Linux!

Unix has become the primo operating system of the Internet. In fact, Unix is the most widely used operating
system in the world among computers with more power than PCs.
True, Windows NT is coming up fast as a common Internet operating system, and is sooo wonderfully
buggy that it looks like it could become the number one favorite to crack into. But today Unix in all its
wonderful flavors still is the operating system to know in order to be a truly elite hacker.
So far we have assumed that you have been hacking using a shell account that you get through your
Internet Service Provider (ISP). A shell account allows you to give Unix commands on one of your ISP's
computers. But you don't need to depend on your ISP for a machine that lets you play with Unix. You can
run Unix on your own computer and with a SLIP or PPP connection be directly connected to the Internet.
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Newbie note: Serial Line Internet Protocol (SLIP) and Point-to-Point Protocol (PPP) connections give you a
temporary Internet Protocol (IP) address that allows you to be hooked directly to the Internet. You have to
use either SLIP or PPP connections to get to use a Web browser that gives you pictures instead on text
only. So if you can see pictures on the Web, you already have one of these available to you.
The advantage of using one of these direct connections for your hacking activities is that you will not leave
behind a shell log file for your ISP's sysadmin to pore over. Even if you are not breaking the law, a shell log
file that shows you doing lots of hacker stuph can be enough for some sysadmins to summarily close your
account.
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What is the best kind of computer to run Unix on? Unless you are a wealthy hacker who thinks nothing of
buying a Sun SPARC workstation, you'll probably do best with some sort of PC. There are almost countless
variants of Unix that run on PCs, and a few for Macs. Most of them are free for download, or inexpensively
available on CD-ROMs.
The three most common variations of Unix that run on PCs are Sun's Solaris, FreeBSD and Linux. Solaris
costs around $700. Enough said. FreeBSD is really, really good. But you con't find many manuals or
newsgroups that cover FreeBSD.
Linux, however, has the advantage of being available in many variants (so you can have fun mixing and
matching programs from different Linux offerings). Most importantly, Linux is supported by many manuals,
news groups, mail lists and Web sites. If you have hacker friends in your area, most of them probably use
Linux and can help you out.
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Historical note: Linux was created in 1991 by a group led by Linus Torvalds of the University of Helsinki.
Linux is copyrighted under the GNU General Public License. Under this agreement, Linux may be
redistributed to anyone along with the source code. Anyone can sell any variant of Linux and modify it and
repackage it. But even if someone modifies the source code he or she may not claim copyright for anything
created from Linux. Anyone who sells a modified version of Linux must provide source code to the buyers
and allow them to reuse it in their commercial products without charging licensing fees. This arrangement is
known as a "copyleft."
Under this arrangement the original creators of Linux receive no licensing or shareware fees. Linus Torvalds
and the many others who have contributed to Linux have done so from the joy of programming and a sense
of community with all of us who will hopefully use Linux in the spirit of good guy hacking. Viva Linux! Viva
Torvalds!
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Linux consists of the operating system itself (called the "kernel") plus a set of associated programs.
The kernel, like all types of Unix, is a multitasking, multi-user operating system. Although it uses a different
file structure, and hence is not directly compatible with DOS and Windows, it is so flexible that many DOS
and Windows programs can be run while in Linux. So a power user will probably want to boot up in Linux
and then be able to run DOS and Windows programs from Linux.
Associated programs that come with most Linux distributions may include:
* a shell program (Bourne Again Shell -- BASH -- is most common);
* compilers for programming languages such as Fortran-77 (my favorite!), C, C++, Pascal, LISP, Modula-2,
Ada, Basic (the best language for a beginner), and Smalltalk.;
* X (sometimes called X-windows), a graphical user interface
* utility programs such as the email reader Pine (my favorite) and Elm

What types of Linux work best? It depends on what you really want. Redhat Linux is famed for being the
easiest to install. The Walnut Creek Linux 3.0 CD-ROM set is also really easy to install -- for Linux, that is!
My approach has been to get lots of Linux versions and mix and match the best from each distribution.
I like the Walnut Creek version best because with my brand X hardware, its autodetection feature was a lifesaver.
INSTALLING LINUX is not for the faint of heart! Several tips for surviving installation are:
1) Although you in theory can run Linux on a 286 with 4 MB RAM and two floppy drives, it is *much*
easier with a 486 or above with 8 MB RAM, a CD-ROM, and at least 200 MB free hard disk space.
2) Know as much as possible about what type of mother board, modem, hard disk, CD-ROM, and video card
you have. If you have any documentation for these, have them on hand to reference during installation.
3) It works better to use hardware that is name-brand and somewhat out-of-date on your computer. Because
Linux is freeware, it doesn't offer device drivers for all the latest hardware. And if your hardware is like mine -
- lots of Brand X and El Cheapo stuph, you can take a long time experimenting with what drivers will work.
4) Before beginning installation, back up your hard disk(s)! In theory you can install Linux without harming
your DOS/Windows files. But we are all human, especially if following the advice of point 7).
5) Get more than one Linux distribution. The first time I successfully installed Linux, I finally hit on
something that worked by using the boot disk from one distribution with the CD-ROM for another. In any
case, each Linux distribution had different utility programs, operating system emulators, compilers and more.
Add them all to your system and you will be set up to become beyond elite.
6) Buy a book or two or three on Linux. I didn't like any of them! But they are better than nothing. Most
books on Linux come with one or two CD-ROMs that can be used to install Linux. But I found that what was
in the books did not exactly coincide with what was on the CD-ROMs.
7) I recommend drinking while installing. It may not make debugging go any faster, but at least you won't
care how hard it is.
Now I can almost guarantee that even following all these 6 pieces of advice, you will still have problems
installing Linux. Oh, do I have 7 advisories up there? Forget number 7. But be of good cheer. Since everyone
else also suffers mightily when installing and using Linux, the Internet has an incredible wealth of resources
for the Linux -challenged.
If you are allergic to getting flamed, you can start out with Linux support Web sites.
The best I have found is http://sunsite.unc.edu:/pub/Linux/. It includes the Linux Frequently Asked
Questions list (FAQ), available from
sunsite.unc.edu:/pub/Linux/docs/FAQ.
In the directory /pub/Linux/docs on sunsite.unc.edu you'll find a number of other documents about Linux,
including the Linux INFO-SHEET and META-FAQ,
The Linux HOWTO archive is on the sunsite.unc.edu Web site at: /pub/Linux/docs/HOWTO. The directory
/pub/Linux/docs/LDP contains the current set of LDP manuals.
You can get ``Linux Installation and Getting Started'' from sunsite.unc.edu in /pub/Linux/docs/LDP/installguide.
The README file there describes how you can order a printed copy of the book of the same name
(about 180 pages).
Now if you don't mind getting flamed, you may want to post questions to the amazing number of Usenet
news groups that cover Linux. These include:
comp.os.linux.advocacy Benefits of Linux compared
comp.os.linux.development.system Linux kernels, device drivers
comp.os.linux.x Linux X Window System servers
comp.os.linux.development.apps Writing Linux applications
comp.os.linux.hardware Hardware compatibility
comp.os.linux.setup Linux installation
comp.os.linux.networking Networking and communications
comp.os.linux.answers FAQs, How-To's, READMEs, etc.
linux.redhat.misc
alt.os.linux Use comp.os.linux.* instead
alt.uu.comp.os.linux.questions Usenet University helps you
comp.os.linux.announce Announcements important to Linux
comp.os.linux.misc Linux-specific topics
Want your Linux free? Tobin Fricke has pointed out that "free copies of Linux CD-ROMs are available the
Linux Support & CD Givaway web site at http://emile.math.ucsb.edu:8000/giveaway.html. This is a project
where people donate Linux CD's that they don't need any more. The project was seeded by Linux Systems
Labs, who donated 800 Linux CDs initially! Please remember to donate your Linux CD's when you are done
with them. If you live near a computer swap meet, Fry's, Microcenter, or other such place, look for Linux
CD's there. They are usually under $20, which is an excellent investment. I personally like the Linux
Developer's Resource by Infomagic, which is now up to a seven CD set, I believe, which includes all major
Linux distributions (Slackware, Redhat, Debian, Linux for DEC Alpha to name a few)plus mirrors of
tsx11.mit.edu and sunsite.unc.edu/pub/linux plus much more. You should also visit the WONDERFUL linux
page at
http://sunsite.unc.edu/linux, which has tons of information, as well as the
http://www.linux.org/. You might also want to check out
http://www.redhat.com/ and http://www.caldera.com/ for more
information on commercial versions of linux (which are still freely available under GNU)."
How about Linux security? Yes, Linux, like every operating system, is imperfect. Eminently hackable, if you
really want to know. So if you want to find out how to secure your Linux system, or if you should come
across one of the many ISPs that use Linux and want to go exploring (oops, forget I
wrote that), here's where you can go for info:
ftp://info.cert.org/pub/cert_advisories/CA -94:01.network.monitoring.attacks
ftp://info.cert.org/pub/tech_tips/root_compromise
http://bach.cis.temple.edu/linux/linux-security/
http://www.geek-girl.com/bugtraq/
There is also help for Linux users on Internet Relay Chat (IRC). Ben (cyberkid@usa.net)
hosts a channel called #LinuxHelp on the Undernet IRC server.
Last but not least, if you want to ask Linux questions on the Happy Hacker list, you're welcome. We may be
the blind leading the blind, but what
the heck!