usr.bin/expand/expand.c

   1 /*
   2  * Copyright (c) 1980, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * @(#) Copyright (c) 1980, 1993 The Regents of the University of California.  All rights reserved.
  30  * @(#)expand.c 8.1 (Berkeley) 6/9/93
  31  * $FreeBSD: src/usr.bin/expand/expand.c,v 1.5.2.6 2002/07/09 10:47:59 tjr Exp $
  32  * $DragonFly: src/usr.bin/expand/expand.c,v 1.4 2005/04/10 20:55:38 drhodus Exp $
  33  */
  34
  35 #include <ctype.h>
  36 #include <err.h>
  37 #include <locale.h>
  38 #include <stdio.h>
  39 #include <stdlib.h>
  40 #include <unistd.h>
  41
  42 /*
  43  * expand - expand tabs to equivalent spaces
  44  */
  45 int     nstops;
  46 int     tabstops[100];
  47
  48 static void getstops(char *);
  49 static void usage(void);
  50
  51 int
  52 main(int argc, char **argv)
  53 {
  54         int c, column;
  55         int n;
  56         int rval;
  57
  58         setlocale(LC_CTYPE, "");
  59
  60         /* handle obsolete syntax */
  61         while (argc > 1 && argv[1][0] == '-' &&
  62             isdigit((unsigned char)argv[1][1])) {
  63                 getstops(&argv[1][1]);
  64                 argc--; argv++;
  65         }
  66
  67         while ((c = getopt (argc, argv, "t:")) != -1) {
  68                 switch (c) {
  69                 case 't':
  70                         getstops(optarg);
  71                         break;
  72                 case '?':
  73                 default:
  74                         usage();
  75                         /* NOTREACHED */
  76                 }
  77         }
  78         argc -= optind;
  79         argv += optind;
  80
  81         rval = 0;
  82         do {
  83                 if (argc > 0) {
  84                         if (freopen(argv[0], "r", stdin) == NULL) {
  85                                 warn("%s", argv[0]);
  86                                 rval = 1;
  87                                 argc--, argv++;
  88                                 continue;
  89                         }
  90                         argc--, argv++;
  91                 }
  92                 column = 0;
  93                 while ((c = getchar()) != EOF) {
  94                         switch (c) {
  95                         case '\t':
  96                                 if (nstops == 0) {
  97                                         do {
  98                                                 putchar(' ');
  99                                                 column++;
 100                                         } while (column & 07);
 101                                         continue;
 102                                 }
 103                                 if (nstops == 1) {
 104                                         do {
 105                                                 putchar(' ');
 106                                                 column++;
 107                                         } while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
 108                                         continue;
 109                                 }
 110                                 for (n = 0; n < nstops; n++)
 111                                         if (tabstops[n] > column)
 112                                                 break;
 113                                 if (n == nstops) {
 114                                         putchar(' ');
 115                                         column++;
 116                                         continue;
 117                                 }
 118                                 while (column < tabstops[n]) {
 119                                         putchar(' ');
 120                                         column++;
 121                                 }
 122                                 continue;
 123
 124                         case '\b':
 125                                 if (column)
 126                                         column--;
 127                                 putchar('\b');
 128                                 continue;
 129
 130                         default:
 131                                 putchar(c);
 132                                 if (isprint(c))
 133                                         column++;
 134                                 continue;
 135
 136                         case '\n':
 137                                 putchar(c);
 138                                 column = 0;
 139                                 continue;
 140                         }
 141                 }
 142         } while (argc > 0);
 143         exit(rval);
 144 }
 145
 146 static void
 147 getstops(char *cp)
 148 {
 149         int i;
 150
 151         nstops = 0;
 152         for (;;) {
 153                 i = 0;
 154                 while (*cp >= '0' && *cp <= '9')
 155                         i = i * 10 + *cp++ - '0';
 156                 if (i <= 0)
 157                         errx(1, "bad tab stop spec");
 158                 if (nstops > 0 && i <= tabstops[nstops-1])
 159                         errx(1, "bad tab stop spec");
 160                 if (nstops == sizeof(tabstops) / sizeof(*tabstops))
 161                         errx(1, "too many tab stops");
 162                 tabstops[nstops++] = i;
 163                 if (*cp == 0)
 164                         break;
 165                 if (*cp != ',' && !isblank((unsigned char)*cp))
 166                         errx(1, "bad tab stop spec");
 167                 cp++;
 168         }
 169 }
 170
 171 static void
 172 usage(void)
 173 {
 174         (void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
 175         exit(1);
 176 }