xref: /titanic_50/usr/src/cmd/vi/misc/fold.c (revision f6db9f272f0061301cfaa1c0001b7d636eae31f4)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
/*	  All Rights Reserved  	*/

/*
 * University Copyright- Copyright (c) 1982, 1986, 1988
 * The Regents of the University of California
 * All Rights Reserved
 *
 * University Acknowledgment- Portions of this document are derived from
 * software developed by the University of California, Berkeley, and its
 * contributors.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

#include <stdio.h>
/*
 * fold - fold long lines for finite output devices
 *
 */

int	fold =  80;

void putch(int c);

int
main(int argc, char *argv[])
{
	int c;
	FILE *f;
	char obuf[BUFSIZ];

	argc--, argv++;
	setbuf(stdout, obuf);
	if (argc > 0 && argv[0][0] == '-') {
		fold = 0;
		argv[0]++;
		while (*argv[0] >= '0' && *argv[0] <= '9')
			fold *= 10, fold += *argv[0]++ - '0';
		if (*argv[0]) {
			printf("Bad number for fold\n");
			exit(1);
		}
		argc--, argv++;
	}
	do {
		if (argc > 0) {
			if (freopen(argv[0], "r", stdin) == NULL) {
				perror(argv[0]);
				exit(1);
			}
			argc--, argv++;
		}
		for (;;) {
			c = getc(stdin);
			if (c == -1)
				break;
			putch(c);
		}
	} while (argc > 0);
	return (0);
}

int	col;

void
putch(int c)
{
	int ncol;

	switch (c) {
		case '\n':
			ncol = 0;
			break;
		case '\t':
			ncol = (col + 8) &~ 7;
			break;
		case '\b':
			ncol = col ? col - 1 : 0;
			break;
		case '\r':
			ncol = 0;
			break;
		default:
			ncol = col + 1;
	}
	if (ncol > fold)
		putchar('\n'), col = 0;
	putchar(c);
	switch (c) {
		case '\n':
			col = 0;
			break;
		case '\t':
			col += 8;
			col &= ~7;
			break;
		case '\b':
			if (col)
				col--;
			break;
		case '\r':
			col = 0;
			break;
		default:
			col++;
			break;
	}
}