Linux for beginners

Hello guys, I am a truely Linux lover . While learning Linux for first time I found many difficulties. There are 
a lots of commands associated with every single task. Even many of them require me to input many command 
line arguments, otherwise they'll not work and show me error. For every command to work I used to need to look 
after the help and things got to be messed up to me. ...after a rigorous work, finally I learned them and 've found 
that they are amazing. Every single command and command line programs have tremendous power themselves. 
So, I've decided to help you to learn the basics of linux if are a novice to linux world, but love it truely.

Installation and basics idea about Linux:
I'll guide you to installing Linux in your computer. I prefer to work on Red Hat release and Mandrake Linux release. 
If you are a desktop user then Mandrake Linux is best suited for you. Though I am not telling you that other Linux distributions are not good. Some best distributions are 

1. SUSE Linux release
2. RedHat Linux release
3. Mandrake Linux release
4. Open Linux(from Caldera)
5. Debian Linux

Before installation, first make sure what type of hard-disk you have-

1. is it SCSI or not ?
2. is it 10.2 or higher ?
In case of SCSI, when the installation wizard asks you, you should check the box that you have SCSI disk, 
otherwise uncheck it. First make a partition free for Linux. This can be best done using Windows's "fdisk" tool.
If you have Windows as your primary O.S. then go to MSDOS prompt and issue the command "fdisk"(without " "). 
Then a menu will appear. Choose "delete logical drive" and accordingly delete the logical dos drive 
(say D or E or...) you want to accomadate for Linux. It'll be best to delete only the last logical dos drive. 
Before doing this, backup the drive if you've important files and free that. For Linux, giving a partition of 
around 1 GB to 3 GB is sufficient. Refer to the manual of you Linux. Then reboot it. Yah...you're done. 
Boot your computer using the CD1 and after some time you'll be presented with the graphical installation 
wizard. For Linux partion choose a swap drive ( used by Linux for data swapping with RAM ). For better result 
the swap partition should've
size = 2 x ( size of your RAM ) + 25 Mb. Make a /boot partition if you've hard-disk of size greater than 10, also 
this'll give you better result in case of RedHat Linux. Otherwise it may happen that the boot partition may fall 
outside the 1024 cylinder area of the disk. The /boot should have size equals to 16 to 20 Mb of Ext2 type. 
Then go ahead and create all other partions. Suggested configuration-

SWAP = 2 x (size of RAM) + 25 Mb
/boot = 16 to 20 Mb

/ = rest of the free space Install LILO as your boot loader as it is good enough to handle multiple O.S in MBR
( if any option there). If you want to experience the graphical power of Linux then choose either KDE or GNOME 
or both as the window managers. You'll be prompted to enter the root's passwd-know that root is the main user 
who've all the power of Linux. Working as root is also dangerous as you can destroy system files. So, for desktop 
user, I advise you to chose another general user and always login through this user. It'll be safe for both you and 
your computer. OK then...relux, while it is being installed. 

Help is always at your hand :
 

In Linux HELP is always at your hand...only problem is that you have to find it yourself. I'll assume you that are in  text mode or you have opened a shell window ( just like MSDOS shell ) in graphical mode. In linux you can learn  about any command or program using this command  > "command name" --help or > "command name" -h This'll produce a list of available options( switches) to you and a detailed descriptions. You can learn about  any command or program by using the "man" command or "info" command. Linux reserves the manuals of  any program or command. You can read this manual with the "man" or "info" command. For e.g. issue the command at the terminal window as >man "command name" or >info "command name" After reading you can terminate man or info by pressing the "Q" button of your keyboard. Most of the Linux programs  can be quited by pressing the "Q" button.  Some types of manuals are given below to help you learn more /usr/man/man1-various commands /usr/man/man2-system calls-documentation for kernel functions and system calls /usr/man/man3-Library calls /usr/man/man4-Information about the files in /dev /usr/man/man5-various file formats /usr/man/man6-The Linux Games /usr/man/man7-Description of linux file systems /usr/man/man8-Administrations /usr/man/man9- kernel's modules Lern how to navigate directory: In linux directory nevigation is very easy. Just like DOS you can use the "cd"(change directory)command to simply  move between directories. The main directory tree structure of Linux, you'll see is as follows   / |--/bin(contains all the main commands execution files) |--/etc(this dir is used by system administrator as it contains system adminis. files) |--/dev(contains device related files) |--/opt |--/home(Your home where you'll save most of your files and documents, like Windows's "My Documents") |--/mnt(used for input/output to cdrom, floppy, zip drive, Windows's partitions and others) |--/tmp(temporary directory used for keeping temp. files) |--/root(root's dir) |--/var |--/sbin(some programs and additional commands) |--/usr(user's software and their documentations) In some system it could differ. Directory nevigation is basically done by cd as I told you earlier. The basic command is >cd /usr/bin --will move you to bin directory in /usr. For mooving to the root directory from anywhere the command is >cd / For moving to the home dir from anywhere the command is >cd   ~(tilde sign) For moving up one dir >cd ..(two dots preceeding space) The command "pwd" is used to print the current working directory. In Linux everything is treated as files,  even directory or devices too. So you have learnt how to move around between directories. Please move to next page  Finding something: Now after some time you'll be able to find some specific files. Let's start. To find any file issue this command > find "dir name where to find" -name "file name" -print. For example to  find the file inittab in /etc dir I can issue the command >find /etc -name inittab -print. This'll search the /etc directory and list it. To find a rescently created/modified file the option -atime is used as >find / -type f -atime +10 -print. This'll find the  file that was created in the last 10 days ago. >find / -type f -mtime (no. of days) -print will print that file that was  modified. Wildcard chars. can be used for searching files. The command >find /home -name *.jpg -print will search for the  jpeg pic. files. If yo want to where a particular file is located use "whereis" as >whereis (command name say "cd"). If can not remmember a particular command or want to know some apropriate command for a particular task  then use "apropos" command. For example, >apropos text editor --will print all the available text editor in your system. Reading files: (1) "ls" command is used for listing the files or directories in the current directories. The option -l will give you the long listing format,i.e, the r(read)w(write)x(execute) permissions, date of creation etc. For listing specific files use as >ls *.jpg. (2) "dir" can similarly be used as used in DOS. "vdir" is similar to >ls -l. (3)"cat" command is used for displaying contains of a files to screen.E.g. >cat (file name say myfile.txt) will print the contents of a file to screen. >cat -n myfile.txt will associate line no. (4)For suitable reading you can use the "more" command as similar to DOS's more command. E.g. >cat myfile.txt | more will help you to read suitably if the contents of myfile.txt doesn't fit to screen. You have to press enter key for moving. (5)"less" is very usefull for reading purpose. You can move upward or downward using the arrow keys.  E.g. >less myfile.txt.  Creating files:- (1)The "cat" command can be used to create a short text files without running any text editor.The syntax is >cat > myfile.txt --this'll prompt you to write something texts. After you've finished press Ctrl+D to save and close the file. The redirection operator ( >) can be used to combine files.E.g. >cat *.txt > new.txt --will combine all *.txt files to new.txt file. For appending >> is used as >cat 1.txt >> 2.txt -- contents of 1.txt will be appended to 2.txt file. (2)The "touch" command is used to create 0 bite file or modifying the time of creation of an existing file.  Creating directories:- Directory creation is very easy in Linux. Issue the command to create a single directory >mkdir /home/temp --this'll create a new directory temp under home. You cann't create a directory under a one that doesn't exist.For e.g., say, suvo dir. is not present and I try to create a dir temp_239 under it, then this command >mkdir suvo/temp_239 will show an error. Better try in this case the -p switch as >mkdir -p suvo/temp_239.  Removing files:- Files can be removed using "rm" command. >rm temp1_file, > rm tempFile1 tempFile2.  ****REMEMBER ALWAYS, LINUX IS VERY CASE SENSITIVE TO FILE NAME****          You cann't delete a file which don't have enough permission, i.e., if the file is created by other user or root and it is not granted by him/her to delete. Other options with "rm" are:   -i = interactive, -f = forcing to delete.  Removing directories:- Use "rmdir" as >rmdir suvo/temp_239(assuming temp_239 is empty), you can recursively delete the files as well as the directory using -r option. Also to remove the parent dir with the child use -p option. "rm" can also be used with -d(or --directory) option to delete a dir. Renaming and moving files or directories:- Very easy. Use mv to rename a file or dir. or to move to another place( just like cut and paste ) as >mv suvo raj --rename suvo(either file or dir) to raj >mv raj /opt --move raj to /opt Installing software: In Linux the various softwares can be any of the following formats A. compressed format *.tar *.tar.gz *.bz2 *.Z *.zip B. RPM format(*.rpm) For *.tar file use >tar -xvfw abc.tar ( -x = extract, -v = verbose, -f = file, -w = interactively). For *.tar.gz use >tar -zxvfw abc.tar.gz ( -z passes through "gzip" program). For *.bz2 use >bzip2 -d(--decompress) abc.bz2 For *.Z use >uncompress abc.Z After compressing you may find some file in the dir as "README" or "INSTALL" or like that. Read the file using "less" to perform other operations as directed there to complete the software installation. Sometimes you will be instructed to run some script( similar to batch file *.bat in DOS). RPM means RedHat Package Manager - this is invented by RedHat to distribute software in an easy way. RPM takes care of all the installation process. You need n't be wooried. In this case use >rpm -ivh filename.rpm( -i = install, -v = verbose, -h = prints hash char(#) as progress bar). To uninstall use rpm -evh filename.rpm ( -e = erase ). To perform quary use rpm -q filename.rpm( this'll tell you if the s/w is installed or not ) This is the end of the tutorial but not the last. I am going to prepare other new tutorials on "how to write linux shell script" and "how to develop C\C++ program in Linux" if you encourage me to do so. Ok, the miscelenaous commands those can not be grouped together in a category are described below.  (1)"cp" is used for copying files and directories to other places without replacing the original. (2)"mount" is used for mounting some file system on devices( such as floppy, cdrom, zip drive, Windows drives etc). You must use "umount" to unmont that system. (3)"chmod" is used to change the read+write+execution permission of a file or directory. (4)"date" is used to change the current date of the Linux system. (5)"time" is used to change the current time of the Linux system. (6)"umask" is used to change the default r+w+x system. (7)"mc"(midnight commander) is basically a shell(command interpreter), but it offers a nice directory navigating structure. (8)"echo" command is used to output something on the screen. (9)"ps" command is used to list all the processes those are currently running and to get their Process ID(PID) number. (10)"kill" is used to terminate a running process. (11)"mail" is used to send mail to other user. (12)"su"(super user)changes the general user to login as root. (13)For shutting down the system use "/sbin/shutdown -h now"(before doing this you have to use "su" if you are in general user mode). (14)For rebooting down the system use "/sbin/shutdown -r now"(before doing this you have to use "su" if you are in general user mode).  Some quick notes:- 1.Suppose you have a CD containing a software "myswr2.7.8.i386.rpm" and you want to install it in your computer. What steps should you do- $cd /home $su(this'll prompt you to enter the root's password) $mount /mnt/cdrom (if no error)$cd /mnt/cdrom/"software directory" $ls -l *.rpm(check to see if it is present or not) $cp myswr2.7.*.rpm /tmp $rpm -q myswr(this'll check if myswr is installed or not) (if not installed)$cd /tmp $rpm -ivh myswr*.rpm umount /mnt/cdrom $eject(it'll eject the CD from the cd-tray $myswr --help myswr -a -b -c "...." &(to run in the background & operator is used with program) 2.Suppose a program got hanged, then follow the steps as mentioned: $cd /home $ps(get the PID of the hanged process) $kill "PID no" This'll solve your problem.