doing things only once

[wogri at wogri dot com]

Hi,

I have the following scenario: once a key is pressed on my lcd display, an external command should be launched ONCE via exec(). it seems as if such evaluations don't work:

evaluation key == 2 ? exec ('start_something',3000) evaluation2 key == 2 ? key = 1 :

Any help would be appreciated!

[anonymous]

Replying to wogri at wogri dot com:

Hi, I have the following scenario: once a key is pressed on my lcd display, an external command should be launched ONCE via exec(). it seems as if such evaluations don't work: evaluation key == 2 ? exec ('start_something',3000) evaluation2 key == 2 ? key = 1 : Any help would be appreciated!

I had the same problem. I fixed it by executing a script, which tested, if the command is already running. If not, the script launches the command.
For example:
#!/bin/bash
id=0
id=ps ax | grep your_command | awk '{print $1}'
if [ $id -ge 0 ]

then
echo "Programm is already running"
else your_command

fi
exit 0

it's a quite simple solution. try it.