"The "-x" option is good for hunting down what shell is
running what script. You can usually find this out by backtracing
the PID from child to parent and so forth, by running "file"
against the script itself or just checking your ps output. In the
case where you have a script, showing up in your process table,
that doesn't have an obvious point of origin for you to examine,
this option is a pretty quick way to figure out the invoking
shell."