Difference between revisions of "BOSS-Linux/C2/File-Attributes/English-timed"

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(Created page with "{| border=1 |'''Time''' |'''Narration''' |- | 00:01 | Welcome to this spoken tutorial on Linux File Attributes. |- | 00:05 | The prerequisite for this tutorial is to create em...")
 
 
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|-
 
|-
 
| 00:01
 
| 00:01
| Welcome to this spoken tutorial on Linux File Attributes.
+
| Welcome to this spoken tutorial on '''Linux File Attributes'''.
 
|-
 
|-
 
| 00:05
 
| 00:05
| The prerequisite for this tutorial is to create empty files named as ''' example1, example2, example3, example4, example5,''' and '''testchown.'''  
+
| The prerequisite for this tutorial is to create empty files named as ''' example1, example2, example3, example4, example5''' and '''testchown.'''  
 
|-
 
|-
 
|00:18
 
|00:18
|Please create empty directories named as '''test_chown''' and '''directory1''' also  
+
|Please create empty directories named as '''test_chown''' and '''directory1''' also.
 
|-
 
|-
 
| 00:25
 
| 00:25
| A file attribute is metadata that describes or is associated with a computer file.  
+
| A '''file attribute''' is '''metadata''' that describes or is associated with a computer file.  
 
|-
 
|-
 
|00:34
 
|00:34
Line 19: Line 19:
 
|-
 
|-
 
| 00:46
 
| 00:46
| c-h own command is used to change the ownership of the file or directory. This is an admin command, root user only can change the owner of a file or directory.  
+
| '''c-h own''' command is used to change the ownership of the file or directory. This is an '''admin command''', '''root''' user only can change the owner of a file or directory.  
 
|-
 
|-
 
| 01:01
 
| 01:01
| The syntax of chown command is '''chown space options space ownername space filename or directoryname '''
+
| The syntax of the '''chown''' command is: '''chown space options space ownername space filename or directoryname'''.
 
|-
 
|-
 
| 01:13
 
| 01:13
| We may give following options with '''chown''' command.  
+
| We may give the following options with '''chown''' command.  
 
|-
 
|-
 
|01:18
 
|01:18
|'''-R''' : To change the permission on files that are in the subdirectories of the directory that you are currently in.  
+
|'''-R''' : To change the '''permission''' on files that are in the sub-directories of the directory that you are currently in.  
 
|-
 
|-
 
|01:28
 
|01:28
Line 34: Line 34:
 
|-
 
|-
 
|01:32
 
|01:32
|'''-f''' : Prevents ch own from displaying error messages.  
+
|'''-f''' : Prevents '''ch own''' from displaying error messages.  
 
|-
 
|-
 
| 01:37
 
| 01:37
| Now we will look at some examples  
+
| Now, we will look at some examples.
 
|-
 
|-
 
| 01:41
 
| 01:41
| So go to the terminal. We will move to the directory where we have created empty files and folders. For that '''cd space Desktop slash file attribute''' and press enter
+
| So, go to the terminal. We will move to the directory where we have created empty files and folders. For that, '''cd space Desktop slash file attribute''' and press '''Enter'''.
 
|-
 
|-
 
| 01:56
 
| 01:56
| Now type the command '''ls space -l space testchown''' that is t-e-s-t-c-h-o-w-n and press Enter.
+
| Now type the command: '''ls space -l space testchown''' that is t-e-s-t-c-h-o-w-n and press '''Enter'''.
 
|-
 
|-
 
| 02:11
 
| 02:11
| Here we can see the owner of the file '''testchown''' is '''shahid'''
+
| Here we can see the owner of the '''testchown''' is "shahid".
 
|-
 
|-
 
| 02:18
 
| 02:18
| To change the owner of the file, type the command '''sudo space c-h own space that is a-n-u-s-h-a anusha space testchown''' that is t-e-s-t-c-h-o-w-n. press Enter  
+
| To change the '''owner''' of the file, type the command '''sudo space c-h own space a-n-u-s-h-a anusha space testchown''' that is t-e-s-t-c-h-o-w-n and press '''Enter'''.
  
 
|-
 
|-
 
| 02:36
 
| 02:36
| Enter the '''sudo''' password and press Enter again. Press enter
+
| Enter the '''sudo''' password and press '''Enter''' again. Press '''Enter'''.
 
|-
 
|-
 
| 02:44
 
| 02:44
| Now type '''ls space -l space t-e-s-t-c-h-o-w-n''' and press Enter  
+
| Now type: '''ls space -l space t-e-s-t-c-h-o-w-n''' and press '''Enter'''. Here, we can see the new owner of the file is "anusha".
Here we can see the new owner of the file is anusha.
+
 
|-
 
|-
 
| 03:03
 
| 03:03
| Now we will see how to change owner of the directory  
+
| Now we will see how to change owner of the directory.
 
|-
 
|-
 
|03:07
 
|03:07
|Type the command ''' ls space -l''' and  press Enter  
+
|Type the command: ''' ls space -l''' and  press '''Enter'''. Here we can see the owner of the directory '''test_chown''' is "shahid".
Here we can see the owner of the directory '''test_chown''' is shahid  
+
 
|-
 
|-
 
| 03:22
 
| 03:22
| To change the owner of the directory, type the command  
+
| To change the owner of the directory, type the command:
 
|-
 
|-
 
|03:26
 
|03:26
|'''sudo space chown space minus capital R space a-n-u-s-h-a anusha space test_chown''' which is directory name and press Enter  
+
|'''sudo space chown space minus capital R space a-n-u-s-h-a anusha space test_chown''' which is directory name and press '''Enter'''.
 
|-
 
|-
 
|03:44
 
|03:44
|Enter the sudo password, if required and press Enter again.  
+
|Enter the sudo password, if required, and press '''Enter''' again.  
  
 
|-
 
|-
 
| 03:49
 
| 03:49
| I will clear the screen by pressing Clt+L for our convenience. Now type '''ls space -l'''  press Enter  
+
| I will clear the screen by pressing '''Clt+L''' for our convenience. Now type: '''ls space -l'''  and press '''Enter'''. Here we can see the new owner of the directory is "anusha".  
Here we can see the new owner of the directory is anusha.  
+
 
|-
 
|-
 
| 04:06
 
| 04:06
| '''chmod''' command is used to change the access mode or permissions of one or more files.  
+
| '''chmod''' command is used to change the '''access mode''' or '''permissions''' of one or more files.  
 
|-
 
|-
 
| 04:13
 
| 04:13
| Syntax of the '''chmod''' command is  '''chmod space [options] space mode space filename space chmod space [options] space filename'''
+
| Syntax of the '''chmod''' command is: '''chmod space [options] space mode space filename'''
 
+
We may give the following options with the chmod command-
We may give the following options with chmod command.
+
 
|-
 
|-
 
|04:29
 
|04:29
Line 95: Line 91:
 
|-
 
|-
 
| 04:41
 
| 04:41
| There are following types of access or permissions  
+
| There are following types of '''access''' or '''permissions'''-
 
|-
 
|-
 
|04:44
 
|04:44
|r that is Read  
+
|r: that is Read  
  
w that is Write  
+
w: that is Write  
  
x that is Execute  
+
x: that is Execute  
  
s that is Set user (or group) ID  
+
s: that is Set user (or group) ID.
 
|-
 
|-
 
| 04:54
 
| 04:54
| Alternatively, we may specify permissions by a three-digit octal number.  
+
| Alternatively, we may specify permissions by a three-digit octal-number.  
 
|-
 
|-
 
|05:00
 
|05:00
|The first digit stands for owner permission, the second stands for group permission, and the third stands for other's permission.
+
|The first digit stands for '''owner permission''', the second stands for '''group permission''' and the third stands for other permission.
 
|-
 
|-
 
| 05:09
 
| 05:09
| Permissions are calculated by adding the following octal values:
+
| Permissions are calculated by adding the following octal values-
4 that is Read  
+
4: that is Read  
  
2 that is Write  
+
2: that is Write  
  
1 that is Execute  
+
1: that is Execute.
 
|-
 
|-
 
| 05:20
 
| 05:20
| Now we will look at some examples of '''chmod'''. Move to terminal and enter the command to add execute-by-user permission to file '''example1.'''
+
| Now we will look at some examples of '''chmod'''. Move to terminal and enter the command to add '''execute-by-user''' permission to file '''example1.'''
 
|-
 
|-
 
|05:30
 
|05:30
| Before that i will again clear the screen by pressing Clt+l.
+
| Before that I will again clear the screen by pressing '''Clt+l'''.
 
|-
 
|-
 
  | 05:36
 
  | 05:36
| Now lets type '''chmod space u+x space example1 ''' press Enter  
+
| Now, let's type '''chmod space u+x space example1 ''' press '''Enter'''.
  
 
|-
 
|-
 
| 05:49
 
| 05:49
| Now type '''ls space -l space example1 '''
+
| Now, type: '''ls space -l space example1 '''
press Enter to see the changes  
+
press '''Enter''' to see the changes.
 
|-
 
|-
 
|06:01
 
|06:01
|Here you can see to assign the '''read/write/execute''' permission by owner, ''' read/execute''' permission by group, and execute-only permission by others to file '''example1'''
+
|Here, you can see to assign the '''read/write/execute''' permission by owner, ''' read/execute''' permission by group, and '''execute-only''' permission by others to file 'example1'.
 
|-
 
|-
 
| 06:15
 
| 06:15
| Now type the command '''chmod space 751 space example1 '''
+
| Now type the command: '''chmod space 751 space example1 '''press '''Enter'''.
press Enter  
+
 
|-
 
|-
 
| 06:26
 
| 06:26
| Now type ''' ls space -l space example1 ''' and press Enter  
+
| Now type: ''' ls space -l space example1 ''' and press '''Enter'''.
 
|-
 
|-
 
|06:35
 
|06:35
|Here we can see that above command has assigned the '''read/write/execute''' permission by owner, '''read/execute''' permission by group, and execute-only permission by others to file example1.  
+
|Here we can see that above command has assigned the '''read/write/execute''' permission by owner, '''read/execute''' permission by group and '''execute-only''' permission by others to file example1.  
 
|-
 
|-
 
| 06:52
 
| 06:52
| To assign read-only permission to file '''example1''' for everyone type the command ''' chmod space =r space example1 '''
+
| To assign '''read-only''' permission to file '''example1''' for everyone, type the command: ''' chmod space =r space example1 '''and press '''Enter'''.
and press Enter  
+
 
|-
 
|-
 
| 07:08
 
| 07:08
| Now type the command '''ls space -l space example1'''
+
| Now type the command: '''ls space -l space example1''' press '''Enter'''.
press Enter  
+
 
|-
 
|-
 
|07:19
 
|07:19
|Here we can see that the '''read only''' permission has been assigned to file '''example1''' for everyone  
+
|Here we can see that the '''read only''' permission has been assigned to file 'example1' for everyone.
 
|-
 
|-
 
| 07:30
 
| 07:30
| To change the permission recursively and assign the read and execute access for everyone and also write access for the owner of the directory '''directory1''' type the command  
+
| To change the permission recursively and assign the '''read''' and '''execute''' access for everyone and also '''write''' access for the owner of the directory 'directory1', type the command:
 
|-
 
|-
|7:44
+
|07:44
|'''chmod space minus capital R space 755 space directory1 '''
+
|'''chmod space minus capital R space 755 space directory1 '''press '''Enter'''.
press Enter  
+
 
|-
 
|-
 
| 08:00
 
| 08:00
| Now type ''' ls space -l ''' press Enter to see the changes  
+
| Now type: ''' ls space -l ''' press '''Enter''' to see the changes.
 
+
 
+
 
|-
 
|-
 
| 08:09
 
| 08:09
| To give the user execute permission on file '''example2''' Type the command  
+
| To give the user execute permission on file 'example2', type the command:
''' chmod space u+x space example2 ''' press Enter  
+
''' chmod space u+x space example2 ''' press '''Enter'''.
 
|-
 
|-
 
| 08:27
 
| 08:27
| Now type the command ''' ls space -l space example2 ''' and press Enter  
+
| Now type the command: ''' ls space -l space example2 ''' and press '''Enter'''.
 
|-
 
|-
 
|08:40
 
|08:40
|Here we can see that execute permission has been assigned to user on '''example2'''
+
|Here, we can see that '''execute''' permission has been assigned to user on 'example2'.
 
|-
 
|-
 
| 08:50
 
| 08:50
| To add the write permissions to the group for file '''example3''', type the command  
+
| To add the '''write''' permissions to the group for file 'example3', type the command: '''chmod space g+w space example3'''. Press '''Enter'''.
'''chmod space g+w space example3'''. Press Enter  
+
 
|-
 
|-
 
| 09:10
 
| 09:10
| and now type ''' ls space -l space example3 ''' press Enter  
+
| And now, type: ''' ls space -l space example3 ''' press '''Enter'''.
 
|-
 
|-
 
|09:24
 
|09:24
|Here we can see the write permission has been added to group  
+
|Here we can see the '''write''' permission has been added to '''group'''.
 
|-
 
|-
 
| 09:30
 
| 09:30
| To remove the write permissions for all type the command ''' chmod space a-w space example3 '''
+
| To remove the '''write''' permissions for all, type the command: ''' chmod space a-w space example3''' press '''Enter'''.
press Enter  
+
 
|-
 
|-
 
| 09:45
 
| 09:45
| Now type ''' ls space -l space example3 ''' press Enter  
+
| Now type: ''' ls space -l space example3 ''' press '''Enter'''.
 
|-
 
|-
 
|09:55
 
|09:55
|Here we can see the write permission for all has been removed  
+
|Here we can see the '''write''' permission for all has been removed.
 
|-
 
|-
 
| 10:02
 
| 10:02
| '''chgrp''' command is used to change the group of one or more files to newgroup.  
+
| '''chgrp''' command is used to change the group of one or more files to new group.  
 
|-
 
|-
 
|10:10
 
|10:10
|Newgroup is either a group ID number or a group name located in '''/etc/group. '''
+
|New group is either a group ID number or a group name located in '''/etc/group. '''
 
|-
 
|-
 
|10:20
 
|10:20
Line 210: Line 198:
 
|-
 
|-
 
| 10:26
 
| 10:26
| The syntax for the chgrp command is '''chgrp space [options] space newgroup space files.'''
+
| The syntax for the '''chgrp''' command is: '''chgrp space [options] space newgroup space files.'''
 
|-
 
|-
 
| 10:36
 
| 10:36
| Lets go to terminal. Now we will look at some examples of '''chgrp''' command.
+
| Let's go to terminal. Now we will look at some examples of '''chgrp''' command.
type the command  '''ls space -l space example4''' press Enter  
+
Type the command  '''ls space -l space example4''' press Enter.
 
|-
 
|-
 
|10:57
 
|10:57
|Here we can see the group permission is for user '''shahid '''
+
|Here we can see the group permission is for user "shahid".
 
|-
 
|-
 
| 11:03
 
| 11:03
| To change the group permission , type the command '''sudo space chgrp space rohit space example4'''
+
| To change the '''group''' permission, type the command: '''sudo space chgrp space rohit space example4'''.
 
|-
 
|-
 
|11:20
 
|11:20
|press Enter. Enter the sudo password if required.  
+
|Press Enter. Enter the 'sudo' password if required.  
 
|-
 
|-
 
| 11:27
 
| 11:27
| Now type the command ''' ls space -l space example4 '''
+
| Now type the command: ''' ls space -l space example4 '''. Press Enter.
press Enter  
+
 
|-
 
|-
 
|11:38
 
|11:38
|Here we can see that the group has changed from shahid to rohit.  
+
|Here we can see that the '''group''' has changed from "shahid" to "rohit".  
 
|-
 
|-
 
| 11:46
 
| 11:46
| The inode number is a unique integer assigned to the device.
+
| The inode-number is a unique integer assigned to a device.
 
|-
 
|-
 
|11:51
 
|11:51
| Inode stores basic information about a regular file or a directory.  
+
| '''Inode''' stores basic information about a regular file or a directory.  
 
|-
 
|-
 
|11:57
 
|11:57
|All the files are hard links to inodes.  
+
|All the files are hard-links to inodes.  
 
|-
 
|-
 
|12:00
 
|12:00
|Whenever a program refers to a file by name, the system actually uses the filename to search for the corresponding '''inode. '''
+
|Whenever a program refers to a file by name, the system actually uses the filename to search for the corresponding '''inode.'''
 
|-
 
|-
 
| 12:12
 
| 12:12
| We can use ''' ls space -i''' command to see the '''inode''' number of a file.  
+
| We can use ''' ls space -i''' command to see the '''inode'''-number of a file.  
 
|-
 
|-
 
|12:19
 
|12:19
|type the command ''' ls space -i space example5 ''' press Enter  
+
|Type the command: ''' ls space -i space example5 ''' press Enter.
 
|-
 
|-
 
|12:29
 
|12:29
|Number written before the file is the inode number of the file.  
+
|Number written before the file is the inode-number of the file.  
 
|-
 
|-
 
| 12:35
 
| 12:35
Line 257: Line 244:
 
|-
 
|-
 
|12:41
 
|12:41
|Hard links are to associate multiple directory entries with a single '''inode.'''  
+
|'''Hard links''' are to associate multiple directory entries with a single '''inode.''' '''ln''' is the command to make link.
'''ln''' is the command to make link  
+
 
|-
 
|-
 
| 12:52
 
| 12:52
| The syntax of '''ln''' command to create the hard link is  
+
| The syntax of '''ln''' command to create the hard link is:
 
|-
 
|-
 
|12:57
 
|12:57
|'''ln space source space link ''' where, '''source''' is an existing file and '''link''' is the file to create.
+
|'''ln space source space link ''' where '''source''' is an existing file and '''link''' is the file to create.
 
|-
 
|-
 
| 13:06
 
| 13:06
| Now we will look at some examples of hard links  
+
| Now we will look at some examples of hard-links.
 
|-
 
|-
 
|13:10
 
|13:10
|Let me clear the screen again. Now type the command '''ln space example1 space exampleln''' press Enter  
+
|Let me clear the screen again. Now type the command: '''ln space example1 space exampleln''' press Enter.
 
|-
 
|-
 
| 13:25
 
| 13:25
| To display the '''inode''' number of both the files, type the command  
+
| To display the '''inode''' number of both the files, type the command:
  
'''ls space -i space example1 space exampleln '''press Enter  
+
'''ls space -i space example1 space exampleln '''press Enter.
 
|-
 
|-
 
|13:41
 
|13:41
|Here we can see that inode number of both the files are same, file exampleln is the hard link for file example1  
+
|Here we can see that inode number of both the files are same; file 'exampleln' is the hard-link for file 'example1'.
 
|-
 
|-
 
| 13:54
 
| 13:54
| Soft link symbolic link is a special type of file that contains a reference to another file or directory in the form of an absolute or relative path.  
+
| '''Soft-link''' i.e. '''symbolic link''' is a special type of file that contains a reference to another file or directory in the form of an '''absolute''' or '''relative path'''.  
 
|-
 
|-
 
| 14:07
 
| 14:07
| The syntax of '''ln''' command to create soft links is  
+
| The syntax of '''ln''' command to create soft links is:
 
|-
 
|-
 
|14:12
 
|14:12
|''' ln space -s space {target-filename} space {symbolic-filename} '''
+
|''' ln space -s space {target-filename} space {symbolic-filename}'''.
 
|-
 
|-
 
| 14:19
 
| 14:19
| Now we will look at some examples of soft link  
+
| Now we will look at some examples of soft-link.
 
|-
 
|-
 
| 14:25
 
| 14:25
| To create the soft link, type the command '''ln space -s space example1 space examplesoft '''
+
| To create the soft-link, type the command: '''ln space -s space example1 space examplesoft '''.
 
|-
 
|-
 
|14:40
 
|14:40
|press Enter  
+
|Press Enter.
 
|-
 
|-
 
| 14:43
 
| 14:43
| Now, to display the '''inode''' number and list of both the files, type the command  
+
| Now, to display the '''inode''' number and list of both the files, type the command:
''' ls space -li space example1 space examplesoft '''
+
'''ls space -li space example1 space examplesoft'''.
 
|-
 
|-
 
|15:01
 
|15:01
|press Enter  
+
|Press Enter.
 
|-
 
|-
 
|15:03
 
|15:03
|Here we can see that '''inode''' number of both the files are different and examplesoft is a softlink of example1.  
+
|Here we can see that '''inode''' number of both the files are different and 'examplesoft' is a soft-link of 'example1'.  
 
|-
 
|-
 
| 15:16
 
| 15:16
| So in this tutorial we have learnt about the Linux Files Attributes like changing permission, ownership and group of a file.  
+
| So, in this tutorial we have learnt about the '''Linux Files Attributes''' like changing permission, ownership and group of a file.  
 
|-
 
|-
 
|15:26
 
|15:26
|We also learnt about the inode, soft and hard links of a file.
+
|We also learnt about the inode, soft and hard-links of a file.
 
|-
 
|-
 
|15:31
 
|15:31
Line 318: Line 304:
 
|-
 
|-
 
|15:35
 
|15:35
|Spoken Tutorials are a part of the Talk to a Teacher project, supported by the National Mission on Education through ICT.  
+
|Spoken Tutorials are a part of the "Talk to a Teacher" project, supported by the National Mission on Education through ICT.  
 
|-
 
|-
 
|15:44
 
|15:44

Latest revision as of 11:59, 24 March 2017

Time Narration
00:01 Welcome to this spoken tutorial on Linux File Attributes.
00:05 The prerequisite for this tutorial is to create empty files named as example1, example2, example3, example4, example5 and testchown.
00:18 Please create empty directories named as test_chown and directory1 also.
00:25 A file attribute is metadata that describes or is associated with a computer file.
00:34 File attribute is the characteristics that describe a file, such as owner, file type, access permissions, etc.
00:46 c-h own command is used to change the ownership of the file or directory. This is an admin command, root user only can change the owner of a file or directory.
01:01 The syntax of the chown command is: chown space options space ownername space filename or directoryname.
01:13 We may give the following options with chown command.
01:18 -R : To change the permission on files that are in the sub-directories of the directory that you are currently in.
01:28 -c : Change the permission for each file.
01:32 -f : Prevents ch own from displaying error messages.
01:37 Now, we will look at some examples.
01:41 So, go to the terminal. We will move to the directory where we have created empty files and folders. For that, cd space Desktop slash file attribute and press Enter.
01:56 Now type the command: ls space -l space testchown that is t-e-s-t-c-h-o-w-n and press Enter.
02:11 Here we can see the owner of the testchown is "shahid".
02:18 To change the owner of the file, type the command sudo space c-h own space a-n-u-s-h-a anusha space testchown that is t-e-s-t-c-h-o-w-n and press Enter.
02:36 Enter the sudo password and press Enter again. Press Enter.
02:44 Now type: ls space -l space t-e-s-t-c-h-o-w-n and press Enter. Here, we can see the new owner of the file is "anusha".
03:03 Now we will see how to change owner of the directory.
03:07 Type the command: ls space -l and press Enter. Here we can see the owner of the directory test_chown is "shahid".
03:22 To change the owner of the directory, type the command:
03:26 sudo space chown space minus capital R space a-n-u-s-h-a anusha space test_chown which is directory name and press Enter.
03:44 Enter the sudo password, if required, and press Enter again.
03:49 I will clear the screen by pressing Clt+L for our convenience. Now type: ls space -l and press Enter. Here we can see the new owner of the directory is "anusha".
04:06 chmod command is used to change the access mode or permissions of one or more files.
04:13 Syntax of the chmod command is: chmod space [options] space mode space filename

We may give the following options with the chmod command-

04:29 -c : Print information about files that are changed.
04:34 -f : Do not notify user of files that chmod cannot change.
04:41 There are following types of access or permissions-
04:44 r: that is Read

w: that is Write

x: that is Execute

s: that is Set user (or group) ID.

04:54 Alternatively, we may specify permissions by a three-digit octal-number.
05:00 The first digit stands for owner permission, the second stands for group permission and the third stands for other permission.
05:09 Permissions are calculated by adding the following octal values-

4: that is Read

2: that is Write

1: that is Execute.

05:20 Now we will look at some examples of chmod. Move to terminal and enter the command to add execute-by-user permission to file example1.
05:30 Before that I will again clear the screen by pressing Clt+l.
05:36 Now, let's type chmod space u+x space example1 press Enter.
05:49 Now, type: ls space -l space example1

press Enter to see the changes.

06:01 Here, you can see to assign the read/write/execute permission by owner, read/execute permission by group, and execute-only permission by others to file 'example1'.
06:15 Now type the command: chmod space 751 space example1 press Enter.
06:26 Now type: ls space -l space example1 and press Enter.
06:35 Here we can see that above command has assigned the read/write/execute permission by owner, read/execute permission by group and execute-only permission by others to file example1.
06:52 To assign read-only permission to file example1 for everyone, type the command: chmod space =r space example1 and press Enter.
07:08 Now type the command: ls space -l space example1 press Enter.
07:19 Here we can see that the read only permission has been assigned to file 'example1' for everyone.
07:30 To change the permission recursively and assign the read and execute access for everyone and also write access for the owner of the directory 'directory1', type the command:
07:44 chmod space minus capital R space 755 space directory1 press Enter.
08:00 Now type: ls space -l press Enter to see the changes.
08:09 To give the user execute permission on file 'example2', type the command:

chmod space u+x space example2 press Enter.

08:27 Now type the command: ls space -l space example2 and press Enter.
08:40 Here, we can see that execute permission has been assigned to user on 'example2'.
08:50 To add the write permissions to the group for file 'example3', type the command: chmod space g+w space example3. Press Enter.
09:10 And now, type: ls space -l space example3 press Enter.
09:24 Here we can see the write permission has been added to group.
09:30 To remove the write permissions for all, type the command: chmod space a-w space example3 press Enter.
09:45 Now type: ls space -l space example3 press Enter.
09:55 Here we can see the write permission for all has been removed.
10:02 chgrp command is used to change the group of one or more files to new group.
10:10 New group is either a group ID number or a group name located in /etc/group.
10:20 Only the owner of a file or a privileged user may change the group.
10:26 The syntax for the chgrp command is: chgrp space [options] space newgroup space files.
10:36 Let's go to terminal. Now we will look at some examples of chgrp command.

Type the command ls space -l space example4 press Enter.

10:57 Here we can see the group permission is for user "shahid".
11:03 To change the group permission, type the command: sudo space chgrp space rohit space example4.
11:20 Press Enter. Enter the 'sudo' password if required.
11:27 Now type the command: ls space -l space example4 . Press Enter.
11:38 Here we can see that the group has changed from "shahid" to "rohit".
11:46 The inode-number is a unique integer assigned to a device.
11:51 Inode stores basic information about a regular file or a directory.
11:57 All the files are hard-links to inodes.
12:00 Whenever a program refers to a file by name, the system actually uses the filename to search for the corresponding inode.
12:12 We can use ls space -i command to see the inode-number of a file.
12:19 Type the command: ls space -i space example5 press Enter.
12:29 Number written before the file is the inode-number of the file.
12:35 Inodes are associated with precisely one directory at a time.
12:41 Hard links are to associate multiple directory entries with a single inode. ln is the command to make link.
12:52 The syntax of ln command to create the hard link is:
12:57 ln space source space link where source is an existing file and link is the file to create.
13:06 Now we will look at some examples of hard-links.
13:10 Let me clear the screen again. Now type the command: ln space example1 space exampleln press Enter.
13:25 To display the inode number of both the files, type the command:

ls space -i space example1 space exampleln press Enter.

13:41 Here we can see that inode number of both the files are same; file 'exampleln' is the hard-link for file 'example1'.
13:54 Soft-link i.e. symbolic link is a special type of file that contains a reference to another file or directory in the form of an absolute or relative path.
14:07 The syntax of ln command to create soft links is:
14:12 ln space -s space {target-filename} space {symbolic-filename}.
14:19 Now we will look at some examples of soft-link.
14:25 To create the soft-link, type the command: ln space -s space example1 space examplesoft .
14:40 Press Enter.
14:43 Now, to display the inode number and list of both the files, type the command:

ls space -li space example1 space examplesoft.

15:01 Press Enter.
15:03 Here we can see that inode number of both the files are different and 'examplesoft' is a soft-link of 'example1'.
15:16 So, in this tutorial we have learnt about the Linux Files Attributes like changing permission, ownership and group of a file.
15:26 We also learnt about the inode, soft and hard-links of a file.
15:31 This brings me to the end of this tutorial.
15:35 Spoken Tutorials are a part of the "Talk to a Teacher" project, supported by the National Mission on Education through ICT.
15:44 More information on the same is available at the following link.
15:50 This script is contributed by Anusha Ambala and Shahid. Thanks or joining.

Contributors and Content Editors

PoojaMoolya, Pratik kamble, Pravin1389, Sandhya.np14