So, are you saying that it is still the case, when you run "example2.pl" as a shell command line (i.e. in a Terminal window or xterm), the script does not wait for input from the keyboard? I don't get that sort of behavior on my mac -- I stored the four-line script to a file called "example2.pl", just as you posted it, and when I run "example2.pl" as a command in a shell, it shows the prompt, waits for me to hit "return", and echos whatever I typed before hitting "return".

If you were running the script with input redirection ( example2.pl < some.file ) or if you were piping data from some other process to the script ( other_process | example2.pl), then of course the script won't wait for input from the keyboard, because STDIN is tied to a file or a pipe, respectively. But you probably knew that already, being familiar with unix.

Also (of course) if you type "example2.pl" at the shell prompt, and then hit "return" twice in a row, the second return will be taken as input at line 3 of the script, and it will finish, echoing an empty string.