dbuscrontab utility script

diff --git a/dbuscrontab.py b/dbuscrontab.py
new file mode 100755 (executable)
index 0000000..b816cc8
--- /dev/null
+++ b/dbuscrontab.py
@@ -0,0 +1,51 @@
+#!/usr/bin/python
+
+import os, sys, shutil, signal, tempfile, pipes
+crontab = '/etc/dbuscrontab'
+pidfile = '/var/run/dbuscron.pid'
+
+def create_temp_file(orig_file):
+    try:
+        temp_file = tempfile.mktemp(prefix=os.path.basename(orig_file))
+        shutil.copy(orig_file, temp_file)
+        return temp_file
+    except:
+        raise SystemError('Unable to make copy of dbuscrontab file.')
+
+def run_system_editor(filename):
+    editor = pipes.quote(os.environ.get('EDITOR', '/usr/bin/vim'))
+    if os.system(editor + ' ' + pipes.quote(filename)) != 0:
+        raise SystemError('Editor returned non-zero status value.')
+
+def get_dbuscron_pid():
+    try:
+        f = os.popen('initctl status dbuscron', 'r')
+        status = f.readline()
+        f.close()
+        return int(status.strip().split(' ').pop())
+    except:
+        raise SystemError('Unable to get PID of dbuscron job.')
+
+if __name__ == '__main__':
+
+# 1. create temporary config file copy
+    temp_file = create_temp_file(crontab)
+    mod_time = os.path.getmtime(temp_file)
+
+# 2. run system editor on this file
+    run_system_editor(temp_file)
+
+# 3. check if this file is changed
+    if os.path.getmtime(temp_file) <= mod_time:
+        print 'File was not changed.'
+        sys.exit(2)
+
+# TODO: 4. check this file's syntax
+
+# 5. replace system wide config file with new one
+    shutil.move(temp_file, crontab)
+
+# 6. send sighup to dbuscron daemon
+    pid = get_dbuscron_pid()
+    os.kill(pid, signal.SIGHUP)
+