Sandhya.np14 at 01:52, 9 March 2015

2015-03-09T01:52:00Z

Sandhya.np14 at 01:50, 9 March 2015

2015-03-09T01:50:31Z

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Pratik kamble at 11:24, 9 July 2014

2014-07-09T11:24:19Z

Pratik kamble at 11:23, 9 July 2014

2014-07-09T11:23:40Z

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Vasudeva ahitanal at 06:46, 8 April 2014

2014-04-08T06:46:02Z

Minal: Created page with '{| border=1 !Time !Narration |- | 0:00 |Welcome to this spoken tutorial on Linux File System. |- | 0:04 |I am using Ubuntu 10.04. |- | 0:07 |We assume that you know how to get s…'

2012-12-28T09:32:30Z

Created page with '{| border=1 !Time !Narration |- | 0:00 |Welcome to this spoken tutorial on Linux File System. |- | 0:04 |I am using Ubuntu 10.04. |- | 0:07 |We assume that you know how to get s…'

New page

{| border=1
!Time
!Narration
|-
| 0:00
|Welcome to this spoken tutorial on Linux File System.
|-
| 0:04
|I am using Ubuntu 10.04.
|-
| 0:07
|We assume that you know how to get started with the Linux operating system and have some basic idea about commands.
|-
| 0:13
|If you are interested, it is available through another spoken tutorial, on the following website http://spoken-tutorial.org
|-
| 0:25
|Also note that linux is case sensitive.
|-
| 0:28
| All the commands used in this tutorial are in lower case unless otherwise mentioned.
|-
| 0:36
|In Linux almost everything is a file.
|-
| 0:39
|So what is a file? In real life we know that a file is where we store our documents and papers.
|-
| 0:47
|Similarly in Linux a file is a container for storing information.
|-
| 0:53
|Next what is a directory?
|-
| 0:56
|A directory can be understood as a collection of files and other (sub)directories.
|-
| 1:02
|A directory helps us in organising our files in a systematic manner.
|-
| 1:08
|This is like what we call folders in Windows.
|-
| 1:12
| It allows different users to have their own directories with their files which others cannot access or modify.
|-
| 1:20
|Also if there are no directories, all the files on the system need to have unique names,which would be very difficult to maintain.
|-
| 1:31
|Though these definitions of files and directories are good to get a general feel about them, they are not entirely accurate.
|-
| 1:42
|As well as its contents, a file has a name and some properties, or “administrative information”; that is, the file’s creation/modification date and its permissions.
|-
| 1:55
|The properties are stored in the file’s inode, a special block of data in the file system that also contains the length of the file and where on the disk it’s stored.
|-
| 2:08
|The system uses the number of the file’s inode; the directory structure just names the file for our benefit as its easier for us to remember names than large numbers.
|-
|2:23
|Contrary to its oversimplified definition, a directory doesnot actually store other files ,it is itself a file that holds the inode numbers and names of other files.
|-
| 2:37
|In fact in Linux there are three kinds of files:
|-
| 2:41
|1 Regular Files or Ordinary files: It contains only data , as a stream of characters.
|-
| 2:48
|2 Directories: As we just saw in the previous slides.
|-
| 2:52
|3 Device Files: All hardware devices and peripherals are represented as files in Linux.
|-
| 2:59
|A CD, a Harddisk or even an usb stick, everything is a file in Linux. But why is this so? This helps to read and write these devices in a way similar to that for ordinary files.
|-
| 3:15
|All files in Linux are related, in short all form a family much like we do.
|-
| 3:22
|A directory containing say some files and subdirectories will have a parent – child relationship with each other. This gives rise to the Linux File System Tree.
|-
| 3:34
|At the top is the root( denoted by a frontslash /). It contains all the other files and directories.
|-
| 3:42
|This also helps in easy navigation from one file or directory to other, if we know the correct path.
|-
| 3:51
|As we work with a Linux file system, it seems that we are moving along this tree.
|-
| 3:56
|One command and there you are teleported from one place to other.
|-
| 4:01
|Sounds interesting!! Indeed it is. As we will see.
|-
| 4:05
|When we login into the Linux system we are by default in a home directory.
|-
| 4:11
|Now Switch to the terminal.
|-
| 4:13
| Ctrl+alt+T helps to start a terminal in Ubuntu.
|-
| 4:17
|This command may not work in all unix systems, however. A general procedure to open a terminal is already explained in another spoken tutorial.
|-
| 4:27
|To see the home directory , Type at the command prompt
"echo space dollar H-O-M-E in capital" and press enter.
|-
| 4:40
|This gives the pathname of our home directory.
|-
| 4:44
|We can move around from one directory to other.
|-
| 4:47
|But any time we can be in one directory and this directory is known as the current directory or working directory. Now go back to slides.
|-
| 4:56
|The pwd command helps us to see the current directory. pwd stands for present working directory.
|-
| 5:03
|Type at the command prompt "pwd" and press enter. Now this is our present working directory.
|-
| 5:13
|We have said that we can move from one directory to other.
|-
| 5:17
|But how do we do so? We have the cd command for this purpose.
|-
| 5:22
|You have to type the command cd followed by the pathname of the directory you want to move to.
|-
| 5:28
|Lets again see our current directory by typing pwd at the command prompt and press enter.
|-
|5:37
| So, now we are placed in this directory.
|-
| 5:41
|Now say we want to move to slash usr directory. So, type
"cd space slash usr" . Remember here slash in linux means front slash and press enter.
|-
| 5:56
|Now lets see our current directory. Type pwd and press enter.
|-
| 6:03
|Yes we have moved to slash usr directory.
|-
| 6:08
|The problem here is the pathnames can be very long, this is because these are Absolute Pathnames that enlist the entire path staring from the root directory.
|-
| 6:18
|Instead we may use Relative pathnames that begin from the current directory.
|-
| 6:23
|Here we need to know two special characters.
'''dot''' that represent the current directory and '''dot dot''' that represent the parent directory of the current directory.
|-
| 6:36
|Now let us have a brief session on cd command
|-
| 6:40
|The command cd without any argument is used to move back to the home directory.
|-
| 6:46
|Type at the command prompt "cd" and press enter.
|-
| 6:51
|Now check our current directory by the pwd command.
|-
| 6:55
|So, now we are back in our home directory
<nowiki>/home/gnuhata [ narration- slash home slash gnuhata ] </nowiki>
|-
| 7:01
|Now let us move to music directory. Type at the command prompt "cd space Music(M in capital) slash" and press enter
|-
| 7:13
|Now check our current directory by the pwd command. pwd and press enter. See, we have moved /home/gnuhata/Music
|-
| 7:26
|Let us go to the parent directory from Music. For that you have to use cd command with dot dot.
|-
| 7:33
|Type at the command prompt cd space dot dot and press enter.
|-
| 7:40
|Now check our present directory by typing pwd. We are again in /home/gnuhata
|-
| 7:51
|Now lets try to move to a subdirectory of the current directory using dot.
|-
| 7:58
|Type at the command prompt cd space dot slash Documents(D in capital) slash. Press enter.
|-
| 8:09
|Check our current directory by typing pwd. We are at /home/gnuhata/Documents
|-
| 8:19
|Let me clear the screen by pressing control L. So you can see clearly.
|-
| 8:23
|To go back to our home directory by cd command.
Type cd and press enter.
|-
| 8:32
|Again check our current directory by pwd command. We are back to /home/gnuhata .
|-
| 8:41
|<nowiki>We can combine any number of .. [narration - dot dot] separated by / [narration- slash] in a relative path . </nowiki>
|-
| 8:47
|In this slide, we can see the file system hierarchy. Root or / is at the top. home and bin are two sub-directories under root. username , here the directory named gnuhata is a sub-directory under home.
|-
| 9:05
| So, now we are in /home/gnuhata. Now how can we go to the bin directory?
|-
| 9:12
|Type at the command prompt
"cd space dot dot slash dot dot slash bin" and press enter.
|-
| 9:23
|Check our current directory by the command pwd.
<nowiki>We are at /bin [narration - slash bin] </nowiki>
|-
| 9:30
|<nowiki>The first .. [narration-dot dot] takes us from /home/gnuhata [narration - slash home slash gnuhata] to /home [narration - slash home] .
|-
| 9:37
|The next takes us from /home to </nowiki>root.
|-
| 9:43
|Now from / or root, we have moved to /bin directory.
|-
| 9:48
|Go back to our home directory by the command cd.
|-
| 9:52
|To create a directory we use the mkdir command.

|-
| 9:56
|You have to type the command and name of directory to be created and a directory would be created under the current directory.
|-
| 10:04
|To create a directory named testdir, type the command "mkdir space testdir" and press enter.
|-
| 10:15
|This creates the testdir directory successfully.
|-
| 10:19
|Note that, there is no explicit notification of successful directory creation or removal.
|-
| 10:25
| If you do not get any error message, it denotes successful execution.
|-
| 10:30
|We can also use the relative or absolute pathname to create a directory anywhere in the tree provided we have the permission to do so and a directory by that name does not already exist.
|-
| 10:43
|This process can be used for making multiple directories or even a hierarchy of directories.
|-
| 10:49
|Type "mkdir space test1 space test2 and press enter ,this will make two directories named test1 and test2 under the present directory.
|-
| 11:06
|Type "mkdir space testtree space testtree slash test3".
|-
| 11:20
|This will make a directory testtree and another directory test3 which is a sub-directory under testtree.
|-
| 11:28
|So, we have created four directories namely testdir,test1,test2 and testtree in the current directory, out of which first three are empty and the last one contains a subdirectory namely test3.
|-
| 11:47
|Similar to mkdir is the rmdir command which is used for removing a directory or directories.
|-
| 11:56
|The command "rmdir space test1" removes the test1 directory successfully.
|-
| 12:09
|A directory can be removed only if you are its owner, your current directory is hierarchically above the directory to be removed and the directory is empty.
|-
| 12:23
|Now type at the command prompt
"cd space testtree slash test3"
|-
| 12:35
|So, we are now in test3 directory which is a subdirectory under testtree.
|-
| 12:42
|Lets try to remove the testdir directory by typing the command "rmdir space testdir". Press enter.
|-
| 12:55
|We see it can't be done, because the current directory is not hierarchically above the directory to be removed.
|-
| 13:02
|So,we have to go to the directory which is hierarchically above testdir directory.
|-
| 13:08
|Type "cd space dot dot" and press enter.
|-
| 13:14
|Now, go back to our parent directory by typing the command "cd space dot dot".
|-
| 13:20
|Now, again try the previous command.
|-
| 13:24
|Type "rmdir space testdir". Press enter.
|-
| 13:30
|The testdir directory is successfully deleted. Note that, testdir directory was also empty.
|-
| 13:38
|Multiple directories or a hierarchy of directories can be removed at once.So, try to delete the testtree directory along with its subdirectory test3.
|-
| 13:48
|Type at the command prompt
"rmdir space testtree space testtree slash test3 "press enter.
|-
| 14:02
|See, it is giving the error message that 'testree' directory cannot be removed because testtree is not empty.
|-
| 14:11
|But one thing which you may miss is that testtree/test3 has been deleted as it was empty.
|-
| 14:19
|To check that, type at the command prompt "cd space testtree" and press enter.
|-
| 14:27
|Now type "ls" and press enter. See, the directory contains nothing. So, test3 was deleted.
|-
| 14:36
|So in this linux tutorial we have learnt about Linux Files and directories and how to work with Linux Directories. See them, move between them, make them,remove them.
|-
| 14:49
|This brings me to the end of this tutorial. Spoken Tutorials are a part of the Talk to a Teacher project, supported by the National Mission on Education through ICT.
|-
| 15:03
|More information this is available at the following link
|-
| 15:08
|This script has been contributed by ----------------------(name of the translator) and this is -----------------------(name of the recorder) from --------------------------(name of the place)signing off . Thanks for joining.

|}

@@ Line 16: / Line 16: @@
 |-
 | 00:25
-|Also note that Linux is case sensitive.
+|Also note that Linux is ''case sensitive''.
 |-
 | 00:28

@@ Line 221: / Line 221: @@
 |In this slide, we can see the file system hierarchy. Root or / is at the top. home and bin are two sub-directories under root. username , here the directory named gnuhata is a sub-directory under home.
 |-
-| 9:05
+| 09:05
 | So, now we are in /home/gnuhata. Now how can we go to the bin directory?
 |-
-| 9:12
+| 09:12
 |Type at the command prompt
 "cd space dot dot slash dot dot slash bin" and press enter.
 |-
-| 9:23
+| 09:23
 |Check our current directory by the command pwd.
 <nowiki>We are at /bin [narration - slash bin] </nowiki>
 |-
-| 9:30
+| 09:30
 |<nowiki>The first .. [narration-dot dot] takes us from /home/gnuhata [narration - slash home slash gnuhata] to /home [narration - slash home].</nowiki>
 |-
-| 9:37
+| 09:37
 |<nowiki>The next takes us from /home to </nowiki>root.
 |-
-| 9:43
+| 09:43
 |Now from / or root, we have moved to /bin directory.
 |-
-| 9:48
+| 09:48
 |Go back to our home directory by the command cd.
 |-
-| 9:52
+| 09:52
 |To create a directory we use the mkdir command.
 |-
-| 9:56
+| 09:56
 |You have to type the command and name of directory to be created and a directory would be created under the current directory.
 |-