I’ve seen a lot of questions from new and beginning programmers on various forums and other online communities. A lot of them, albeit, geared toward a particular language, like shell programming, Perl or C; but generally all them are in the Unix variety of environments, primarily Linux. Many times, they are asking how to do a given task in a given language, when that task might be better done in other ways. Yes, there are times where you’ve been hand-cuffed to a particular language or operating environment; but there are generally 1001 ways to skin a cat in Unix and people tend to forget this as they’re picking up a language like Perl, Python, Ruby and others. If you are writing scripts and programs on Unix that operate on the back-end of things — i.e. not CGI or web related and/or dealing with GUI interfaces — you are almost always better off combining your primary language and those smaller scripting languages and other tools that Unix provides for developers to make your life easier, and help keep your code manageable.

In our example, someone on a Perl forum was asking about how to copy a set of files from a directory and it’s sub directories to another single directory. All the files were gzipped, with a .gz extension. Doing this in Perl using File::Find or some other such feature is a bit of overkill for this given task. The Unix shell and accompanying commands it provides can handle this with less typing.

$ find . -name '*.gz' | xargs -I {} mv {} /new/parent/folder/

This is very quick and can even be called from the given Perl script via system() or backticks. Otherwise, doing it in Perl with File::Find would take a number of lines to find the matching files in the given directory tree and then you’d still have to write the Perl code to move the files over to the new directory. Just call the above snippet from your Perl script, check the return results and move on. No need to reinvent the wheel.

For reference, here’s the equivalent operation using Perl only:

#! /usr/bin/perl

use File::Find;
use File::Copy;

my $target = "/new/parent/folder";

find (\&filemove, "./");
exit(0);

sub filemove() {
        return unless -f $File::Find::name && m/\.gz$/;
        move($_, \"$target/$file\");
}

That’s much more coding. And honestly, you’re not saving yourself much portability unless you plan on running this in a non-Unix environment as well. Remember, there’s no problem combining different types of languages or scripts to accomplish the given task. That’s what all those tools are there for to begin with!

Linux/Unix provide developers with a deep and rich tool-set of commands and utilities which they should take advantage of in solving problems.  It was a design goal of Unix to provide discrete commands and tools with very specific functionality that could be combined to solve more complex problems – so why not extend that paradigm to include all the great modern languages and tools that we all use today as well.

Enjoy!