i have the same problem - i want to run the following perl script helloworld.pl #!/usr/bin/perl print "Hello World!\n"; it runs if i type perl helloworld.pl in the command line but, if i try to run the script without calling perl explicitly in the command line (i.e. helloworld), i get "command not found". i'm absolutely sure that i'm running the program from the correct path and that perl is located in /usr/bin/ - i used which perl. what's going on guys?