jack -x option not understandable

[era]

The manual states that the -x option causes jack to run a "predefined command" when it finishes, but it is not stated how this command is defined or where and how it can be set.

Running "jack -x eject" causes an error message to be displayed. Running "jack -x=exec_rip_done" does nothing after finishing. From reading the sources, it appears in /usr/share/pyshared/jack_main_loop.py that the value of the configuration variable exec_rip_done is passed to os.system() when -x is present.

Thus, in my case, simply "jack -x" did do what I want, and what it does can be changed by setting exec_rip_done in your ~/.jack3rc.