D:\>perl -wle "`exit 1`; print $?;"
256

D:\>perl -wle "`exit(1)`; print $?;"
0

D:\>perl -wle "`exit 2`; print $?;"
512

D:\>perl -wle "`exit(2)`; print $?;"
0

D:\>perl -wle "$x = 1;`exit $x`; print $?;"
256

D:\>perl -wle "$x = 1;`exit($x)`; print $?;"
0