Programming Perl, 4th Edition

Location of Perl

Although this may seem obvious, Perl is useful only when users can find it easily. When possible, it’s good for both /usr/bin/perl and /usr/local/bin/perl to be symlinks to the actual binary. If that can’t be done, system administrators are strongly encouraged to put Perl and its accompanying utilities into a directory typically found along a user’s standard PATH, or in some other obvious and convenient place.

In this book, we use the standard #!/usr/bin/perl notation on the first line of the program to mean whatever particular mechanism works on your system. If you care about running a specific version of Perl, use a specific path:

#!/usr/local/bin/perl5.14.0

If you just want to be running at least some version number but don’t mind higher ones, place a statement like this near the top of your program:

use v5.14;

(Note: Ancient versions of Perl used numbers like “5.005” or “5.004_05”. Nowadays we would think of those as v5.5.0 and v5.4.5, but versions of Perl older than v5.6.0 won’t understand that notation. The use 5.NNN form is safest to ensure backward compatibility stretching back into the previous millennium.)