>perl -e"print `dir /b`"
bar
foo

Windows:
>perl -le"`nonexistant`; print $?; print $! if $?==-1"
'nonexistant' is not recognized as an internal or external command,
operable program or batch file.
256

unix:
$ perl -le'`nonexistant`; print $?; print $! if $?==-1'
-1
No such file or directory