tailieunhanh - Apress - Smart Home Automation with Linux (2010)- P56

Apress - Smart Home Automation with Linux (2010)- P56:Linux users can now control their homes remotely! Are you a Linux user who has ever wanted to turn on the lights in your house, or open and close the curtains, while away on holiday? Want to be able to play the same music in every room, controlled from your laptop or mobile phone? Do you want to do these things without an expensive off-the-shelf kit | CHAPTER 7 CONTROL HUBS You can use the same mechanism to invoke software-only devices such as media players and Festival allowing music to be streamed into locations where physical speaker cabling is not possible. The system is bidirectional so you can also get a remote machine to send any commands it gets to the main server for processing. Marple was introduced in version of Minerva and is now supported by all the current Bearskin commands and used transparently to the user. The Workings There are two files necessary to enable Marple s full range of functionality both are called devlist and exist for each of the Bearskin commands that have been enabled. They are formatted thusly localhost dev dev dsp - - default dev dev dsp - - bedroom soap 19781 localhost The columns are as follows in order The device name . This is always the first argument to any of the Bearskin commands such as the bedroom in cdplayer bedroom play 1. Protocol type This currently may be dev or soap. If the protocol is dev then the protocol device represents a Linux-style device on the local machine. If it s soap then the device specifies the IP address of the machine to talk to. Protocol device This indicates which address is to be used for the device. It s usually a device or IP address see the previous item . Protocol parameter This is used in conjuncture with the protocol device. This is mostly unused but in the example earlier it represents the port number associated with the IP address. The remote device name . When the command is being executed on the remote device this name is used instead of the original one given. This parameter is unused for dev protocols. Handling Protocols When the user invokes the cdplayer command for example from either the Web command line or Cosmic the script will examine the local devlist file located at MINBASE etc devices cdplayer devlist for a matching device name in the first column. If no matching device name can be found it then reads