View source for Linux Spoken Tutorial/Basic Level Tutorial Set/Linux-part1

Spoken tutorial on basic linux commands part – 1



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| style="border-top:0.035cm solid #000000;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| <center>'''Visual Cue'''</center>
| style="border:0.035cm solid #000000;padding:0.097cm;"| <center>'''Narration'''</center>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Show slide number 1
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Dear friends, 

welcome to first part of spoken tutorial on basic linux commands.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 2
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>Before we start learning any command, let us have a look on a command to provide help on other commands. <pause> To find help on any linux you can use a command called </nowiki>'''man.'''

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type


man cp
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To find help on a linux command cp, let us type '''man cp.'''<nowiki><pause> What you see is the manual of the cp command. You can use up arrow and down from arrow to navigate through the manual. </nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and press '''q'''
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To exit from the manual, you have to press '''q''' key.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 3
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Most linux commands have a built in –help switch. This provides a short help on the given command and lists all the options available for the given command.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type


cp –help
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| As you can see, --help lists all the options available for copy command and how to use cpy command.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 4
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Our first linux command for this tutorial is '''cp. '''This command copies files or directories from one location to another.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type


cp abc.txt temp
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To copy abc.txt to temp directory type cp space abc.txt space temp. Simple and you are done copying the file from one location to other.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type


cp -r temp perm
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Cp by default will not copy directories. To copy a directory you have to use the option '''-r '''<nowiki>. <pause> to copy temp directory </nowiki>to perm directory, type cp space minus r space temp space perm. Here '''temp''' is known as source and '''perm''' is known as destination.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 5
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Our next command is for moving files from one location to anothher. The command to move a file, the command is '''mv'''.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type


mv xyz.txt perm 
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| To move a file from current directory to perm directory, type mv space xyz.txt space perm .

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type


mv first.txt second.txt
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Mv command can also be used to rename files and directories. To rename fisrt.txt to second.txt, type mv spave first.txt space second.txt. Thats all and the file is renamed.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 6
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>Our next command will help us list all files and sub-directories in a given directory.<pause> This command is called </nowiki>'''ls'''.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type


ls
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| When you type ls in the console, a list of all files and directories is shown. Based on the configuration of the console, directories and some files may be shown in different color.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type 


ls -a
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>Ls doesnot list hidden files by default. To list hidden files type ls witth -a option.<pause> As you can see hidden files and directories, starting with a dot are now listed </nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type 


ls -l
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Ls can list more information about files along with listing. When combined with '''-l '''<nowiki>option the ls commandd will show you the filename, permissions, owner user, owner group, size and date of modification. <highlight each attribute in console as it is spoken></nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type 


ls -lh
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| The long listing generated by ls -l option shows file size in bytes. This will require you to convert the the bytes to megabytes or gigabytes to have an idea of how much space is being used by a file.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 7
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Now let us look at a command that will allow us to change directories. The command is called '''cd '''.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console and type


cd dummy
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>To switch to directory called dummy type cd space dummy. Notice the prompt in the console shows the new directory name. <highlight the changed directory name in the console></nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 8
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Last command that we will learn in this tutorial is '''ln '''<nowiki>. This command is used to create links to files or directories.<pause></nowiki>

<nowiki>Unix systems support two types of links.<pause> hard links and symbolic links.</nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay with the slide
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Symbolic links are also known as soft links. When you create a symbolic link, a special file is created that refers to another file. A symbolic link can exist independent of the original file.If the target file is deleted or moved, symbolic link still exists but it points to a file that does not exist.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay with the slide
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Hard links are special files too but if you remove the original file, the data can still be accessed through the hard link.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to console
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Let us look at few examples to understand thsi better.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in console and type


ln -s original.txt symb.txt
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>Let us create a symbolic link. To create a symbolic link type ln -s original.txt symb.txt. <pause> This will create the symbolic link.</nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type


ln original.txt hard.txt
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Let us now create a hard link. To create a hard link type ln original.txt hard.txt . This will create a hard link

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type


ls -l
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>On long listing the files in a directory, we can see that soflink is represented differntly and points to the original file location <highlight the link as you speak it>. <pause> You will notice that hard link is shown as a normal file.</nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type


rm -f original.txt

ls -l
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Now, if we remove the original file and do a listing, you will notice that symbolic link has a red marking. This is because the original file pointedd by the symbolic link, soesnot exist any more.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type


cat symb.txt
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| <nowiki>If we try to open symb.txt by typing cat symb.txt , we get an error. <hightlight the error in the console></nowiki>

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Stay in the console and type


cat hard.txt
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| Lets now open hard,.txt by typing cat hard.txt . We notice that data of the original.txt is still available in the hard link.

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| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:none;padding:0.097cm;"| Switch to slide number 9
| style="border-top:none;border-bottom:0.035cm solid #000000;border-left:0.035cm solid #000000;border-right:0.035cm solid #000000;padding:0.097cm;"| This brings us to the end of the first part of spoken tutorial on basic linux commands. Thanks for watching this tutorial.

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