note rnahi <p>What you say does not agree to the docs and to my practice.</p> <code> $ cat whichperl.pl #!/usr/bin/perl printf "operating system: %s\n executable: %s\n", $^O, $^X, ; </code> <p>And see the results:</p> <code> $ perl whichperl.pl operating system: linux executable: /usr/bin/perl $ chmod +x whichperl.pl $ ./whichperl.pl operating system: linux executable: /usr/bin/perl </code> <p>And later, to another OS:</p> <code> $ perl whichperl.pl operating system: freebsd executable: /usr/local/bin/perl </code> 495992 495998