~/test/foo/bar> touch bla
~/test/foo/bar> ls -a
.  ..  bla
~/test/foo/bar> cat > ~/perl/test/opendirtest.pl
#!/usr/bin/perl -l
opendir DIR, '.' or die $!;
print for readdir DIR;
~/test/foo/bar> chmod +x ~/perl/test/opendirtest.pl
~/test/foo/bar> ~/perl/test/opendirtest.pl
.
..
bla