vi/misc/fold.c

/*
 * 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;
    }
}