Chapter
2. Getting Started with Perl
Perl is
a popular programming
language that's
extensively used in areas such as bioinformatics and web programming.
Perl has become popular with biologists because it's so
well-suited to several bioinformatics tasks.
Perl is also an application, just like any other application you
might install on your computer. It is available (at no cost) and runs
on all the operating systems found in the average biology lab (Unix
and Linux, Macintosh, Windows, VMS, and more).[1]
The Perl application on your
computer takes a Perl language program (such as one of the programs
you will write in this book), translates it into instructions the
computer can understand, and runs (or "executes") it.
So, the word Perl refers both to the language in
which you will write programs and to the application on your computer
that runs those programs. You can always tell from context which
meaning is being used.
Every computer language such as Perl needs to have a
translator
application (called an interpreter or compiler) that can turn
programs into instructions the computer can actually run. So the Perl
application is often referred to as the Perl interpreter, and it
includes a Perl compiler as well. You will often see Perl programs
referred to as
Perl
scripts or Perl code. The terms program, application, script, and
executable are somewhat interchangeable. I refer to them as
"programs" in this book.