When running a server on linux without keyboard, mouse and monitor, it is
sometimes necessary to excute administrative commands, e.g. changing CD's,
rebooting or shuting down the system, start of the Backup etc.
tty_ctrl offer's the opportunity to execute 7 sommands on such a computer.
Success or Errors while execution of the commands will be displayed via
status led's. Further it starts as a daemon process and all actions
performed are logged by the syslog process, e.g. in the /var/log/messages file.
If you recommend to execute other command than the default ones, simply
create a link in /etc/tty_ctrl/button1..7 to your command, and it will
be executed on the next startup of the program.
Preconditions:
You'll need a free serial line, three resistors, 7 buttons, three led's 6
diodes and of course a soldering pen to get this stuff together.
The hardware should be available at any electronic market, and costs less than 5 EUR(or $).
How does it work?
tty_control monitors the status signals of the serial line. Recieve and
Transmit Data Signals are not not used for this purpose.
The Signals used are: Carrier Detect, Data Set Ready, Clear To Send and Ring Indicator
(4 signals, 3 are the combination of CD & DSR, CTS & CD, DSR & CTS
(Do not try to derive anything from RI & something, this won't work))
The power for driving the led's is derived from the serial line itself.
Depending on the signal whether the default command or the user defined command is executed.
It is not possible to execute 2 commands at one time.
For more details, please refer to the source code
Sorry this page is not available in any other language.
New Hardware site for tty-switch added 2003-12
tty-switch is for switching anything via serial line
Scripts for tty-control Date 2002-04
Some usefull scripts available on the download page.
Version 2.00 Date 2002-01-04
complete redesign of the source code:
default commands are now own scripts
source file has been split, all system calls substituted by execve(), sprintf commands substituted
makefile changed
Redirection of the output to /dev/null is now done by tty_ctrl
Version 1.13 Date 2001-10-04
remove option for deinstallation added to makefile, minor changes in sourcecode
some debian fixes added
Version 1.12 Date 2001-07-08
makefile introduced, all global variables removed
Version 1.11. Date 2001-06-22
Starts as Daemon, all actions are logged, own commands can be executed
Version 1.0. Date 2001-02-02
tty_control - Controlling inputs from serial lines
The Ancestor: cpanel
This Page was created by Peter Pfrang. Last modification 2003-12-16.