% uname -a
SunOS herdubreid.rhi.hi.is 5.9 Generic_118558-27 sun4u sparc SUNW,Sun-Fire-880
% cat test.pl
#!/usr/bin/perl

use strict;
use warnings;

use FindBin;

print "zeroth argument: $0\n";
print "path to binary : $FindBin::RealScript\n";
% ls -l test.pl
-rwx------   1 tcc1     enem         138 Jun 12 15:58 test.pl
% ./test.pl
zeroth argument: ./test.pl
path to binary : test.pl
% chmod u+s test.pl
% ./test.pl
Cannot find current script '/dev/fd/4' at /usr/perl5/5.6.1/lib/FindBin.pm line 166
BEGIN failed--compilation aborted at /usr/perl5/5.6.1/lib/FindBin.pm line 166.
Compilation failed in require at /dev/fd/4 line 6.
BEGIN failed--compilation aborted at /dev/fd/4 line 6.