Carlos Rivero

The proliferation of unsolicited email, or spam, is becoming more and
more widespread. However, there are many tools to help prevent spam.
This week, we look at using Procmail and SpamAssassin to filter
incoming mail and to block incoming spam. Procmail
is a mail filter than can be used to sort incoming mail into separate
folders as well as many other types of mail preprocessing. SpamAssassin is a mail filter that uses heuristic scanning to identify spam.

Since both Procmail and SpamAssassin are in Portage, installation is a simple emerge.

Javascript Demo for converting qwerty to dvorak without having to change your operating system settings

GNU Privacy Guard (GnuPG) is an open source version of the commercial
Pretty Good Privacy (PGP) software for creating digital signatures.
This weeks Tips and Tricks will cover the creation of a key, exporting
your key to a public keyserver, and finally adding your digital
signature to email.

Gentoo ebuilds sometimes require post-install configuration. Typically
these ebuilds will notify you of any necessary commands to run.
However, when running an emerge update world, these notices can scroll
by very quickly and get lost as subsequent packages are installed. To
get around this, we can send the output of emerge to a logfile. We use
the 'tee' command to accomplish this since 'tee' allows us to watch the
emerge in process in addition to writing to a file.

Most Gentoo users are familiar with the Portage system used to install software. One of the features that you may not be familiar with is that Portage can also update your entire system at once. This is known as an 'update world'.

To run an update world, use the following command:

New Gentoo users often ask how to get a list of installed packages from the
Portage tree, but what many of those who give answers might not know
is the abundance of tools that can be used to do so. From Portage's pkglist,
the gentoolkit's qpkg and epm(an rpm work-alike), to walking the /var/db/pkg/
directory structure yourself, there are definitely quite a few choices.
Here are two ways to list all installed packages, first using pkglist (found
in /usr/lib/portage/bin/, which is often not in $PATH), the second running
find on /var/db/pkg/:

Have you ever tried to restart a crashed service and gotten the
following error message?

    * WARNING: service name has already been started
    

If so, you can manually reset the service with the following command