How to protect your PDF files with open source tools

nospam@example.com (Marcus Friedman) — Tue, 14 Apr 2009 20:00:00 -0700

When you need to distribute documents in PDF format, you’ll probably want to protect them. If you are working on Mac OS X (or Windows) and you have Adobe Acrobat, that can be done quite easily.

But if you’re running Linux on your desktop —or even if you’re using Windows or a Mac and don’t want to use proprietary programs—, there are free tools that will let you protect your files by adding encryption, passwords and restrictions.

One of those tools is pdftk (the pdf toolkit). On Debian and Ubuntu, pdftk is already present in the official repositories, so all you have to do to install it is:

apt-get install pdftk

In the product’s website you’ll also find binary packages for FreeBSD, Mac OS X and Windows.

Here are some examples that show you how to use the program:

Encrypt a PDF using 128-Bit Strength (the default) and withhold all permissions:
pdftk mydoc.pdf output mydoc.128.pdf owner_pw foopass
Same as above, except that a password is required to open the PDF:
pdftk mydoc.pdf output mydoc.128.pdf owner_pw foo user_pw baz
Same as above, except that printing is allowed (after the PDF has been opened):
pdftk mydoc.pdf output mydoc.128.pdf owner_pw foo user_pw baz allow printing

Besides the security functions, pdftk has many more features that you might find useful too, including the ability to merge, split and rotate PDF documents, or applying watermarks.

Broadcatching with open source tools

nospam@example.com (Marcus Friedman) — Fri, 20 Mar 2009 20:00:00 -0700

Broadcatching can be defined as the downloading of digital content that has been made available over the Internet through RSS feeds. Instead of having to spend time visiting multiple websites to find the contents that you want to download, you just need to find a relevant RSS feed and add it to your broadcatching client. The program will monitor the feed, and when it finds new contents it will let you know, allowing you to start new downloads with a single click. You can even tell the broadcatching client to download new contents for you as they become available, so the whole process becomes fully automated.

If you want to know how to take advantage of broadcatching by using open source programs (on Linux, Mac OS X or Windows), please read on.

Please note that downloading copyrighted television broadcasts is not considered legal in some countries or states. The purpose of this article is to give you an overview of some open source tools available for broadcatching. It is up to the readers to decide if or how they should use such tools.

ellipsys (Entries tagged as cool solutions)

How to protect your PDF files with open source tools

Broadcatching with open source tools