = str_create(2, argv[1]);
    185 
    186 	/* Read the first char of string 2 first to make sure there is one. */
    187 	if (!next(s2, &ch2))
    188 		errx(1, "empty string2");
    189 
    190 	/*
    191 	 * Loop over the chars from string 1. After this loop string1[]
    192 	 * is a mapping from input to output chars.
    193 	 */
    194 	while (1) {
    195 		if (cflag) {
    196 			/*
    197 			 * Try each character in order. For characters we
    198 			 * skip over because we aren't translating them,
    199 			 * set the translation to the identity.
    200 			 */
    201 			ch++;
    202 			while (ch < NCHARS && string1[ch] == 0) {
    203 				if (string1[ch] == 0) {
    204 					string1[ch] = ch;
    205 				}
    206 				ch++;
    207 			}
    208 			if (ch == NCHARS) {
    209 				break;
    210 			}
    211 		}
    212 		else {
    213 			/* Get the next character from string 1. */
    214 			if (!next(s1, &ch)) {
    215 				break;
    216 			}
    217 		}
    218 
    219 		/* Set the translation to the character from string 2. */
    220 		string1[ch] = ch2;
    221 
    222 		/* Note the characters to squeeze in string2[]. */
    223 		if (sflag) {
    224 			string2[ch2] = 1;
    225 		}
    226 
    227 		/*
    228 		 * Get the next character from string 2. If it runs
    229 		 * out, this will keep returning the last character
    230 		 * over and over again.
    231 		 */
    232 		(void)next(s2, &ch2);
    233 	}
    234 
    235 	/*
    236 	 * Now do it.
    237 	 */
    238 
    239 	if (sflag)
    240 		for (lastch = OOBCH; (ch = getchar()) != EOF;) {
    241 			ch = string1[ch];
    242 			if (!string2[ch] || lastch != ch) {
    243 				lastch = ch;
    244 				(void)putchar(ch);
    245 			}
    246 		}
    247 	else
    248 		while ((ch = getchar()) != EOF)
    249 			(void)putchar(string1[ch]);
    250 
    251 	/* Clean up and exit. */
    252 	if (s1 != NULL) {
    253 		str_destroy(s1);
    254 	}
    255 	str_destroy(s2);
    256 	exit (0);
    257 }
    258 
    259 static void
    260 setup(int *string, const char *arg, int whichstring, int cflag)
    261 {
    262 	int cnt, *p;
    263 	int ch;
    264 	STR *str;
    265 
    266 	str = str_create(whichstring, arg);
    267 	while (next(str, &ch))
    268 		string[ch] = 1;
    269 	if (cflag)
    270 		for (p = string, cnt = NCHARS; cnt--; ++p)
    271 			*p = !*p;
    272 	str_destroy(str);
    273 }
    274 
    275 static void
    276 usage(void)
    277 {
    278 	(void)fprintf(stderr, "usage: tr [-cs] string1 string2\n");
    279 	(void)fprintf(stderr, "       tr [-c] -d string1\n");
    280 	(void)fprintf(stderr, "       tr [-c] -s string1\n");
    281 	(void)fprintf(stderr, "       tr [-c] -ds string1 string2\n");
    282 	exit(1);
    283 }
    284