Shutter signals in Multi User Env

[Rui Lapa]

When running in a multi-user environment, shutter doesn't work correctly.

This is due to lines 6037-6080 "pidof" returning pids of all the other users processes and "probably" signalling the other user process and dying before actually reaching the respective user shutter process.

These are the probable solutions, with a little comment:

1 - signaling all processes and "die"ing after the "foreach" cycle
     Fast patch!
     Doesn't avoid multiple shutter processes signalling, causing multiple "shots".

2 - replacing "pidof ..." with "pgrep -d ' ' -u $< -f /usr/bin/shutter" and maintaing the rest of the code
    Limits to user shutter processes, but allows multiple shutter processes, only signalling one!
    Depends on "procps" package, not a problem!

3 - directly calling "pkill -SIGNAL -u $< -f /usr/bin/shutter"
    Fast patch!
    Signals all users shutters process... causing multiple "shots".
    Depends on "procps" package, not a problem!

4 - creating a pid file in .shutter dir
     Requires checking for "stalled" pid file on start, caused by "FS failures"
     Avoids multiple shutter instances

In my opinion I prefer solution 2 for the short time solution, but I think that number 4 would be the "preferred" method.

There maybe other solutions like using Unix::PID, File::PID, ...

[Rui Lapa (rui-lapa)]

A little more explanation:

 I'm not running any shutter process.
 I'm calling it via gnome gconf "shortcuts" with "shutter --window" and "shutter --full", like so:

gconftool-2 --direct --set /apps/metacity/keybinding_commands/command_window_screenshot '/usr/bin/shutter --window'
gconftool-2 --direct --set /apps/metacity/keybinding_commands/command_screenshot '/usr/bin/shutter --full'

[Mario Kemper (Romario) (mario-kemper)]

Thank you very much for your detailed explanations, Rui Lapa.

I've implemented solution 2 as you recommended. In the long run I am planning to substitute the current signal mechanism with a D-BUS solution, but this solution will do the job until I've time to start with that.

Regards
Mario