gets.c revision 110127 
1/*-
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Chris Torek.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#if defined(LIBC_SCCS) && !defined(lint)
38static char sccsid[] = "@(#)gets.c	8.1 (Berkeley) 6/4/93";
39#endif /* LIBC_SCCS and not lint */
40#include <sys/cdefs.h>
41__FBSDID("$FreeBSD: head/lib/libc/stdio/gets.c 110127 2003-01-30 23:32:53Z tjr $");
42
43#include "namespace.h"
44#include <unistd.h>
45#include <stdio.h>
46#include <sys/cdefs.h>
47#include "un-namespace.h"
48#include "libc_private.h"
49#include "local.h"
50
51__warn_references(gets, "warning: this program uses gets(), which is unsafe.");
52
53char *
54gets(buf)
55	char *buf;
56{
57	int c;
58	char *s;
59	static int warned;
60	static char w[] =
61	    "warning: this program uses gets(), which is unsafe.\n";
62
63	FLOCKFILE(stdin);
64	ORIENT(stdin, -1);
65	if (!warned) {
66		(void) _write(STDERR_FILENO, w, sizeof(w) - 1);
67		warned = 1;
68	}
69	for (s = buf; (c = __sgetc(stdin)) != '\n';)
70		if (c == EOF)
71			if (s == buf) {
72				FUNLOCKFILE(stdin);
73				return (NULL);
74			} else
75				break;
76		else
77			*s++ = c;
78	*s = 0;
79	FUNLOCKFILE(stdin);
80	return (buf);
81}
82