$ dir NUL

 Directory of \\.

File Not Found

$ perl -Mautodie=system -e " system q[dir NUL] "
"dir NUL" unexpectedly returned exit value 255 at (eval 10) line 13.
 at -e line 1

$ perl -Mautodie=system -e " system q[C:\\WINDOWS\\system32\\cmd.EXE /x /c dir NUL] "

 Directory of \\.

File Not Found
"C:\WINDOWS\system32\cmd.EXE /x /c dir NUL" unexpectedly returned exit value 1 at (eval 10) line 13.
 at -e line 1