usr.bin/colrm/colrm.c

   1 /*      $NetBSD: colrm.c,v 1.9 2011/08/30 21:35:09 joerg Exp $  */
   2
   3 /*-
   4  * Copyright (c) 1991, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 __COPYRIGHT("@(#) Copyright (c) 1991, 1993\
  35  The Regents of the University of California.  All rights reserved.");
  36 #endif /* not lint */
  37
  38 #ifndef lint
  39 #if 0
  40 static char sccsid[] = "@(#)colrm.c     8.2 (Berkeley) 5/4/95";
  41 #endif
  42 __RCSID("$NetBSD: colrm.c,v 1.9 2011/08/30 21:35:09 joerg Exp $");
  43 #endif /* not lint */
  44
  45 #include <sys/types.h>
  46
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <limits.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54
  55 #define TAB     8
  56
  57 static void     check(FILE *);
  58 __dead static void      usage(void);
  59
  60 int
  61 main(int argc, char *argv[])
  62 {
  63         u_long column, start, stop;
  64         int ch;
  65         char *p;
  66
  67         while ((ch = getopt(argc, argv, "")) != -1)
  68                 switch(ch) {
  69                 case '?':
  70                 default:
  71                         usage();
  72                 }
  73         argc -= optind;
  74         argv += optind;
  75
  76         start = stop = 0;
  77         switch(argc) {
  78         case 2:
  79                 stop = strtol(argv[1], &p, 10);
  80                 if (stop <= 0 || *p)
  81                         errx(1, "illegal column -- %s", argv[1]);
  82                 /* FALLTHROUGH */
  83         case 1:
  84                 start = strtol(argv[0], &p, 10);
  85                 if (start <= 0 || *p)
  86                         errx(1, "illegal column -- %s", argv[0]);
  87                 break;
  88         case 0:
  89                 break;
  90         default:
  91                 usage();
  92         }
  93
  94         if (stop && start > stop)
  95                 err(1, "illegal start and stop columns");
  96
  97         for (column = 0;;) {
  98                 switch (ch = getchar()) {
  99                 case EOF:
 100                         check(stdin);
 101                         break;
 102                 case '\b':
 103                         if (column)
 104                                 --column;
 105                         break;
 106                 case '\n':
 107                         column = 0;
 108                         break;
 109                 case '\t':
 110                         column = (column + TAB) & ~(TAB - 1);
 111                         break;
 112                 default:
 113                         ++column;
 114                         break;
 115                 }
 116
 117                 if ((!start || column < start || (stop && column > stop)) &&
 118                     putchar(ch) == EOF)
 119                         check(stdout);
 120         }
 121 }
 122
 123 static void
 124 check(FILE *stream)
 125 {
 126         if (feof(stream))
 127                 exit(0);
 128         if (ferror(stream))
 129                 err(1, "%s", stream == stdin ? "stdin" : "stdout");
 130 }
 131
 132 static void
 133 usage(void)
 134 {
 135         (void)fprintf(stderr, "usage: colrm [start [stop]]\n");
 136         exit(1);
 137 }