usr/src/usr.bin/vis/foldit.c

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * %sccs.include.redist.c%
 */

#ifndef lint
static char sccsid[] = "@(#)foldit.c    5.1 (Berkeley) %G%";
#endif /* not lint */

foldit(chunk, col, max)
        char *chunk;
{
        register char *cp;

        /*
         * Keep track of column position. Insert hidden newline
         * if this chunk puts us over the limit.
         */
again:
        cp = chunk;
        while (*cp) {
                switch(*cp) {
                case '\n':
                case '\r':
                        col = 0;
                        break;
                case '\t':
                        col = col + 8 &~ 07;
                        break;
                case '\b':
                        col = col ? col - 1 : 0;
                        break;
                default:
                        col++;
                }
                if (col > (max - 2)) {
                        printf("\\\n");
                        col = 0;
                        goto again;
                }
                cp++;
        }
        return (col);
}