usr.bin/colrm/colrm.c

   1 /*-
   2  * Copyright (c) 1991, 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  * $FreeBSD: head/usr.bin/colrm/colrm.c 216370 2010-12-11 08:32:16Z joel $
  30  *
  31  * @(#) Copyright (c) 1991, 1993 The Regents of the University of California.  All rights reserved.
  32  * @(#)colrm.c  8.2 (Berkeley) 5/4/95
  33  */
  34
  35 #include <sys/types.h>
  36 #include <err.h>
  37 #include <errno.h>
  38 #include <limits.h>
  39 #include <locale.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <string.h>
  43 #include <unistd.h>
  44 #include <wchar.h>
  45
  46 #define TAB     8
  47
  48 void check(FILE *);
  49 static void usage(void);
  50
  51 int
  52 main(int argc, char *argv[])
  53 {
  54         u_long column, start, stop;
  55         int ch, width;
  56         char *p;
  57
  58         setlocale(LC_ALL, "");
  59
  60         while ((ch = getopt(argc, argv, "")) != -1)
  61                 switch(ch) {
  62                 case '?':
  63                 default:
  64                         usage();
  65                 }
  66         argc -= optind;
  67         argv += optind;
  68
  69         start = stop = 0;
  70         switch(argc) {
  71         case 2:
  72                 stop = strtol(argv[1], &p, 10);
  73                 if (stop <= 0 || *p)
  74                         errx(1, "illegal column -- %s", argv[1]);
  75                 /* FALLTHROUGH */
  76         case 1:
  77                 start = strtol(argv[0], &p, 10);
  78                 if (start <= 0 || *p)
  79                         errx(1, "illegal column -- %s", argv[0]);
  80                 break;
  81         case 0:
  82                 break;
  83         default:
  84                 usage();
  85         }
  86
  87         if (stop && start > stop)
  88                 errx(1, "illegal start and stop columns");
  89
  90         for (column = 0;;) {
  91                 switch (ch = getwchar()) {
  92                 case WEOF:
  93                         check(stdin);
  94                         break;
  95                 case '\b':
  96                         if (column)
  97                                 --column;
  98                         break;
  99                 case '\n':
 100                         column = 0;
 101                         break;
 102                 case '\t':
 103                         column = (column + TAB) & ~(TAB - 1);
 104                         break;
 105                 default:
 106                         if ((width = wcwidth(ch)) > 0)
 107                                 column += width;
 108                         break;
 109                 }
 110
 111                 if ((!start || column < start || (stop && column > stop)) &&
 112                     putwchar(ch) == WEOF)
 113                         check(stdout);
 114         }
 115 }
 116
 117 void
 118 check(FILE *stream)
 119 {
 120         if (feof(stream))
 121                 exit(0);
 122         if (ferror(stream))
 123                 err(1, "%s", stream == stdin ? "stdin" : "stdout");
 124 }
 125
 126 void
 127 usage(void)
 128 {
 129         (void)fprintf(stderr, "usage: colrm [start [stop]]\n");
 130         exit(1);
 131 }
 132