about auto-activated services

[Colin Walters]

2009/6/2 Edison_lin-林俊翰 <edison_lin at gemtek.com.tw>:
> Hi,
> I send a signal to the dbus-daemon and the process not yet run is then
> brought up. But after that it seems that I couldn't communicate with that
> process. I can see the signal being sent to that process through
> dbus-monitor, but then nothing happened. The printf doesn't work.

The standard input, output, and error streams for activated services
will have been redirected to /dev/null I believe.  If inside your
service you want to get output from printf you'll need to open them
somewhere else such as a log file.

> I tried to
> use system("echo 1234 > /gotSignal"); but still no effect.

My guess with that command is that you don't have permissions to
create new files in the root directory on your OS.  Try instead
writing to say "/tmp/myapp.log" for debugging purposes.  For system
services you could use syslog or another logging facility.