1 /*	$NetBSD: gets_chk.c,v 1.7 2013/10/04 20:49:16 christos Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Christos Zoulas.
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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*LINTLIBRARY*/
33 
34 #include <ssp/ssp.h>
35 #include <stdio.h>
36 #include <string.h>
37 #include <limits.h>
38 #include <stdlib.h>
39 #include <ssp/stdio.h>
40 
41 char *
__gets_chk(char * __restrict str,size_t slen)42 __gets_chk(char * __restrict str, size_t slen)
43 {
44 	char *cp = str;
45 
46         for (;;) {
47                 int c = getchar();
48                 switch (c) {
49                 case EOF:
50                         if (ferror(stdin) || cp == str)
51                                 return NULL;
52                         __PICOLIBC_FALLTHROUGH;
53                 case '\n':
54                         if (slen == 0)
55                                 __chk_fail();
56                         *cp = '\0';
57                         return str;
58                 default:
59                         if (slen == 0)
60                                 __chk_fail();
61                         slen--;
62                         *cp++ = (char)c;
63                 }
64 	}
65 }
66