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
  34 #ifndef lint
  35 static const char copyright[] =
  36 "@(#) Copyright (c) 1980, 1993\n\
  37         The Regents of the University of California.  All rights reserved.\n";
  38 #endif /* not lint */
  39
  40 #ifndef lint
  41 #if 0
  42 static char sccsid[] = "@(#)expand.c    8.1 (Berkeley) 6/9/93";
  43 #endif
  44 #endif /* not lint */
  45 #include <sys/cdefs.h>
  46 __FBSDID("$FreeBSD: src/usr.bin/expand/expand.c,v 1.5.2.6 2002/07/09 10:47:59 tjr Exp $");
  47
  48 #include <ctype.h>
  49 #include <err.h>
  50 #include <locale.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <unistd.h>
  54
  55 /*
  56  * expand - expand tabs to equivalent spaces
  57  */
  58 int     nstops;
  59 int     tabstops[100];
  60
  61 static void getstops(char *);
  62 static void usage(void);
  63
  64 int
  65 main(argc, argv)
  66         int argc;
  67         char *argv[];
  68 {
  69         register int c, column;
  70         register int n;
  71         int rval;
  72
  73         setlocale(LC_CTYPE, "");
  74
  75         /* handle obsolete syntax */
  76         while (argc > 1 && argv[1][0] == '-' &&
  77             isdigit((unsigned char)argv[1][1])) {
  78                 getstops(&argv[1][1]);
  79                 argc--; argv++;
  80         }
  81
  82         while ((c = getopt (argc, argv, "t:")) != -1) {
  83                 switch (c) {
  84                 case 't':
  85                         getstops(optarg);
  86                         break;
  87                 case '?':
  88                 default:
  89                         usage();
  90                         /* NOTREACHED */
  91                 }
  92         }
  93         argc -= optind;
  94         argv += optind;
  95
  96         rval = 0;
  97         do {
  98                 if (argc > 0) {
  99                         if (freopen(argv[0], "r", stdin) == NULL) {
 100                                 warn("%s", argv[0]);
 101                                 rval = 1;
 102                                 argc--, argv++;
 103                                 continue;
 104                         }
 105                         argc--, argv++;
 106                 }
 107                 column = 0;
 108                 while ((c = getchar()) != EOF) {
 109                         switch (c) {
 110                         case '\t':
 111                                 if (nstops == 0) {
 112                                         do {
 113                                                 putchar(' ');
 114                                                 column++;
 115                                         } while (column & 07);
 116                                         continue;
 117                                 }
 118                                 if (nstops == 1) {
 119                                         do {
 120                                                 putchar(' ');
 121                                                 column++;
 122                                         } while (((column - 1) % tabstops[0]) != (tabstops[0] - 1));
 123                                         continue;
 124                                 }
 125                                 for (n = 0; n < nstops; n++)
 126                                         if (tabstops[n] > column)
 127                                                 break;
 128                                 if (n == nstops) {
 129                                         putchar(' ');
 130                                         column++;
 131                                         continue;
 132                                 }
 133                                 while (column < tabstops[n]) {
 134                                         putchar(' ');
 135                                         column++;
 136                                 }
 137                                 continue;
 138
 139                         case '\b':
 140                                 if (column)
 141                                         column--;
 142                                 putchar('\b');
 143                                 continue;
 144
 145                         default:
 146                                 putchar(c);
 147                                 if (isprint(c))
 148                                         column++;
 149                                 continue;
 150
 151                         case '\n':
 152                                 putchar(c);
 153                                 column = 0;
 154                                 continue;
 155                         }
 156                 }
 157         } while (argc > 0);
 158         exit(rval);
 159 }
 160
 161 static void
 162 getstops(cp)
 163         register char *cp;
 164 {
 165         register int i;
 166
 167         nstops = 0;
 168         for (;;) {
 169                 i = 0;
 170                 while (*cp >= '0' && *cp <= '9')
 171                         i = i * 10 + *cp++ - '0';
 172                 if (i <= 0)
 173                         errx(1, "bad tab stop spec");
 174                 if (nstops > 0 && i <= tabstops[nstops-1])
 175                         errx(1, "bad tab stop spec");
 176                 if (nstops == sizeof(tabstops) / sizeof(*tabstops))
 177                         errx(1, "too many tab stops");
 178                 tabstops[nstops++] = i;
 179                 if (*cp == 0)
 180                         break;
 181                 if (*cp != ',' && !isblank((unsigned char)*cp))
 182                         errx(1, "bad tab stop spec");
 183                 cp++;
 184         }
 185 }
 186
 187 static void
 188 usage()
 189 {
 190         (void)fprintf (stderr, "usage: expand [-t tablist] [file ...]\n");
 191         exit(1);
 192 }