Beginning Linux

I find I'm recently getting inquiries from various friends and business associates who say they want to try Linux. So I thought I'll post about it here. I'm not an expert by any means, and it's late at night and I need to catch some zzz's, but hopefully this post might help some.

So far I've used three Linux distributions (or distros): Xandros, Ubuntu and Gentoo.

Before I continue, the word distro just inspired me to write this post on my other blog:
http://arkaroy.blogspot.com/2008/03/ending-words-with-o.html

Anywhoo, back to my Linux experience.

1) Xandros is very Window-like. It was a good transition for someone like myself coming from Windows. However it is a very minor distro and the community is not very large. A large community results in more standards, more ports of drivers etc. so it is more usable, and there is more support. Of course the Linux kernel is the same regardless of distribution and thus most drivers should work across the board, but in practice most non-hardcore users are helped greatly by distribution-specific installers and availability on package managers.

2) Ubuntu was very pleasant. It has a great GUI and a large community.

Of course the GUI, like anything else in Linux, is customizable in any distribution, but in this post I am only interested in describing the state of things as they are out of the box. That is the audience for whom I write, and compared to whom I am not all that much ahead on the curve either.

I can't recall what may have been any minus points with Ubuntu. Of course, compared to Windows, there are several usability drawbacks stemming from the lack of drivers or application software for some specific pieces of equipment like printers, cell phone, iPod, etc.

3) Gentoo is not pleasant. I only use it because I have to for one of my clients. It is very bare-bones. The installation of major packages is extremely time-consuming because its package manager doesn't have binaries, just source so EVERYTHING has to be compiled. Firefox took ages to compile (whereas in Ubuntu I think it was available right out of the box). I've heard that installing and setting up OpenOffice can take a good chunk of your day. Some people like this DIY approach but I certainly have better things to do.

Of course the advantage is that you only end up with exactly what you want or need. Such zen-like minimalism may be aesthetically pleasing but let's face it, hard disk space is a cheap commodity, heading inexorably toward dirt-cheap-dom, whereas for me (and doubtless you too) time just gets more and more precious.

I will write more going forward on Linux, and hopefully this is a helpful start for some.

Serial terminal on Linux

Here's another guy who's trying to overcome serial port issues on Linux, and provides some good information.

BI-BA-BO: ttyS0 - terminal on serial connection

Information overload

What with my variety of projects going on at the moment, I find I am having to study some bizarrely disparate topics all at the same time.

Here is what I have on my reading list at the moment:

Web development

• Movable Type
• Web services / REST
• AJAX

Robotics

• MATLAB / Simulink / Real-Time Workshop
• Gentoo Linux (very bare-bones OS)
• Linux kernel / drivers
• Real-time OS concepts
• Serial port communications (yep... are we suddenly back in 1990 or what?)

... and not to mention, a heapload of proprietary technologies of my client(s).

I tell ya, I'm gonna deserve another degree for all this.

Installing LAMP

Linux
Gawd, where to even begin?

If you are fairly non-techie like myself (lol, this blog is deceptive!) I would strongly recommend you go with one of the following distros.
http://www.ubuntu.com
http://www.xandros.com


Apache
./configure --prefix=/usr/local/apache2
make
make install


MySQL
./configure --prefix=/usr/local/mysql
make
make install
groupadd mysql
useradd -g mysql mysql
cp support-files/my-medium.cnf /etc/my.cnf
cd /usr/local/mysql
bin/mysql_install_db --user=mysql
chown -R root .
chown -R mysql var
chgrp -R mysql .


PHP
./configure --prefix=/usr/local/php5 \
--with-apxs2=/usr/local/apache2/bin/apxs \
--with-mysqli=/usr/local/mysql/bin/mysql_config \
--enable-debug \
--enable-maintainer-zts
make
make install

Apache and MySQL at system startup

Here is what I had to do to get MySQL and Apache to startup automatically on a Ubuntu 6.06 Linux system...

MySQL
-----------------------------------------
References Used
-----------------------------------------
http://www.adobe.com/devnet/dreamweaver/articles/lamp.html
http://dev.mysql.com/doc/refman/5.0/en/automatic-start.html
http://dev.mysql.com/doc/refman/5.0/en/mysql-server.html
http://www.debian-administration.org/articles/28

-----------------------------------------
Changed in /etc/my.cnf (From MySQL site)
-----------------------------------------
[mysqld]
user=mysql

-----------------------------------------
Set startup item (From Dreamweaver site)
-----------------------------------------
# sudo cp /usr/local/mysql/share/mysql/mysql.server /etc/init.d/mysql
# sudo update-rc.d mysql defaults

Results of the update-rc.d command were as follows:
Adding system startup for /etc/init.d/mysql ...
/etc/rc0.d/K20mysql -> ../init.d/mysql
/etc/rc1.d/K20mysql -> ../init.d/mysql
/etc/rc6.d/K20mysql -> ../init.d/mysql
/etc/rc2.d/S20mysql -> ../init.d/mysql
/etc/rc3.d/S20mysql -> ../init.d/mysql
/etc/rc4.d/S20mysql -> ../init.d/mysql
/etc/rc5.d/S20mysql -> ../init.d/mysql


Apache
-----------------------------------------
References Used
-----------------------------------------
http://www.adobe.com/devnet/dreamweaver/articles/lamp.html

-----------------------------------------
From Dreamweaver site
-----------------------------------------
# sudo cp /usr/local/apache2/bin/apachectl /etc/init.d/apache
# sudo update-rc.d apache defaults

Results of the update-rc.d command were as follows:
Adding system startup for /etc/init.d/apache ...
/etc/rc0.d/K20apache -> ../init.d/apache
/etc/rc1.d/K20apache -> ../init.d/apache
/etc/rc6.d/K20apache -> ../init.d/apache
/etc/rc2.d/S20apache -> ../init.d/apache
/etc/rc3.d/S20apache -> ../init.d/apache
/etc/rc4.d/S20apache -> ../init.d/apache
/etc/rc5.d/S20apache -> ../init.d/apache

MySQL - Socket error

On my Linux box, MySQL had been working fine.

Then, just a few days ago out of the blue for no apparent reason I started getting the following error.

Can't connect to local MySQL server through socket '/tmp/mysql.sock'

Now, we can't really say it is for no reason, obviously something in my system had changed. I am always messing around with that OS, without really understanding it.

Anyway, I found some great info here.
http://security.linux.com/article.pl?sid=04/08/19/1422204&tid=73&tid=35

I will have to go through all the info there and understand and implement it, but for now I only did the following three lines worth.

chown -R root /usr/local/mysql
chown -R mysql /usr/local/mysql/var
chgrp -R mysql /usr/local/mysql

And it worked! Problem solved for now.