Contents of linux

Install and configure uninstall Commands samples

Introduction to linux

This language was especially developed for creating the UNIX system. Using this new technique, it was much easier to develop an operating system that could run on many different types of hardware.

Linux can be downloaded in its entirety from the Internet completely for free. No registration fees, no costs per user, free updates, and freely available source code in case you want to change the behavior of your system.

LinusTorvalds, a young man studying computer science at the university of Helsinki, thought it would be a good idea to have some sort of freely available academic version of UNIX, and promptly started to code

installationInstallation Overview:

It's wise to collect configuration information on your hardware before installing. Know the vendor and model number of each card in your machine; collect the IRQs and DMA channel numbers. You probably won't need this information -- but if it turns out you do, you'll need it very badly.

If you want to run a "dual-boot" system (Linux and DOS or Windows or both), rearrange (repartition) your disk to make room for Linux. If you're wise, you'll back up everything first!.

The easy way: If you have an EIDE/ATAPI CDROM (normal these days), check your

machine's BIOS settings to see if it has the capability to boot from CD-ROM. Most machines made after mid-1997 can do this.

If yours is among them, change the settings so that the CD-ROM is checked first. This is often in a 'BIOS FEATURES' submenu of the BIOS configuration menus.

Then insert the installation CD-ROM. Reboot. You're started.If you have a SCSI CDROM you can often still boot from it, but it gets a little more motherboard/BIOS dependent. Those who know enough to spend the extra dollars on a SCSI CDROM drive probably know enough to figure it out.

The Hard Way Make installation floppies. Boot an installation mini-Linux from the floppies in order to get access

to the CD-ROM.

First installation step

Installation Overview

First Installation Steps: The Easy Way If you have an EIDE/ATAPI CDROM (normal these days),

check your machine's BIOS settings to see if it has the capability to boot from CD-ROM. Most machines made after mid-1997 can do this.

If yours is among them, change the settings so that the CD-ROM is checked first. This is often in a 'BIOS FEATURES' submenu of the BIOS configuration menus.

Then insert the installation CD-ROM. Reboot. You're started.

Basic parts of an istallation kit Here are the basic parts of an installable distribution:

The README and FAQ files. These will usually be located in the top-level directory of your CD-ROM and be readable once the CD-ROM has been mounted under Linux. (Depending on how the CD-ROM was generated, they may even be visible under DOS/Windows.) It is a good idea to read these files as soon as you have access to them, to become aware of important updates or changes.

A number of bootdisk images (often in a subdirectory). If your CD-ROM is not bootable, one of these is the file that you will write to a floppy to create the boot disk. You'll select one of the above bootdisk images, depending on the type of hardware that you have in your system.Basic Parts of an Installation Kit

Getting prepared for installation First, collect any manuals you have on your hardware -- motherboard, video

card, monitor, modem, etc. -- and put them within easy reach.

Second, gather detailed information on your hardware configuration. One easy way to do this, if you're running MS-DOS 5.0, or up, is to print a report from the Microsoft diagnostic utility msd.exe (you can leave out the TSR, driver, memory-map, environment-strings and OS-version parts). Among other things, this will guarantee you full and correct information on your video card and mouse type, which will be helpful in configuring X later on.

Third, check your machine for configuration problems with supported hardware that could cause an un-recoverable lockup during Linux installation.

It is possible for a DOS/Windows system using IDE hard drives andCD ROM to be functional even with the master/slave jumpers on the drives incorrectly set. Linux won't fly this way. If in doubt, check your master-slave jumpers!

Configuration of linuxThe default Ubuntu configuration is easy enough to use for most

users. If you use your computer more than most, you will inevitably want to configure Ubuntu to suit your tastes.

If you have never used GNOME, you will want to learn the parts of the Ubuntu desktop. The top left of the desktop includes the menu bar, the centre of almost all configuration options. The other parts of the desktop are also explained on pages dealing with the top right and the bottom of the Ubuntu desktop.

Unless you are perfectly content with the software that comes with Ubuntu, you will want to install more at some point. Most guides on

the Internet tell you how to use "sudo apt-get" and other special incantations to install software. Ubuntu, however, comes with its own software installer called Synaptic. You can learn how to use it under "Adding Ubuntu Software and other linux software to ubuntu.

To help you further, you can enable Ubuntu to install software from more repositories than those that come as standard. By adding repositories, you can install non-official Ubuntu software. Further, you can scrap everything that comes with Ubuntu and install your own, customised repository list.Configure Ubuntu

Create directories

mkdir - make directories

usage:

mkdir [OPTION] DIRECTORY Options: Create the DIRECTORY(ies), if they do not already

exist. Mandatory arguments to long options are

mandatory for short options too. -m, mode=MODE set permission mode (as in

chmod), not rwxrwxrwx - umask

-p, parents no error if existing, make parent directories as needed

-v, verbose print a message for each created directory

-help display this help and exit -version output version information and exit

To change directories

cd -to change directories Use cd to change directories. Type cd followed by

the name of a directory to access that directory.Keep in mind that you are always in a directory and can navigate to directories hierarchically above or below.

Move directories

mv- change the name of a directory Type mv followed by the current name of a

directory and the new name of the directory. Ex: mv testdir newnamedir

Present working directories

pwd - print working directory will show you the full path to the directory

you are currently in. This is very handy to use, especially when performing some of the other commands on this page.

Remove directories

rmdir - Remove an existing directory rm -r Removes directories and files within the

directories recursively.

To change file owner and group

chown - change file owner and group Usage: chown [OPTION] OWNER[:[GROUP]] FILE chown [OPTION] :GROUP FILE chown [OPTION] --reference=RFILE FILE

Options: Change the owner and/or group of each FILE to

OWNER and/or GROUP. With --reference, change the owner and group of each FILE to those of RFILE.

-c, changes like verbose but report only when a change is made

-L traverse every symbolic link to a directory encountered

-P do not traverse any symbolic links (default)

-dereference affect the referent of each symbolic link, rather than the symbolic link itself -h, no-dereference affect each symbolic link instead of any referenced file (useful only on

systems that can change the ownership of a symlink) -from=CURRENT_OWNER:CURRENT_GROUP change the owner and/or group of each file only if its current owner and/or group match those

specified here. Either may be omitted, in which case a match is not required for the omitted attribute.

-no-preserve-root do not treat `/' specially (the default) -preserve-root fail to operate recursively on `/' -f, -silent, -quiet suppress most error messages -reference=RFILE use RFILE's owner and group rather than the specifying

OWNER:GROUP values -R, -recursive operate on files and directories recursively -v, -verbose output a diagnostic for every file processed

The following options modify how a hierarch

The following options modify how a hierarchy The following options modify how a hierarchy is traversed when the -R option is

also specified. If more than one is specified, only the final one takes effect. -H if a command line argument is a symbolic link to a directory, traverse it

-L traverse every symbolic link to a directory encountered -P do not traverse any symbolic links (default)

Change file access permissions chmod - change file access permissions

Usage: chmod [-r] permissions filenames r Change the permission on files that are in the

subdirectories of the directory that you are currently in. permission Specifies the rights that are being granted. Below is the different rights that you can grant in an alpha numeric format.filenames File or directory that you are associating the rights with Permissions

o - Other. a - All. r - Read the file. w - Write or edit the file. x - Execute or run the file as a program.

Short listing of directory contents ls - Short listing of directory contents -a list hidden files -d list the name of the current directory -F show directories with a trailing '/' executable files with a trailing '*' -g show group ownership of file in long listing -i print the inode number of each file -l long listing giving details about files and

directories -R list all subdirectories encountered -t sort by time modified instead of nam

Copy file command cp - Copy files cp myfile yourfile Copy the files "myfile" to the file "yourfile" in the

current working directory. This command will create the file "yourfile" if it doesn't exist. It will normally overwrite it without warning if it exists.

cp -i myfile yourfile With the "-i" option, if the file "yourfile" exists, you

will be prompted before it is overwritten. cp -i /data/myfile

Copy the file "/data/myfile" to the current working directory and name it "myfile". Prompt before overwriting the file.

cp -dpr srcdir destdir Copy all files from the directory "srcdir" to the directory "destdir" preserving links

(-poption), file attributes (-p option), and copy recursively (-r option). With these options, a directory and all it contents can be copied to another dir

Cat command cat - Sends file contents to standard output. This is

a way to list the contents of short files to the screen. It works well with piping.

To display calendar: cal month year - Prints a calendar for the specified

month of the specified year. To print contents of specified files: cat files - Prints the contents of the specified files.

Clear and compare between two files clear - Clears the terminal screen. cmp file1 file2 - Compares two files, reporting all

discrepancies. Similar to the diff command, though the output format differs.

diff file1 file2 - Compares two files, reporting all discrepancies. Similar to the cmp command, though the output format differs.

Extra commands To check sum: cksum [man page] - checksum and count the

bytes in a file cp [man page] - copy files and directories To display date: date [man page] - print or set the system date and

time dd [man page] - convert and copy a file du [man page] - estimate file space usage

fgrep [man page] - print lines matching a pattern find [man page] - search for files in a directory hierarchy fold [man page] - wrap each input line to fit in specified width G- grep [man page] - print lines matching a pattern

echo: Display message on screen, writes each given

STRING to standard output, with a space between each and a newline after the last one.

Syntax: echo [options]... [string]... exit:

Exit from a program, shell or log out of a Unix network.

Syntax:

exit

Join: Join lines on a common field, writes to standard

output a line for each pair of input lines that have identical join fields.

SYNTAX: join [Options]... File1 File2

open: Open a file in its default application. Syntax:

open Files...

passwd: Modify a user password.

SYNTAX

passwd [options...]

OPTIONS -d, --delete delete the password for the

named account (root only)

-f, --force force operation (effectively calls `chfn'?)

-k, --keep-tokens keep non-expired authentication tokens

-l, --lock lock the named account (root only)

-S, --status report password status on the named account (root only) --stdin read new tokens from stdin (root only) -u, --unlock unlock the named account (root only) -?, --help Show this help message --usage Display brief usage message

How to uninstall linux

Unstalling an operating system usually means leaving your system unbootable.

Operating system will not work without their boot files or if they are never called by the boot loader.

therefore,to remove the presence of an operating system,it is enough to dereference it from the boot loader menu.

Alternatively, you can also delete its files or replace them with another operating system.