Is there a command line entry that returns a value that can be used to determine if the N900 is in Silent or General profile?

I am using a timed shell script which calls play-sound to play clock chimes, the disadvantage of which is that play-sound will always play, even when the phone's profile is set to Silent.

I need something to exit or otherwise control the shell script, along the lines of
if {
IsProfileSilent() == true
} exit;