reworking messages

1) start 'bin/secop-server test'
2) connect to localhost port 10767
3) enter help<enter>
4) enjoy

Change-Id: I488d5f9cdca8c91c583691ab23f541a4a8759f4e

secop/lib/pidfile.py

@@ -0,0 +1,55 @@
+#  -*- coding: utf-8 -*-
+# *****************************************************************************
+#
+# This program 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.
+#
+# 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 General Public License for more
+# details.
+#
+# You should have received a copy of the GNU General Public License along with
+# this program; if not, write to the Free Software Foundation, Inc.,
+# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+#
+# Module authors:
+#   Enrico Faulhaber <enrico.faulhaber@frm2.tum.de>
+#
+# *****************************************************************************
+
+"""Define pidfile helpers"""
+import os
+import atexit
+import psutil
+
+
+def read_pidfile(pidfile):
+    """read the given pidfile, return the pid as an int
+
+    or None upon errors (file not existing)"""
+    try:
+        with open(pidfile, 'r') as f:
+            return int(f.read())
+    except (OSError, IOError):
+        return None
+
+
+def remove_pidfile(pidfile):
+    """remove the given pidfile, typically at end of the process"""
+    os.remove(pidfile)
+
+
+def write_pidfile(pidfile, pid):
+    """write the given pid to the given pidfile"""
+    with open(pidfile, 'w') as f:
+        f.write('%d\n' % pid)
+    atexit.register(remove_pidfile, pidfile)
+
+
+def check_pidfile(pidfile):
+    """check if the process from a given pidfile is still running"""
+    pid = read_pidfile(pidfile)
+    return False if pid is None else psutil.pid_exists(pid)