1 /* Provide a working getlogin_r for systems which lack it.
3 Copyright (C) 2005-2007, 2010-2013 Free Software Foundation, Inc.
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)
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.
15 You should have received a copy of the GNU General Public License
16 along with this program; if not, see <http://www.gnu.org/licenses/>. */
18 /* Written by Paul Eggert, Derek Price, and Bruno Haible. */
28 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
29 # define WIN32_LEAN_AND_MEAN
32 # if !HAVE_DECL_GETLOGIN
33 extern char *getlogin (void);
37 /* See unistd.in.h for documentation. */
39 getlogin_r (char *name, size_t size)
42 #if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
43 /* Native Windows platform. */
46 /* When size > 0x7fff, the doc says that GetUserName will fail.
47 Actually, on Windows XP SP3, it succeeds. But let's be safe,
48 for the sake of older Windows versions. */
52 if (!GetUserName (name, &sz))
54 if (GetLastError () == ERROR_INSUFFICIENT_BUFFER)
55 /* In this case, the doc says that sz contains the required size, but
56 actually, on Windows XP SP3, it contains 2 * the required size. */
63 /* Platform with a getlogin_r() function. */
64 int ret = getlogin_r (name, size);
66 if (ret == 0 && memchr (name, '\0', size) == NULL)
67 /* name contains a truncated result. */
71 /* Platform with a getlogin() function. */
78 /* ENOENT is a reasonable errno value if getlogin returns NULL. */
79 return (errno != 0 ? errno : ENOENT);
84 memcpy (name, n, nlen + 1);