/*      $NetBSD: colrm.c,v 1.9 2011/08/30 21:35:09 joerg Exp $  */

/*-
* Copyright (c) 1991, 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1991, 1993\
The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)colrm.c     8.2 (Berkeley) 5/4/95";
#endif
__RCSID("$NetBSD: colrm.c,v 1.9 2011/08/30 21:35:09 joerg Exp $");
#endif /* not lint */

#include <sys/types.h>

#include <err.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define TAB     8

static void     check(FILE *);
__dead static void      usage(void);

int
main(int argc, char *argv[])
{
       u_long column, start, stop;
       int ch;
       char *p;

       while ((ch = getopt(argc, argv, "")) != -1)
               switch(ch) {
               case '?':
               default:
                       usage();
               }
       argc -= optind;
       argv += optind;

       start = stop = 0;
       switch(argc) {
       case 2:
               stop = strtol(argv[1], &p, 10);
               if (stop <= 0 || *p)
                       errx(1, "illegal column -- %s", argv[1]);
               /* FALLTHROUGH */
       case 1:
               start = strtol(argv[0], &p, 10);
               if (start <= 0 || *p)
                       errx(1, "illegal column -- %s", argv[0]);
               break;
       case 0:
               break;
       default:
               usage();
       }

       if (stop && start > stop)
               err(1, "illegal start and stop columns");

       for (column = 0;;) {
               switch (ch = getchar()) {
               case EOF:
                       check(stdin);
                       break;
               case '\b':
                       if (column)
                               --column;
                       break;
               case '\n':
                       column = 0;
                       break;
               case '\t':
                       column = (column + TAB) & ~(TAB - 1);
                       break;
               default:
                       ++column;
                       break;
               }

               if ((!start || column < start || (stop && column > stop)) &&
                   putchar(ch) == EOF)
                       check(stdout);
       }
}

static void
check(FILE *stream)
{
       if (feof(stream))
               exit(0);
       if (ferror(stream))
               err(1, "%s", stream == stdin ? "stdin" : "stdout");
}

static void
usage(void)
{
       (void)fprintf(stderr, "usage: colrm [start [stop]]\n");
       exit(1);
}