On my private network I have a backup server, which runs a bacula backup every night. To save energy I use a cron job to wake the server, but I haven't found out, how to properly shut it down after the backup is done. 
By the means of the bacula-director configuration I can call a script during the processing of the last backup job (i.e. the backup of the file catalog). I tried to use this script: 

```
#!/bin/bash
# shutdown server in 10 minutes
#
# ps, 17.11.2013
bash -c "nohup /sbin/shutdown -h 10" &
exit 0

```

The script shuts down the server - but apparently it returns just during the shutdown, 
and as a consequence that last backup job hangs just until the shutdown. How can I make the script to file the shutdown and return immediately?

Update: After an extensive search I came up with a (albeit pretty ugly) solution: 
The script run by bacula looks like this: 

```
#!/bin/bash
at -f /root/scripts/shutdown_now.sh now + 10 minutes

```

And the second script (shutdown\_now.sh) looks like this: 

```
#!/bin/bash
shutdown -h now

```

Actually I found no obvious method to add the required parameters of shutdown in the syntax of the 'at' command. Maybe someone can give me some advice here.