Simple strace debugging

Today my URxvt terminals are stuck. All of them, at the same time.

I know they're just clients (urxvtc) for the main daemon (urxvtd) so I'm not surprised that all of them are stuck, but I don't know why.

URxvt standalone version (urxvt) works well, so I can start inverstigating (by the way, in my i3 environment I mainly use URxvt client (bound to Mod+Shift+Enter), because it's faster to start, but I have a backup binding Mod+Ctrl+Enter for the standalone version, just in case things like that happen :).

Then, with the right tool, it's easy to find the problem:

 $ strace -p $(pidof urxvtd)
 strace: Process 1518 attached
 wait4(20063, 
 ^C
strace: Process 1518 detached
 <detached ...>

So PID 20063 is the problem, urxvtd is waiting for it forever. But who is that?

$ ps aux | grep 20063 
kevin    20063  0.0  0.0  13628  2920 ?        S    10:45   0:00 sh -c echo -en toto\.ods | xsel -i -b -p

Alright, it's my clipboard management script that doesn't return ...

$ kill -9 20063

Bye bye clipboard, and hello again my terminals :-)