gets.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1990, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Chris Torek.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#if defined(LIBC_SCCS) && !defined(lint)
36static char sccsid[] = "@(#)gets.c	8.1 (Berkeley) 6/4/93";
37#endif /* LIBC_SCCS and not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD: stable/11/lib/libc/stdio/gets.c 330897 2018-03-14 03:19:51Z eadler $");
40
41#include "namespace.h"
42#include <unistd.h>
43#include <stdio.h>
44#include "un-namespace.h"
45#include "libc_private.h"
46#include "local.h"
47
48__warn_references(gets, "warning: this program uses gets(), which is unsafe.");
49
50char *
51gets(char *buf)
52{
53	int c;
54	char *s, *ret;
55	static int warned;
56	static const char w[] =
57	    "warning: this program uses gets(), which is unsafe.\n";
58
59	FLOCKFILE_CANCELSAFE(stdin);
60	ORIENT(stdin, -1);
61	if (!warned) {
62		(void) _write(STDERR_FILENO, w, sizeof(w) - 1);
63		warned = 1;
64	}
65	for (s = buf; (c = __sgetc(stdin)) != '\n'; ) {
66		if (c == EOF)
67			if (s == buf) {
68				ret = NULL;
69				goto end;
70			} else
71				break;
72		else
73			*s++ = c;
74	}
75	*s = 0;
76	ret = buf;
77end:
78	FUNLOCKFILE_CANCELSAFE();
79	return (ret);
80}
81