use File::Spec;
my @exec = map { my $p = $_; grep { -f and -x } map File::Spec->catfile($p, "$f$_"), '', qw(.exe .com .bat) } File::Spec->path
  or die "Can't find executable $f";

##</code><code>##

#!/usr/bin/perl -wl
use File::Which;
open OUT, '>complexe'; close OUT;
print for which('complexe');

##</code><code>##

.\complexe