usr/src/boot/lib/libstand/gets.c

/*	$NetBSD: gets.c,v 1.6 1995/10/11 21:16:57 pk Exp $	*/

/*
 * Copyright (c) 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.
 * 4. 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.
 *
 *	@(#)gets.c	8.1 (Berkeley) 6/11/93
 */

#include <sys/cdefs.h>

#include "stand.h"

/* gets() with constrained input length */

void
ngets(char *buf, int n)
{
	int c;
	char *lp;

	for (lp = buf; ; ) {
		c = getchar();
		if (c == -1)
			break;
		switch (c & 0177) {
		case '\n':
		case '\r':
			*lp = '\0';
			putchar('\n');
			return;
		case '\b':
		case '\177':
			if (lp > buf) {
				lp--;
				putchar('\b');
				putchar(' ');
				putchar('\b');
			}
			break;
		case 'r' & 037: {
			char *p;

			putchar('\n');
			for (p = buf; p < lp; ++p)
				putchar(*p);
			break;
		}
		case 'u' & 037:
		case 'w' & 037:
			lp = buf;
			putchar('\n');
			break;
		default:
			if ((n < 1) || ((lp - buf) < n - 1)) {
				*lp++ = c;
				putchar(c);
			}
		}
	}
	/*NOTREACHED*/
}

int
fgetstr(char *buf, int size, int fd)
{
	char	c;
	int	err, len;

	size--;	/* leave space for terminator */
	len = 0;
	while (size != 0) {
		err = read(fd, &c, sizeof (c));
		if (err < 0)		/* read error */
			return (-1);
		if (err == 0) {		/* EOF */
			if (len == 0)
				return (-1);	/* nothing to read */
			break;
		}
		if ((c == '\r') ||	/* line terminators */
		    (c == '\n'))
			break;
		*buf++ = c;		/* keep char */
		size--;
		len++;
	}
	*buf = 0;
	return (len);
}