Added cygwin support.

Patch by Cygwin Ports maintainer <yselkowitz@users.sourceforge.net>.
See #578890.

sysdeps/cygwin/mem.c

@@ -0,0 +1,61 @@
+/* Copyright (C) 1998-99 Martin Baulig
+   This file is part of LibGTop 1.0.
+
+   Contributed by Martin Baulig <martin@home-of-linux.org>, April 1998.
+
+   LibGTop is free software; you can redistribute it and/or modify it
+   under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2 of the License,
+   or (at your option) any later version.
+
+   LibGTop 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 General Public License
+   for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with LibGTop; see the file COPYING. If not, write to the
+   Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+   Boston, MA 02111-1307, USA.
+*/
+
+#include <config.h>
+#include <glibtop/error.h>
+#include <glibtop/mem.h>
+
+#include "glibtop_private.h"
+
+static const unsigned long _glibtop_sysdeps_mem =
+(1L << GLIBTOP_MEM_TOTAL) + (1L << GLIBTOP_MEM_USED) +
+(1L << GLIBTOP_MEM_FREE) + (1L << GLIBTOP_MEM_SHARED) +
+(1L << GLIBTOP_MEM_USER);
+
+/* Init function. */
+
+void
+_glibtop_init_mem_s (glibtop *server)
+{
+	server->sysdeps.mem = _glibtop_sysdeps_mem;
+}
+
+/* Provides information about memory usage. */
+
+#define FILENAME	"/proc/meminfo"
+
+void
+glibtop_get_mem_s (glibtop *server, glibtop_mem *buf)
+{
+	char buffer [BUFSIZ];
+
+	memset(buf, 0, sizeof *buf);
+
+	file_to_buffer(server, buffer, sizeof buffer, FILENAME);
+
+	buf->total  = get_scaled(buffer, "MemTotal:");
+	buf->free   = get_scaled(buffer, "MemFree:");
+	buf->used   = buf->total - buf->free;
+	buf->shared = 0;
+
+	buf->user = buf->total - buf->free;
+	buf->flags = _glibtop_sysdeps_mem;
+}