t/run/runenv.t Test if perl honors its environment variables.
t/run/switcha.t Test the -a switch
t/run/switchC.t Test the -C switch
-t/run/switches.t Tests for the other switches
+t/run/switches.t Tests for the other switches (-0, -l, -c, -s, -M, -m, -V)
t/run/switchF.t Test the -F switch
t/run/switchI.t Test the -I switch
t/run/switchn.t Test the -n switch