1 /* Provide a working getlogin_r for systems which lack it.
2
3 Copyright (C) 2005 Free Software Foundation, Inc.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published by
7 the Free Software Foundation; either version 2, or (at your option)
8 any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU General Public License for more details.
14
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, write to the Free Software Foundation,
17 Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */
18 #include <sys/cdefs.h>
19 __RCSID("$NetBSD: getlogin_r.c,v 1.2 2016/05/17 14:00:09 christos Exp $");
20
21
22 /* written by Paul Eggert and Derek Price */
23
24 #ifdef HAVE_CONFIG_H
25 # include <config.h>
26 #endif
27
28 #include "getlogin_r.h"
29
30 #include <errno.h>
31 #include <string.h>
32
33 #if HAVE_UNISTD_H
34 # include <unistd.h>
35 #endif
36
37 #if !HAVE_DECL_GETLOGIN
38 char *getlogin (void);
39 #endif
40
41 /* See getlogin_r.h for documentation. */
42 int
getlogin_r(char * name,size_t size)43 getlogin_r (char *name, size_t size)
44 {
45 char *n;
46 size_t nlen;
47
48 errno = 0;
49 n = getlogin ();
50
51 /* A system function like getlogin_r is never supposed to set errno
52 to zero, so make sure errno is nonzero here. ENOENT is a
53 reasonable errno value if getlogin returns NULL. */
54 if (!errno)
55 errno = ENOENT;
56
57 if (!n)
58 return errno;
59 nlen = strlen (n);
60 if (size <= nlen)
61 return ERANGE;
62 memcpy (name, n, nlen + 1);
63 return 0;
64 }
65