Checking for mydata in ../datadir:

$FindBin::RealBin        : /var/tmp/mydir/../datadir     passed
dirname($0)              : /usr/local/bin/../datadir     failed
dirname($name)           : ../../mydir/../datadir        failed
dirname(rel2abs($0))     : /usr/local/bin/../datadir     failed
dirname(rel2abs($name1)) : /var/tmp/otherdir/symdir/../datadir   failed