You might find this instructive, it was a comment by John Krahn, about this obfu.

# krahn
# Just change the "s;;$_;see" at the end to "print" to
# see the command as it really is

perl -le '$??s:;s:s;;$?::s;;=]=>%-{<-|}<&|`{;;y; -/:-@[-`{-};`-{/" -;;
+print'
[download]