That method seems very promising. The
hulu.sh script is written for Cygwin, but I borrowed a little from it.
Code:
$ MOZ_DISABLE_OOP_PLUGINS=1 firefox -no-remote -profile . <URL>
[1] 30552
$ ./dump-pid.sh 30552
$ strings -10 *.dump | grep -B 1 "Connection succeeded\."
I8772LDKksadhGHGagf#
Connection succeeded.
The complicated Firefox invocation avoids interference with running Firefoxies,
dump-pid.sh comes from Server Fault, and the final grep is highly experimental, since I’ve only tested this once so far. Thanks!