usr.bin/unexpand/unexpand.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  * @(#)unexpand.c       8.1 (Berkeley) 6/6/93
  35  * $FreeBSD: src/usr.bin/unexpand/unexpand.c,v 1.5.2.3 2002/10/11 11:33:23 tjr Exp $
  36  * $DragonFly: src/usr.bin/unexpand/unexpand.c,v 1.3 2003/10/04 20:36:54 hmp Exp $
  37  */
  38
  39 /*
  40  * unexpand - put tabs into a file replacing blanks
  41  */
  42 #include <ctype.h>
  43 #include <err.h>
  44 #include <limits.h>
  45 #include <locale.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50
  51 int     all;
  52 int     nstops;
  53 int     tabstops[100];
  54
  55 static void getstops(const char *);
  56 static void usage(void);
  57 static void tabify(void);
  58
  59 int
  60 main(int argc, char **argv)
  61 {
  62         int ch, failed;
  63         char *filename;
  64
  65         setlocale(LC_CTYPE, "");
  66
  67         nstops = 1;
  68         tabstops[0] = 8;
  69         while ((ch = getopt(argc, argv, "at:")) != -1) {
  70                 switch (ch) {
  71                 case 'a':       /* Un-expand all spaces, not just leading. */
  72                         all = 1;
  73                         break;
  74                 case 't':       /* Specify tab list, implies -a. */
  75                         getstops(optarg);
  76                         all = 1;
  77                         break;
  78                 default:
  79                         usage();
  80                         /*NOTREACHED*/
  81                 }
  82         }
  83         argc -= optind;
  84         argv += optind;
  85
  86         failed = 0;
  87         if (argc == 0)
  88                 tabify();
  89         else {
  90                 while ((filename = *argv++) != NULL) {
  91                         if (freopen(filename, "r", stdin) == NULL) {
  92                                 warn("%s", filename);
  93                                 failed++;
  94                         } else
  95                                 tabify();
  96                 }
  97         }
  98         exit(failed != 0);
  99 }
 100
 101 static void
 102 usage(void)
 103 {
 104         fprintf(stderr, "usage: unexpand [-a] [-t tablist] [file ...]\n");
 105         exit(1);
 106 }
 107
 108 static void
 109 tabify(void)
 110 {
 111         int ch, dcol, doneline, limit, n, ocol;
 112
 113         limit = nstops == 1 ? INT_MAX : tabstops[nstops - 1] - 1;
 114
 115         doneline = ocol = dcol = 0;
 116         while ((ch = getchar()) != EOF) {
 117                 if (ch == ' ' && !doneline) {
 118                         if (++dcol >= limit)
 119                                 doneline = 1;
 120                         continue;
 121                 } else if (ch == '\t') {
 122                         if (nstops == 1) {
 123                                 dcol = (1 + dcol / tabstops[0]) *
 124                                     tabstops[0];
 125                                 continue;
 126                         } else {
 127                                 for (n = 0; tabstops[n] - 1 < dcol &&
 128                                     n < nstops; n++)
 129                                         ;
 130                                 if (n < nstops - 1 && tabstops[n] - 1 < limit) {
 131                                         dcol = tabstops[n];
 132                                         continue;
 133                                 }
 134                                 doneline = 1;
 135                         }
 136                 }
 137
 138                 /* Output maximal number of tabs. */
 139                 if (nstops == 1) {
 140                         while (((ocol + tabstops[0]) / tabstops[0])
 141                             <= (dcol / tabstops[0])) {
 142                                 if (dcol - ocol < 2)
 143                                         break;
 144                                 putchar('\t');
 145                                 ocol = (1 + ocol / tabstops[0]) *
 146                                     tabstops[0];
 147                         }
 148                 } else {
 149                         for (n = 0; tabstops[n] - 1 < ocol && n < nstops; n++)
 150                                 ;
 151                         while (ocol < dcol && n < nstops && ocol < limit) {
 152                                 putchar('\t');
 153                                 ocol = tabstops[n++];
 154                         }
 155                 }
 156
 157                 /* Then spaces. */
 158                 while (ocol < dcol && ocol < limit) {
 159                         putchar(' ');
 160                         ocol++;
 161                 }
 162
 163                 if (ch == '\b') {
 164                         putchar('\b');
 165                         if (ocol > 0)
 166                                 ocol--, dcol--;
 167                 } else if (ch == '\n') {
 168                         putchar('\n');
 169                         doneline = ocol = dcol = 0;
 170                         continue;
 171                 } else if (ch != ' ' || dcol > limit) {
 172                         putchar(ch);
 173                         if (isprint(ch))
 174                                 ocol++, dcol++;
 175                 }
 176
 177                 /*
 178                  * Only processing leading blanks or we've gone past the
 179                  * last tab stop. Emit remainder of this line unchanged.
 180                  */
 181                 if (!all || dcol >= limit) {
 182                         while ((ch = getchar()) != '\n' && ch != EOF)
 183                                 putchar(ch);
 184                         if (ch == '\n')
 185                                 putchar('\n');
 186                         doneline = ocol = dcol = 0;
 187                 }
 188         }
 189 }
 190
 191 static void
 192 getstops(const char *cp)
 193 {
 194         int i;
 195
 196         nstops = 0;
 197         for (;;) {
 198                 i = 0;
 199                 while (*cp >= '0' && *cp <= '9')
 200                         i = i * 10 + *cp++ - '0';
 201                 if (i <= 0)
 202                         errx(1, "bad tab stop spec");
 203                 if (nstops > 0 && i <= tabstops[nstops-1])
 204                         errx(1, "bad tab stop spec");
 205                 if (nstops == sizeof(tabstops) / sizeof(*tabstops))
 206                         errx(1, "too many tab stops");
 207                 tabstops[nstops++] = i;
 208                 if (*cp == 0)
 209                         break;
 210                 if (*cp != ',' && !isblank((unsigned char)*cp))
 211                         errx(1, "bad tab stop spec");
 212                 cp++;
 213         }
 214 }