How can I set devilspie to detect if an application was started with the flag --hello-world from terminal?
For example window_name detects the window title. How can transform in devilspie the following sentence: if one of flags is --hello-world?
(if (is (window_name) 'My-title')
(begin
...
)
)
You have not specified if you are using the obsolete devilspie or the newer devilspie2. In any case, as far as I can tell from their manuals, neither one of them has access to the information you want.
Devilspie is a window matching utility, it interacts with the X server. The commandline switches you give when you launch a program are not passed to the X server since they only affect the way the program is launched and are internal switches of that particular piece of software.
The closest seems to be the get_application_name() call but I doubt that would include the command line arguments. You might be able to do what you need using xdotool (see here) and parsing the output of ps aux or pgrep -al $APP_NAME.
References:
