$ cat whichperl.pl #!/usr/bin/perl printf "operating system: %s\n executable: %s\n", $^O, $^X, ; #### $ perl whichperl.pl operating system: linux executable: /usr/bin/perl $ chmod +x whichperl.pl $ ./whichperl.pl operating system: linux executable: /usr/bin/perl #### $ perl whichperl.pl operating system: freebsd executable: /usr/local/bin/perl