usr.bin/tr/tr.c

   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 }