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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1980, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)expand.c 8.1 (Berkeley) 6/9/93
  35  * $FreeBSD: src/usr.bin/expand/expand.c,v 1.5.2.6 2002/07/09 10:47:59 tjr Exp $
  36  * $DragonFly: src/usr.bin/expand/expand.c,v 1.4 2005/04/10 20:55:38 drhodus Exp $
  37  */
  38
  39 #include <ctype.h>
  40 #include <err.h>
  41 #include <locale.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <unistd.h>
  45
  46 /*
  47  * expand - expand tabs to equivalent spaces
  48  */
  49 int     nstops;
  50 int     tabstops[100];
  51
  52 static void getstops(char *);
  53 static void usage(void);
  54
  55 int
  56 main(int argc, char **argv)
  57 {
  58         int c, column;
  59         int n;
  60         int rval;
  61
  62         setlocale(LC_CTYPE, "");
  63
  64         /* handle obsolete syntax */
  65         while (argc > 1 && argv[1][0] == '-' &&
  66             isdigit((unsigned char)argv[1][1])) {
  67                 getstops(&argv[1][1]);
  68                 argc--; argv++;
  69         }
  70
  71         while ((c = getopt (argc, argv, "t:")) != -1) {
  72                 switch (c) {
  73                 case 't':
  74                         getstops(optarg);
  75                         break;
  76                 case '?':
  77                 default:
  78                         usage();
  79                         /* NOTREACHED */
  80                 }
  81         }
  82         argc -= optind;
  83         argv += optind;
  84
  85         rval = 0;
  86         do {
  87                 if (argc > 0) {
  88                         if (freopen(argv[0], "r", stdin) == NULL) {
  89                                 warn("%s", argv[0]);
  90                                 rval = 1;
  91                                 argc--, argv++;
  92                                 continue;
  93                         }
  94                         argc--, argv++;
  95                 }
  96                 column = 0;
  97                 while ((c = getchar()) != EOF) {
  98                         switch (c) {
  99                         case '\t':
 100                                 if (nstops == 0) {
 101                                         do {
 102                                                 putchar(' ');
 103                                                 column++;
 104                                         } while (column & 07);
 105                                         continue;
 106                                 }
 107                                 if (nstops == 1) {
 108                                         do {
 109                                                 putchar(' ');
 110                                                 column++;
 111                                         } while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
 112                                         continue;
 113                                 }
 114                                 for (n = 0; n < nstops; n++)
 115                                         if (tabstops[n] > column)
 116                                                 break;
 117                                 if (n == nstops) {
 118                                         putchar(' ');
 119                                         column++;
 120                                         continue;
 121                                 }
 122                                 while (column < tabstops[n]) {
 123                                         putchar(' ');
 124                                         column++;
 125                                 }
 126                                 continue;
 127
 128                         case '\b':
 129                                 if (column)
 130                                         column--;
 131                                 putchar('\b');
 132                                 continue;
 133
 134                         default:
 135                                 putchar(c);
 136                                 if (isprint(c))
 137                                         column++;
 138                                 continue;
 139
 140                         case '\n':
 141                                 putchar(c);
 142                                 column = 0;
 143                                 continue;
 144                         }
 145                 }
 146         } while (argc > 0);
 147         exit(rval);
 148 }
 149
 150 static void
 151 getstops(char *cp)
 152 {
 153         int i;
 154
 155         nstops = 0;
 156         for (;;) {
 157                 i = 0;
 158                 while (*cp >= '0' && *cp <= '9')
 159                         i = i * 10 + *cp++ - '0';
 160                 if (i <= 0)
 161                         errx(1, "bad tab stop spec");
 162                 if (nstops > 0 && i <= tabstops[nstops-1])
 163                         errx(1, "bad tab stop spec");
 164                 if (nstops == sizeof(tabstops) / sizeof(*tabstops))
 165                         errx(1, "too many tab stops");
 166                 tabstops[nstops++] = i;
 167                 if (*cp == 0)
 168                         break;
 169                 if (*cp != ',' && !isblank((unsigned char)*cp))
 170                         errx(1, "bad tab stop spec");
 171                 cp++;
 172         }
 173 }
 174
 175 static void
 176 usage(void)
 177 {
 178         (void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
 179         exit(1);
 180 }