History
When Linus Torvalds was studying at the University of Helsinki, he was using a version of the UNIX operating system called ‘Minix’. Linus and other users sent requests for modifications and improvements to Minix’s creator, Andrew Tanenbaum, but he felt that they weren’t necessary. That’s when Linus decided to create his own operating system that would take into account users’ comments and suggestions for improvements.
In 1991, ideal conditions existed that would create Linux. In essence, Linus Torvalds had a kernel but no programs of his own, Richard Stallman and GNU had programs but no working kernel. Late in 1991, Linus Torvalds had his kernel and a few GNU programs wrapped around it so it would work well enough to show other people what he had done.
Distributions
The three most popular Desktop distributions of Linux are;
The four most popular Server versions of Linux are;
The Debian Project was founded by Ian Murdock in 1993. Debian gets its name from the combination of Ian Murdock and his wife Debra’s name (Deb-Ian) .Despite its not-for-profit status, Debian is an extremely versatile distribution. It forms the base of many user-friendly distributions like Ubuntu, Linspire and Xandros.
mv sources.list.old sources.list
CentOS (Linux.org runs on a CentOS Linux VPS)
install new software
- dpkg
- dselect
- rpm
- yum
File System
/
This will get you into the ‘root’ or main directory, not /root
root
root user’s home directory
home
directory that contains non-root user’s home directory
bin
bin/ is one of the most important directories in Linux. You’ll find all of the most used commands there. Right now you should be seeing a lot of red (or green, depending on your version of Linux). Those are programs.
sbin
This directory is like /bin in that it has frequently used programs in it, but they’re only meant to be used by root.
etc
This houses most of the configuration files for Linux.
dev
These are the devices that your system uses or can use.
boot
where the Linux kernel usually is.
tmp
/tmp is a directory that is used to store temporary files, as the name may suggest.
var
/var is a directory for certain files that may change their size (i.e. variable size) For example, there are a few excellent databases for Linux. One is called MySQL. Normally, MySQL keeps its data in a subdirectory of /var called /var/mysql/.
usr
unix system resources
containing dynamically combined programs, user files and manually-installed programs
The usr/ directory contains files and programs meant to be used by all of the users on the system.
lib
/lib is for library files. That’s where the name /lib comes from.
other directories
Most installations of Linux will also provide these directories:
/mnt /cdrom /floppy
These shouldn’t contain anything. Later on, we’ll explain in more detail what these are for. Let’s just say that in Linux, if you want to see what’s on a floppy disk or a CD, you’re not going to be able to just click on an ‘a:’ icon or a ’d:’ icon. You’re going to do
File Permission
Let’s look at what these symbols mean:
start with -(d for directories)
three entity types
- owner
- group
- world
permission symbol
- r:read 4
- w:write 2
- x:execute 1
File Backup
tar
an archiving utility
tar -cvf(create verbose file) tarname files
tar -czvf(create zip verbose file) tar.gzName files
’tar’ just assembles the files together into only one file. There is no reduction in the size of these files (the tarball might even be bigger!) Now we would have to do one more thing in order to reduce this file into a more manageable size: use ‘gzip’.
tar -zxvpf my_tar_file.tar.gz
-z - unzip the file first -x - extract the files from the tarball -v - "verbose" (i.e tar tells you what files it’s extracting) -p - preserves dates, permissions of the original files -f - use the file in question (if you don’t specify this, tar just sort of sits around doing nothing)
gzip
gzip tar_file.tar
the file extension becomes .tar.gz
Text Editor
vi
The most popular text editor for Linux is called ‘vi’. This is a program that comes from UNIX. There is a more recent version called ‘vim’ which means ‘vi improved’.
ESC + i start editing
ESC + :w save
ESC + ：wq save and quit
ESC + :q quit without saving
ESC + :q! quit without saving and warning
joe
Ctrl+k+h
pico
…
User
adduser
create a new user or update default new user information
userdel
delete a user
passwd
change user password
Package
slackware
installpkg file.tgz
removepkg file.tgz
upgradepkg file.tgz
debian
dpkg file.deb
(advanced package tool)
apt-setup
apt-get update
apt-get install package.deb
apt-get remove package.deb
apt-get upgrade [p]
Commands
shutdown
shutdown -h(halt) now
shutdown -r(reboot) now
shutdown -r now
shutdown -h +5 (5 minutes)
man
This command will show the manual for a command or program. The manual is a file that shows you how to use the command and list the different options for the command in question.
man mkdir
info
Typing info [command name] will get you more information on a command and is more current than most man files and perhaps a little more readable. In fact, some ‘man’ files will actually tell you to consult the ‘info’ file. The ‘info’ files are not always installed automatically. so you may want to consult your own version of Linux about these files.
whatis
display one-line manual page descriptions
apropos
search the manual page names and descriptions
chmod
Change access permissions
chmod 644 myDoc.txt
chown
Change file owner and group
chown owner.group filename
chown bob.bob example.txt
last
show a listing of last logged in users
df
report file system disk space usage
free
Display amount of free and used memory in the system
du
du -b filename
ps
report a snapshot of the current processes
kill
kill PID
kill a process
mkdir
make directories
rmdir
remove empty directories
rm
remove files or directories
mv
move or rename files
mv tonyd/(dir) my_friends/(dir)
cp
copy files and directories
touch
change file timestamps
find
search for files
grep
prints lines that contain a match for one or more patterns
who
prints information about users who are currently logged on.
tee
read from standard input and write to standard output and files
> does the same without |
ls -l | tee directory_listing
date > directory_listing
date >> directory_listing(append)
whereis
locate the binary,source, and manual page files for a command
which
locate a command
echo
display a line of text
wc
print newline, word, and byte counts for each file
dir
list directory contents
pwd
print working directory
cal
displays a calendar and the adte of Easter
<TAB>
auto complete
up arrow
show last command
down arrw
most recent commands