>perl -wMstrict -le
"my $sw = '/b';
 my $d  = `dir $sw $9`;
 print qq{'$d'};
"
Use of uninitialized value $9 in concatenation (.) or string at -e line 1.
'arb_nested_HoH_1.pl
arb_struct_access_1.pl
arb_struct_access_2.pl
...
most_of_8_1.pl
recurring_cycle.pl
recurring_cycle.pl.bak
'