add getlogin from gnulib

* lib/Makefile.am:
* lib/getlogin.c:
* m4/getlogin.m4:
* m4/gnulib-cache.m4: Add getlogin module.

lib/Makefile.am

@@ -21,7 +21,7 @@
 # the same distribution terms as the rest of that program.
 #
 # Generated by gnulib-tool.
-# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil clock-time close connect dirfd duplocale environ extensions flock floor fpieee frexp fstat full-read full-write func gendocs getaddrinfo getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nl_langinfo nproc open pipe-posix pipe2 putenv recv recvfrom regex rename select send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat times trunc verify vsnprintf warnings wchar
+# Reproduce by: gnulib-tool --import --dir=. --local-dir=gnulib-local --lib=libgnu --source-base=lib --m4-base=m4 --doc-base=doc --tests-base=tests --aux-dir=build-aux --lgpl=3 --no-conditional-dependencies --libtool --macro-prefix=gl --no-vc-files accept alignof alloca-opt announce-gen autobuild bind byteswap canonicalize-lgpl ceil clock-time close connect dirfd duplocale environ extensions flock floor fpieee frexp fstat full-read full-write func gendocs getaddrinfo getlogin getpeername getsockname getsockopt git-version-gen gitlog-to-changelog gnu-web-doc-update gnupload havelib iconv_open-utf inet_ntop inet_pton isinf isnan ldexp lib-symbol-versions lib-symbol-visibility libunistring listen localcharset locale log1p maintainer-makefile malloc-gnu malloca nl_langinfo nproc open pipe-posix pipe2 putenv recv recvfrom regex rename select send sendto setenv setsockopt shutdown socket stat-time stdlib strftime striconveh string sys_stat times trunc verify vsnprintf warnings wchar
 
 AUTOMAKE_OPTIONS = 1.5 gnits subdir-objects
 
@@ -577,6 +577,15 @@ EXTRA_libgnu_la_SOURCES += gai_strerror.c getaddrinfo.c
 
 ## end   gnulib module getaddrinfo
 
+## begin gnulib module getlogin
+
+
+EXTRA_DIST += getlogin.c
+
+EXTRA_libgnu_la_SOURCES += getlogin.c
+
+## end   gnulib module getlogin
+
 ## begin gnulib module getpeername
 
 

lib/getlogin.c

@@ -0,0 +1,41 @@
+/* Provide a working getlogin for systems which lack it.
+
+   Copyright (C) 2010-2013 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU Lesser General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Bruno Haible, 2010.  */
+
+#include <config.h>
+
+/* Specification.  */
+#include <unistd.h>
+
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+# define WIN32_LEAN_AND_MEAN
+# include <windows.h>
+#endif
+
+char *
+getlogin (void)
+{
+#if (defined _WIN32 || defined __WIN32__) && ! defined __CYGWIN__
+  static char login_name[1024];
+  DWORD sz = sizeof (login_name);
+
+  if (GetUserName (login_name, &sz))
+    return login_name;
+#endif
+  return NULL;
+}