Difference between revisions of "BOSS-Linux/C2/File-System/English-timed"
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| 00:00 | | 00:00 | ||
− | |Welcome to this spoken tutorial on Linux File System. | + | |Welcome to this spoken tutorial on '''Linux File System'''. |
|- | |- | ||
| 00:04 | | 00:04 | ||
− | |I am using Linux Operating system. | + | |I am using '''Linux Operating system'''. |
|- | |- | ||
| 00:08 | | 00:08 | ||
− | |We assume that you know how to get started with the Linux operating system and have some basic idea about commands. | + | |We assume that you know how to get started with the Linux operating system and have some basic idea about '''commands'''. |
|- | |- | ||
| 00:16 | | 00:16 | ||
− | |If you are interested, it is available through another spoken tutorial | + | |If you are interested, it is available through another spoken tutorial on the following website http://spoken-tutorial.org |
|- | |- | ||
| 00:28 | | 00:28 | ||
− | |Also note that linux is case sensitive. | + | |Also note that linux is '''case sensitive'''. |
|- | |- | ||
| 00:32 | | 00:32 | ||
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| 00:41 | | 00:41 | ||
− | |In Linux almost everything is a file. | + | |In Linux, almost everything is a file. |
|- | |- | ||
| 00:44 | | 00:44 | ||
− | |So what is a file? In real life we know that a file is where we store our documents and papers. | + | |So, what is a file? In real life, we know that a file is where we store our documents and papers. |
|- | |- | ||
| 00:54 | | 00:54 | ||
− | |Similarly in Linux a file is a container for storing information. | + | |Similarly, in Linux a file is a container for storing information. |
|- | |- | ||
| 01:00 | | 01:00 | ||
− | |Next what is a directory? | + | |Next, what is a directory? |
|- | |- | ||
| 01:03 | | 01:03 | ||
Line 37: | Line 37: | ||
|- | |- | ||
| 01:10 | | 01:10 | ||
− | |A directory helps us in | + | |A directory helps us in organizing our files in a systematic manner. |
|- | |- | ||
| 01:16 | | 01:16 | ||
Line 46: | Line 46: | ||
|- | |- | ||
| 01:30 | | 01:30 | ||
− | |Also if there are no directories, all the files on the system need to have unique names | + | |Also, if there are no directories, all the files on the system need to have unique names which would be very difficult to maintain. |
|- | |- | ||
| 01:41 | | 01:41 | ||
− | |These definitions of files and directories are good to get a general feel about them | + | |These definitions of files and directories are good to get a general feel about them; they are not entirely accurate. |
|- | |- | ||
| 01:51 | | 01:51 | ||
− | |As well as its contents, a file has a name and some properties | + | |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'''. |
|- | |- | ||
| 02:05 | | 02:05 | ||
− | |Thus properties are stored in the file’s inode | + | |Thus, 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. |
|- | |- | ||
| 02:20 | | 02:20 | ||
− | |The system uses the number of the file’s '''inode''' ; the directory structure just names the file for our benefit as | + | |The system uses the number of the file’s '''inode''' ; the directory structure just names the file for our benefit as it's easier for us to remember names than larger numbers. |
|- | |- | ||
|02:35 | |02:35 | ||
− | |Contrary to its oversimplified definition, a directory | + | |Contrary to its oversimplified definition, a directory does not actually store other files, it itself is a file that holds the inode numbers and names of other files. |
|- | |- | ||
| 02:49 | | 02:49 | ||
− | |In fact in Linux there are three kinds of files: | + | |In fact, in Linux there are three kinds of files: |
|- | |- | ||
| 02:54 | | 02:54 | ||
− | |Regular Files or Ordinary files: It contains only data , as a stream of characters. | + | |Regular Files or Ordinary files: It contains only data, as a stream of characters. |
|- | |- | ||
| 03:01 | | 03:01 | ||
Line 76: | Line 76: | ||
|- | |- | ||
| 03:14 | | 03:14 | ||
− | |A CD, a | + | |A CD, a Hard disk 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. |
|- | |- | ||
| 03:32 | | 03:32 | ||
− | |All files in Linux are related | + | |All files in Linux are related. In short, all form a family much like we do. |
|- | |- | ||
| 03:39 | | 03:39 | ||
− | |A directory containing say some files and | + | |A directory containing say- some files and sub-directories, will have a parent – child relationship with each other. This gives rise to the '''Linux File System Tree'''. |
|- | |- | ||
| 03:52 | | 03:52 | ||
− | |At the top is the root( denoted by a frontslash /). It contains all the other files and directories. | + | |At the top is the '''root'''( denoted by a frontslash /). It contains all the other files and directories. |
|- | |- | ||
| 04:04 | | 04:04 | ||
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|- | |- | ||
| 04:18 | | 04:18 | ||
− | |One command and there you are teleported from one place to other. | + | |One command and there you are... teleported from one place to other. |
|- | |- | ||
| 04:24 | | 04:24 | ||
− | |Sounds interesting!! Indeed it is | + | |Sounds interesting!! Indeed it is, as we will see. |
|- | |- | ||
| 04:29 | | 04:29 | ||
− | |When we login into the Linux system we are by default in a home directory. | + | |When we login into the Linux system, we are by default in a '''home directory'''. |
|- | |- | ||
| 04:36 | | 04:36 | ||
− | |Now | + | |Now, switch to the '''terminal'''. |
|- | |- | ||
| 04:39 | | 04:39 | ||
− | |To see the home directory , | + | |To see the home directory , type at the command prompt: '''echo space dollar H-O-M-E''' in capital and press '''Enter'''. |
|- | |- | ||
| 04:53 | | 04:53 | ||
− | |This gives the | + | |This gives the path name of our '''home''' directory. |
|- | |- | ||
| 04:57 | | 04:57 | ||
Line 116: | Line 116: | ||
|- | |- | ||
| 05:01 | | 05:01 | ||
− | |But any time we can be in one directory and this directory is known as the current directory or working directory. | + | |But, any time we can be in one directory and this directory is known as the '''current directory''' or '''working directory'''. |
|- | |- | ||
| 05:09 | | 05:09 | ||
− | |The '''pwd''' command helps us to see the current directory. '''pwd''' stands for present working directory. | + | |The '''pwd''' command helps us to see the current directory. '''pwd''' stands for '''present working directory'''. |
|- | |- | ||
| 05:18 | | 05:18 | ||
− | |Type at the command prompt ' | + | |Type at the command prompt '''pwd''' and press '''Enter'''. Now, this is our present working directory. |
|- | |- | ||
| 05:28 | | 05:28 | ||
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|- | |- | ||
| 05:39 | | 05:39 | ||
− | |You have to type the command '''cd''' followed by the | + | |You have to type the command '''cd''' followed by the path name of the directory you want to move to. |
|- | |- | ||
| 05:47 | | 05:47 | ||
− | | | + | |Let's again see our current directory by typing '''pwd''' at the '''command prompt''' and press '''Enter'''. |
|- | |- | ||
|05:57 | |05:57 | ||
Line 140: | Line 140: | ||
|- | |- | ||
| 06:01 | | 06:01 | ||
− | |Now say we want to move to '''slash usr''' directory. So, type | + | |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'''. |
|- | |- | ||
| 06:17 | | 06:17 | ||
− | |Now lets see our current directory. Type '''pwd''' and press | + | |Now lets see our current directory. Type '''pwd''' and press '''Enter'''. |
|- | |- | ||
| 06:24 | | 06:24 | ||
− | |Yes we have moved to '''slash usr''' directory. | + | |Yes, we have moved to '''slash usr''' directory. |
|- | |- | ||
| 06:30 | | 06:30 | ||
− | |The problem here is the | + | |The problem here is, the path names can be very long; this is because these are '''Absolute Path names''' that enlist the entire path, starting from the '''root directory'''. |
|- | |- | ||
| 06:42 | | 06:42 | ||
− | |Instead we may use Relative | + | |Instead, we may use '''Relative path names''' that begin from the current directory. |
|- | |- | ||
| 06:48 | | 06:48 | ||
− | |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. | + | |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. |
|- | |- | ||
| 07:02 | | 07:02 | ||
− | |Now let us have a brief session on '''cd''' command | + | |Now, let us have a brief session on '''cd''' command. |
|- | |- | ||
| 07:06 | | 07:06 | ||
− | |The command '''cd''' without any argument is used to move back | + | |The command '''cd''', without any argument, is used to move back to the '''home directory'''. |
|- | |- | ||
| 07:13 | | 07:13 | ||
− | |Type at the command prompt | + | |Type at the command prompt '''cd''' and press '''Enter'''. |
|- | |- | ||
| 07:19 | | 07:19 | ||
Line 170: | Line 170: | ||
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| 07:23 | | 07:23 | ||
− | |So, now we are back in our home directory '''/home/gnuhata''' [ slash home slash gnuhata ] | + | |So, now we are back in our home directory- '''/home/gnuhata''' [slash home slash gnuhata]. |
|- | |- | ||
| 07:30 | | 07:30 | ||
− | |Now let us move to music directory. Type at the command prompt | + | |Now, let us move to music directory. Type at the command prompt '''cd space Music''' (M in capital) slash and press '''Enter'''. |
|- | |- | ||
| 07:43 | | 07:43 | ||
− | |Now check our current directory by the '''pwd''' command. '''pwd''' and press enter. See, we have moved ''' /home/gnuhata/Music ''' | + | |Now check our current directory by the '''pwd''' command. '''pwd''' and press enter. See, we have moved ''' /home/gnuhata/Music'''. |
|- | |- | ||
| 07:57 | | 07:57 | ||
− | |Let us go to the parent directory of Music. For that you have to use cd command with dot dot. | + | |Let us go to the '''parent directory''' of Music. For that, you have to use '''cd''' command with dot dot. |
|- | |- | ||
| 08:04 | | 08:04 | ||
− | |Type at the command prompt '''cd space dot dot''' and press | + | |Type at the command prompt: '''cd space dot dot''' and press '''Enter'''. |
|- | |- | ||
| 08:11 | | 08:11 | ||
− | |Now check our present directory by typing '''pwd.''' We are again in '''/home/gnuhata''' | + | |Now check our present directory by typing '''pwd.''' We are again in '''/home/gnuhata'''. |
|- | |- | ||
| 08:23 | | 08:23 | ||
− | |Now | + | |Now, let's try to move to a sub-directory of the current directory using dot. |
|- | |- | ||
| 08:30 | | 08:30 | ||
− | |Type at the command prompt '''cd space dot slash Documents(D in capital) slash''' | + | |Type at the command prompt: '''cd space dot slash Documents''' (D in capital) slash. Press '''Enter'''. |
|- | |- | ||
| 08:42 | | 08:42 | ||
− | |Check our current directory by typing '''pwd.''' We are at ''' /home/gnuhata/Documents''' | + | |Check our current directory by typing '''pwd.''' We are at- ''' /home/gnuhata/Documents'''. |
|- | |- | ||
| 08:53 | | 08:53 | ||
− | |Let me clear the screen by pressing control L. So you can see clearly. | + | |Let me clear the screen by pressing '''control L'''. So you can see clearly. |
|- | |- | ||
| 08:58 | | 08:58 | ||
− | |To go back to our home directory by '''cd''' command | + | |To go back to our home directory by '''cd''' command, type '''cd''' and press '''Enter'''. |
|- | |- | ||
| 09:07 | | 09:07 | ||
− | |Again check our current directory by '''pwd''' command. We are back to '''/home/gnuhata''' . | + | |Again check our current directory by '''pwd''' command. We are back to '''/home/gnuhata'''. |
|- | |- | ||
| 09:17 | | 09:17 | ||
− | |We can combine any number of | + | |We can combine any number of dot dot separated by slash in a '''relative path'''. |
|- | |- | ||
| 09:23 | | 09:23 | ||
− | |In this slide, we can see the file system hierarchy. '''Root''' or '''slash''' 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.''' | + | |In this slide, we can see the file system hierarchy. '''Root''' or '''slash''' 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.''' |
|- | |- | ||
| 09:43 | | 09:43 | ||
− | | So, now we are in '''/home/gnuhata.''' Now how can we go to the bin directory? | + | | So, now we are in '''/home/gnuhata.''' Now, how can we go to the '''bin''' directory? |
|- | |- | ||
| 09:51 | | 09:51 | ||
− | |Type at the command prompt | + | |Type at the command prompt: '''cd space dot dot slash dot dot slash bin''' and press '''Enter'''. |
|- | |- | ||
| 10:03 | | 10:03 | ||
− | |Check our current directory by the command '''pwd.''' We are at /bin (slash bin) | + | |Check our current directory by the command '''pwd.''' We are at '''/bin''' (slash bin). |
|- | |- | ||
| 10:11 | | 10:11 | ||
− | |The first .. (dot dot) takes us from /home/gnuhata (slash home slash gnuhata) to /home (slash home) | + | |The first ".." (dot dot) takes us from /home/gnuhata (slash home slash gnuhata) to /home (slash home). |
|- | |- | ||
| 10:18 | | 10:18 | ||
− | |The next takes us from '''slash home''' to root. | + | |The next, takes us from '''slash home''' to '''root'''. |
|- | |- | ||
| 10:24 | | 10:24 | ||
− | |Now from root or slash, we have moved to /bin directory. | + | |Now from '''root''' or slash, we have moved to '''/bin''' directory. |
|- | |- | ||
| 10:30 | | 10:30 | ||
Line 237: | Line 237: | ||
|- | |- | ||
| 10:34 | | 10:34 | ||
− | |To create a directory we use the '''mkdir''' command. | + | |To create a directory, we use the '''mkdir''' command. |
|- | |- | ||
| 10:40 | | 10:40 | ||
− | |You have to type the command and name of directory to be created and a directory would be created under the current directory. | + | |You have to type the command and the name of directory to be created and a directory would be created under the current directory. |
|- | |- | ||
| 10:49 | | 10:49 | ||
− | |To create a directory named '''testdir''', type the command ' | + | |To create a directory named '''testdir''', type the command: '''mkdir space testdir''' and press '''Enter'''. |
|- | |- | ||
| 11:01 | | 11:01 | ||
Line 256: | Line 256: | ||
|- | |- | ||
| 11:18 | | 11:18 | ||
− | |We can also use the relative or absolute | + | |We can also use the '''relative''' or '''absolute path name''' 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. |
|- | |- | ||
| 11:33 | | 11:33 | ||
Line 262: | Line 262: | ||
|- | |- | ||
| 11:39 | | 11:39 | ||
− | |Type | + | |Type: '''mkdir space test1 space test2''' and press '''Enter'''. This will make two directories named '''test1''' and '''test2''' under the present directory. |
|- | |- | ||
| 11:57 | | 11:57 | ||
− | |Type "'mkdir space testtree space testtree slash test3'". | + | |Type: "'mkdir space testtree space testtree slash test3'". |
|- | |- | ||
| 12:11 | | 12:11 | ||
Line 271: | Line 271: | ||
|- | |- | ||
| 12:20 | | 12:20 | ||
− | |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 | + | |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 sub-directory namely test3. |
|- | |- | ||
| 12:40 | | 12:40 | ||
− | |Similar to the '''mkdir''' is the '''rmdir''' command which is used for removing a directory or directories. | + | |Similar to the '''mkdir''' command is the '''rmdir''' command which is used for removing a directory or directories. |
|- | |- | ||
| 12:50 | | 12:50 | ||
− | |The command | + | |The command '''rmdir space test1''' removes the '''test1''' directory successfully. |
|- | |- | ||
| 13:00 | | 13:00 | ||
Line 283: | Line 283: | ||
|- | |- | ||
| 13:13 | | 13:13 | ||
− | |Now type at the command prompt '"cd space testtree slash test3"' | + | |Now type at the command prompt: '"cd space testtree slash test3"'. |
|- | |- | ||
| 13:25 | | 13:25 | ||
− | |So, we are now in '''test3''' directory which is a | + | |So, we are now in '''test3''' directory which is a sub-directory under '''testtree.''' |
|- | |- | ||
| 13:33 | | 13:33 | ||
− | | | + | |Let's try to remove the '''testdir''' directory by typing the command '''rmdir space testdir'''. Press '''Enter'''. |
|- | |- | ||
| 13:46 | | 13:46 | ||
− | |We see it can't be done | + | |We see it can't be done because the current directory is not hierarchically above the directory to be removed. |
|- | |- | ||
| 13:54 | | 13:54 | ||
− | |So,we have to go to the directory which is hierarchically above '''testdir''' directory. | + | |So, we have to go to the directory which is hierarchically above '''testdir''' directory. |
|- | |- | ||
| 14:00 | | 14:00 | ||
− | |Type "'cd space dot dot"' and press | + | |Type: "'cd space dot dot"' and press '''Enter'''. |
|- | |- | ||
| 14:06 | | 14:06 | ||
− | |Now, go back to our parent directory by typing the command "'cd space dot dot'". | + | |Now, go back to our '''parent directory''' by typing the command "'cd space dot dot'". |
|- | |- | ||
| 14:13 | | 14:13 | ||
Line 307: | Line 307: | ||
|- | |- | ||
| 14:16 | | 14:16 | ||
− | |Type "rmdir space testdir". Press | + | |Type: "rmdir space testdir". Press '''Enter'''. |
|- | |- | ||
| 14:23 | | 14:23 | ||
Line 313: | Line 313: | ||
|- | |- | ||
| 14:32 | | 14:32 | ||
− | |Multiple directories or a hierarchy of directories can be removed at once.So, try to delete the '''testtree''' directory along with its | + | |Multiple directories or a hierarchy of directories can be removed at once. So, try to delete the '''testtree''' directory along with its sub-directory '''test3.''' |
|- | |- | ||
| 14:43 | | 14:43 | ||
− | |Type at the command prompt ' | + | |Type at the command prompt: '''rmdir space testtree space testtree slash test3''' press '''Enter'''. |
|- | |- | ||
| 14:57 | | 14:57 | ||
− | |See, it is giving the error message that | + | |See, it is giving the error message that 'testree' directory cannot be removed because 'testtree' is not empty. |
|- | |- | ||
| 15:07 | | 15:07 | ||
Line 325: | Line 325: | ||
|- | |- | ||
| 15:16 | | 15:16 | ||
− | |To check that, type at the command prompt | + | |To check that, type at the command prompt: '''cd space testtree''' and press '''Enter'''. |
|- | |- | ||
| 15:25 | | 15:25 | ||
− | |Now type | + | |Now, type '''ls''' and press '''Enter'''. See, the directory contains nothing. So, 'test3' was deleted. |
|- | |- | ||
| 15:34 | | 15:34 | ||
− | |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. | + | |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. |
|- | |- | ||
| 15:48 | | 15:48 | ||
− | |This brings me to the end of this tutorial. Spoken Tutorials are | + | |This brings me to the end of this tutorial. Spoken Tutorials are part of the "Talk to a Teacher" project, supported by the National Mission on Education through ICT. |
|- | |- | ||
| 16:02 | | 16:02 | ||
− | |More information this is available at the following link | + | |More information on this is available at the following link. |
|- | |- | ||
| 16:08 | | 16:08 | ||
− | |This is Anusha Kadambala signing off. Thanks for joining. | + | |This is Anusha Kadambala, signing off. Thanks for joining. |
|} | |} |
Latest revision as of 21:48, 10 August 2015
Time | Narration |
00:00 | Welcome to this spoken tutorial on Linux File System. |
00:04 | I am using Linux Operating system. |
00:08 | We assume that you know how to get started with the Linux operating system and have some basic idea about commands. |
00:16 | If you are interested, it is available through another spoken tutorial on the following website http://spoken-tutorial.org |
00:28 | Also note that linux is case sensitive. |
00:32 | All the commands used in this tutorial are in lower case unless otherwise mentioned. |
00:41 | In Linux, almost everything is a file. |
00:44 | So, what is a file? In real life, we know that a file is where we store our documents and papers. |
00:54 | Similarly, in Linux a file is a container for storing information. |
01:00 | Next, what is a directory? |
01:03 | A directory can be understood as a collection of files and other (sub)directories. |
01:10 | A directory helps us in organizing our files in a systematic manner. |
01:16 | This is like what we call folders in Windows. |
01:20 | It allows different users to have their own directories with their files which others cannot access or modify. |
01:30 | Also, if there are no directories, all the files on the system need to have unique names which would be very difficult to maintain. |
01:41 | These definitions of files and directories are good to get a general feel about them; they are not entirely accurate. |
01:51 | 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. |
02:05 | Thus, 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. |
02:20 | The system uses the number of the file’s inode ; the directory structure just names the file for our benefit as it's easier for us to remember names than larger numbers. |
02:35 | Contrary to its oversimplified definition, a directory does not actually store other files, it itself is a file that holds the inode numbers and names of other files. |
02:49 | In fact, in Linux there are three kinds of files: |
02:54 | Regular Files or Ordinary files: It contains only data, as a stream of characters. |
03:01 | Directories: As we just saw in the previous slides. |
03:07 | Device Files: All hardware devices and peripherals are represented as files in Linux. |
03:14 | A CD, a Hard disk 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. |
03:32 | All files in Linux are related. In short, all form a family much like we do. |
03:39 | A directory containing say- some files and sub-directories, will have a parent – child relationship with each other. This gives rise to the Linux File System Tree. |
03:52 | At the top is the root( denoted by a frontslash /). It contains all the other files and directories. |
04:04 | This also helps in easy navigation from one file or directory to other, if we know the correct path. |
04:12 | As we work with a Linux file system, it seems that we are moving along this tree. |
04:18 | One command and there you are... teleported from one place to other. |
04:24 | Sounds interesting!! Indeed it is, as we will see. |
04:29 | When we login into the Linux system, we are by default in a home directory. |
04:36 | Now, switch to the terminal. |
04:39 | To see the home directory , type at the command prompt: echo space dollar H-O-M-E in capital and press Enter. |
04:53 | This gives the path name of our home directory. |
04:57 | We can move around from one directory to other. |
05:01 | But, any time we can be in one directory and this directory is known as the current directory or working directory. |
05:09 | The pwd command helps us to see the current directory. pwd stands for present working directory. |
05:18 | Type at the command prompt pwd and press Enter. Now, this is our present working directory. |
05:28 | We have said that we can move from one directory to other. |
05:32 | But how do we do so? We have the cd command for this purpose. |
05:39 | You have to type the command cd followed by the path name of the directory you want to move to. |
05:47 | Let's again see our current directory by typing pwd at the command prompt and press Enter. |
05:57 | So, now we are placed in this directory. |
06:01 | 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. |
06:17 | Now lets see our current directory. Type pwd and press Enter. |
06:24 | Yes, we have moved to slash usr directory. |
06:30 | The problem here is, the path names can be very long; this is because these are Absolute Path names that enlist the entire path, starting from the root directory. |
06:42 | Instead, we may use Relative path names that begin from the current directory. |
06:48 | 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. |
07:02 | Now, let us have a brief session on cd command. |
07:06 | The command cd, without any argument, is used to move back to the home directory. |
07:13 | Type at the command prompt cd and press Enter. |
07:19 | Now check our current directory by the pwd command. |
07:23 | So, now we are back in our home directory- /home/gnuhata [slash home slash gnuhata]. |
07:30 | Now, let us move to music directory. Type at the command prompt cd space Music (M in capital) slash and press Enter. |
07:43 | Now check our current directory by the pwd command. pwd and press enter. See, we have moved /home/gnuhata/Music. |
07:57 | Let us go to the parent directory of Music. For that, you have to use cd command with dot dot. |
08:04 | Type at the command prompt: cd space dot dot and press Enter. |
08:11 | Now check our present directory by typing pwd. We are again in /home/gnuhata. |
08:23 | Now, let's try to move to a sub-directory of the current directory using dot. |
08:30 | Type at the command prompt: cd space dot slash Documents (D in capital) slash. Press Enter. |
08:42 | Check our current directory by typing pwd. We are at- /home/gnuhata/Documents. |
08:53 | Let me clear the screen by pressing control L. So you can see clearly. |
08:58 | To go back to our home directory by cd command, type cd and press Enter. |
09:07 | Again check our current directory by pwd command. We are back to /home/gnuhata. |
09:17 | We can combine any number of dot dot separated by slash in a relative path. |
09:23 | In this slide, we can see the file system hierarchy. Root or slash 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. |
09:43 | So, now we are in /home/gnuhata. Now, how can we go to the bin directory? |
09:51 | Type at the command prompt: cd space dot dot slash dot dot slash bin and press Enter. |
10:03 | Check our current directory by the command pwd. We are at /bin (slash bin). |
10:11 | The first ".." (dot dot) takes us from /home/gnuhata (slash home slash gnuhata) to /home (slash home). |
10:18 | The next, takes us from slash home to root. |
10:24 | Now from root or slash, we have moved to /bin directory. |
10:30 | Go back to our home directory by the command cd. |
10:34 | To create a directory, we use the mkdir command. |
10:40 | You have to type the command and the name of directory to be created and a directory would be created under the current directory. |
10:49 | To create a directory named testdir, type the command: mkdir space testdir and press Enter. |
11:01 | This creates the testdir directory successfully. |
11:05 | Note that, there is no explicit notification of successful directory creation or removal. |
11:13 | If you do not get any error message, it denotes successful execution. |
11:18 | We can also use the relative or absolute path name 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. |
11:33 | This process can be used for making multiple directories or even a hierarchy of directories. |
11:39 | Type: mkdir space test1 space test2 and press Enter. This will make two directories named test1 and test2 under the present directory. |
11:57 | Type: "'mkdir space testtree space testtree slash test3'". |
12:11 | This will make a directory testtree and another directory test3 which is a sub-directory under testtree. |
12:20 | 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 sub-directory namely test3. |
12:40 | Similar to the mkdir command is the rmdir command which is used for removing a directory or directories. |
12:50 | The command rmdir space test1 removes the test1 directory successfully. |
13:00 | 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. |
13:13 | Now type at the command prompt: '"cd space testtree slash test3"'. |
13:25 | So, we are now in test3 directory which is a sub-directory under testtree. |
13:33 | Let's try to remove the testdir directory by typing the command rmdir space testdir. Press Enter. |
13:46 | We see it can't be done because the current directory is not hierarchically above the directory to be removed. |
13:54 | So, we have to go to the directory which is hierarchically above testdir directory. |
14:00 | Type: "'cd space dot dot"' and press Enter. |
14:06 | Now, go back to our parent directory by typing the command "'cd space dot dot'". |
14:13 | Now, again try the previous command. |
14:16 | Type: "rmdir space testdir". Press Enter. |
14:23 | The testdir directory is successfully deleted. Note that, testdir directory was also empty. |
14:32 | Multiple directories or a hierarchy of directories can be removed at once. So, try to delete the testtree directory along with its sub-directory test3. |
14:43 | Type at the command prompt: rmdir space testtree space testtree slash test3 press Enter. |
14:57 | See, it is giving the error message that 'testree' directory cannot be removed because 'testtree' is not empty. |
15:07 | But one thing which you may miss is that testtree slash test3 has been deleted as it was empty. |
15:16 | To check that, type at the command prompt: cd space testtree and press Enter. |
15:25 | Now, type ls and press Enter. See, the directory contains nothing. So, 'test3' was deleted. |
15:34 | 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. |
15:48 | This brings me to the end of this tutorial. Spoken Tutorials are part of the "Talk to a Teacher" project, supported by the National Mission on Education through ICT. |
16:02 | More information on this is available at the following link. |
16:08 | This is Anusha Kadambala, signing off. Thanks for joining. |