The Linux kernel is the core of the Linux operating system. To find out
which version of the Linux kernel you are running, simply type
uname -r in a terminal. For more information on the
Linux kernel, please visit
http://www.kernel.org. For information on how to install or compile the
Linux Kernel, please see our
Kernel Compile/Upgrade
Guide.
One of the pleasures of running linux is choice. The choice of which Linux
Distribution you wish to run is 100% up to you. You can browse our
Distributions Page for
comparisons of the various distributions out there. If you are totally new
to linux we suggest you start off with either
Red Hat Linux or
Mandrake Linux as they are
easier to install, configure and maintain.
The root user is the master user or systems adminstrator of the machine. The
root user has full access to all files and directories, which is why you
will only want to use the root account to perform system maintainance or to
install applications.
In order to reboot your machine, you must instruct the Linux
kernel to stop all
the processes (programs) it's currently running. Do not simply press the
reboot button on the front of your computer case, as Linux must be properly
shut down/restarted. To restart your machine, as root, run either of the
following commands in a terminal:
reboot
shutdown -r now
On most systems you can also press (all at once) the control, alt and delete
keys.
In order to shut down your machine, you must instruct the Linux
kernel to stop all
the processes (programs) it's currently running. Do not simply press the
power off button on the front of your computer case, as Linux must be
properly shut down/restarted. To shut down your machine, as root, run either
of the following commands in a terminal:
halt
shutdown -h now
If you want to remove the Lilo or Grub boot loader from your system (if you
are uninstalling linux etc) follow the procedures below:
For Windows 95/98 etc:
Use a dos boot disk and at the command prompt type:
fdisk /mbr
For Windows XP:
Boot off the XP Installation CD and go into rescue mode. From there run the
command:
fixmbr
While logged in as root, type adduser username at the
shell prompt, replacing username with the name you want to use to log
in. You can create as many users as you wish, one for each member of your
family, for example.
While logged in as root, type userdel username at the
shell prompt, replacing username with the user name you wish to
delete.
To set the password for a specific user, type (while logged in as root)
passwd username at the shell prompt, replacing
username with the name of the person who's password you wish to change.
By typing just passwd you'll be able to change the
password of the user under who's name you're currently logged in as. Do not
use passwords which are easy to guess, like your middle name or your pets
name.
cd - Used to change directories
Usage: cd [directory]
Example: cd /home/joey/html
Example: cd ../ (to move back one directory)
Example: cd (to return to your home directory)
For more information, in a terminal, type man cd
cp - Used to copy files/directories from one location to another
Usage: cp file newlocation
Example: cp /home/joey/index.html /var/www/index.html
Example: cp /home/joey/* /var/www/ (this will copy
everything in /home/joey to /var/www/)
For more information, in a terminal, type man cp
mv - Used to move or rename files
Usage: mv file location (to move)
Usage: mv filename newfilename (to rename)
Example: mv index.html /var/www/index.html (to move)
Example: mv index.html index2.html (rename)
For more information, in a terminal, type man mv
mv - Used to move or rename files
Usage: mv file location (to move)
Usage: mv filename newfilename (to rename)
Example: mv index.html /var/www/index.html (to move)
Example: mv index.html index2.html (rename)
For more information, in a terminal, type man mv
The default editor that ships with almost every distribution of Linux is
Vi. This editor is
slightly advanced and confuses most newbies. We suggest starting off with
Pico, a more simple editor. Pico is part of the Pine software package which
can be downloaded at
http://www.washington.edu/pine (It might already be installed on your
system). To edit a file with pico, simply run:
pico filename
This will open up the file and allow to you edit it. At the bottom of the
screen you will notice the various commands that you have access to with
Pico. If you wish to save the file and exit, simply hold down the control
key and hit the x key on your keyboard.
ls - To list the contents of a directory
Usage: ls [flags] directory
Example: ls (To list the current directory)
Example: ls /home/joey (To list the contents of
/home/joey)
Example: ls -a (To list hidden files)
Example: ls -l (To list file/directory permissions
and file sizes)
Example: ls -al /home/joey (To list all files and
permissions in /home/joey)
For more information, in a terminal, type man ls
To delete a file you must first have write permission to it. For information
about permissions, click
here. Once you have write permission, in a terminal run:
rm filename
There is no "Recycle Bin" in Linux so once you delete a file, it's gone for
good.
When removing files, you may use an astrix (*) as a wildcard flag to remove
certain files, for example if I wanted to remove all files that began with
the letter j, I would run rm j*
If anyone tells you to run rm -rf / as root, DO NOT
LISTEN TO THEM. Running this command will delete all the files/directories
on your Linux system.
If you have ownership to the directory and the directory is empty, you can
simply type rmdir directoryname to remove the
directory. If the directory is not empty and you wish to simply delete it
and all its contents, run rm -rf directoryname
Please be careful with the -rf flag, as it will remove everything in the
specified directory including sub directories. With root access and the rm
-rf command you can wipe out your entire system if you make an error.
Linux requires you to mount your cdrom/floppy drives when you wish to use
them. On most Linux distributions, the mount command will require root
access. Depending on which Linux distribution you run, one of the following
commands should mount your cdrom drive. As root, run:
mount /dev/cdrom /mnt/cdrom
mount /dev/cdrom /cdrom
Linux requires you to mount your cdrom/floppy drives when you wish to use
them. On most Linux distributions, the mount command will require root
access. Depending on which Linux distribution you run, one of the following
commands should mount your floppy drive. As root, run:
mount /dev/fd0 /mnt/floppy
mount /dev/fd0 /floppy
One of the great features of Linux is that it is a multi-user system. With
multi-users, it allows certain users to own files and directories so nobody
else can access/modify them, for example your /home directory. To change the
ownership of a file/directory, as root execute the following command in a
terminal:
chown username. filename/directory
This will change the ownership and group ownership of the specified file or
directory to the specified user. For more information, in a terminal, type
man chown
There are 3 different attributes a file can have that make up the
permissions for the file.
There is read access that allows users to read the file.
There is write access that allows users to modify the file.
There is executable access that allows users to execute the file.
From these three attributes, you now have three different levels of permissions, the first being for the owner of the file, the second being for the group the file belongs to and the third being all other users on the system.
To view the current permissions on files and directories run
the following command:
ls -l and you should see something that looks like:
drwxrwxr-x 3 joey html 4096 Sep 12 2000 images/ -rw-rw-r-- 1 joey html 267 Aug 8 12:55 index.shtml
The above shows you that images is a directory (d) and that
the owner and group (joey html) have read (r), write (w) and execute (x)
permissions while other users on the system only have read (r) and execute
(x) permissions.
For the index.shtml file, it shows joey and html as the owner and group and
they both have read and write access to the file. It also shows that other
users on the system only have read access. Note there is no executable
permission since the file is not an executable.
To modify the permissions on a file, you either have to own
it or be logged in as root. To modify the permissions, in a terminal type:
chmod xxx filename/directory
You will have to replace the xxx flags with the permissions you wish to
change. You can either go by the numerical value or by the actuals.
Some common numerical values are:
755 - Read, Write, Execute for owner, read, execute for group and other.
644 - Read, Write for owner, read for group and other.
666 - Read, Write for all.
700 - Read, Write, Execute for owner, nothing for group, other.
So if you wanted to make a file an executable for your user and other users
on the system, you would run the following:
chmod 755 somefile
For more information, in a terminal, type man chmod
There are two methods to search for files on your Linux machine, one method
being the locate command and the other being the find command. If you wish
to use the locate command, you must first update the locate database by
running the following command in a terminal as root:
/usr/bin/updatedb
This will create an index of all the files and their locations on your hard
drive. Once updatedb has completed running, you may now search your drive
for a specific file by running the following command in a terminal:
/usr/bin/locate filename
Another way to search your linux system is with the find
command. To find a file on your sytem with the find command, in a terminal
run the follwoing:
/usr/bin/find / -name filename Be sure to replace
"filename" with the actual name of the file.
To extract .tar.gz or .tgz files, run the following command in a terminal:
tar -zxvf file.tar.gz (or file.tgz)
This will normally create a new directory based on the filename. If you want
to extract a filename called file.tar (without the .gz) simply run:
tar -xvf file.tar
For more information, in a terminal, type man tar
To extract .bz2 files, run the following command in a terminal:
bunzip2 -dv file.bz2
This will normally create a new directory based on the filename. For more
information, in a terminal, type man buznip2
There are many ways to install applications in Linux. If the file you wish
to install is in .rpm format and you are running an RPM based distribution
such as Red Hat,
Mandrake or
SuSE, run the following command as root in
a shell prompt/terminal:
rpm -Uvh filename.rpm
If you are running Debian
GNU/Linux and you wish to install a .deb file, you can do so by running
the following command in a terminal as root:
dpkg -i filename.deb or apt-get
install package (if you have APT already installed/configured).
If the file you with to install is in a .tar.gz, .tgz or .bz2 format, you will first have to decompress (unzip) the file. Once the file has been unziped, it should create a directory based on the filename. Simply change into that directory and open up the README or INSTALL file in a text editor and follow the installation instructions.
To run a program, you must first make sure it has executable permissions
set. For more information on permissions, see
How do I view/change
permissions on files/directories? above. Once the file has executable
permissions, simply run the filename from a terminal. I will use the
filename "irc" as an example
Example: /usr/bin/irc (from anywhere on the system)
Example: ./irc (from the /usr/bin directory)