xref: /dflybsd-src/stand/lib/gets.c (revision 479ab7f0492f2a51b48e8537e4f1dc686fc6014b)

/*	$NetBSD: gets.c,v 1.6 1995/10/11 21:16:57 pk Exp $	*/
/* $DragonFly: src/lib/libstand/gets.c,v 1.2 2004/10/25 19:38:45 drhodus 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.
 * 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.
 *
 *	@(#)gets.c	8.1 (Berkeley) 6/11/93
 */

#include "stand.h"

/* gets() with constrained input length */

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

    for (lp = buf;;)
	switch (c = getchar() & 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)) {
		*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);
}

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

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