Difference between revisions of "Linux/C2/File-Attributes/English-timed"
From Script | Spoken-Tutorial
PoojaMoolya (Talk | contribs) |
|||
| (8 intermediate revisions by 3 users not shown) | |||
| Line 2: | Line 2: | ||
|'''Time''' | |'''Time''' | ||
|'''Narration''' | |'''Narration''' | ||
| + | |||
|- | |- | ||
| 00:00 | | 00:00 | ||
| − | | Welcome to this spoken tutorial on Linux File Attributes. | + | | Welcome to this spoken tutorial on '''Linux''' '''File Attributes'''. |
| + | |||
|- | |- | ||
| 00:05 | | 00:05 | ||
| − | | The | + | | The prerequisites 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. |
| + | |||
|- | |- | ||
|00:33 | |00:33 | ||
| − | |File attribute is the characteristics that | + | |File attribute is the characteristics that describes a file such as owner, file type, access permissions etc. |
| + | |||
|- | |- | ||
| 00:45 | | 00:45 | ||
| − | | 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. |
| + | |||
|- | |- | ||
| 01:00 | | 01:00 | ||
| − | | The syntax of chown command is '''<nowiki>chown space options space ownername space filename or directoryname </nowiki>''' | + | | The syntax of '''chown''' command is '''<nowiki>chown space options space ownername space filename or directoryname </nowiki>''' |
| + | |||
|- | |- | ||
| 01:13 | | 01:13 | ||
| − | | We may give following options with chown command. | + | | We may give following options with '''chown''' command. |
| + | |||
|- | |- | ||
|01:18 | |01:18 | ||
| − | |'''-R''' : To change the permission on files that are in the | + | |'''-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 | ||
|'''-c ''': Change the permission for each file. | |'''-c ''': Change the permission for each file. | ||
| + | |||
|- | |- | ||
|01:33 | |01:33 | ||
| − | |'''-f''' : Prevents | + | |'''-f''' : Prevents '''chown''' from displaying error messages. |
| + | |||
|- | |- | ||
| 01:37 | | 01:37 | ||
| − | | Now we will look at some examples | + | | Now we will look at some examples. |
| + | |||
|- | |- | ||
| 01:40 | | 01:40 | ||
| − | | 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 | + | | 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 | + | | Now type the command: $ ls space -l space testchown that is t-e-s-t-c-h-o-w-n and press Enter. |
| − | $ ls space -l | + | |
|- | |- | ||
| 02:11 | | 02:11 | ||
| − | | Here we can see the owner of the file 'testchown' is shahid | + | | Here we can see the owner of the file 'testchown' is shahid. |
| + | |||
|- | |- | ||
| 02:18 | | 02:18 | ||
| − | | To change the owner of the file, type the command | + | | 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 |
| − | $ 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. |
| − | + | ||
|- | |- | ||
| 02:36 | | 02:36 | ||
| − | | Enter the sudo password and press Enter again. Press | + | | Enter the sudo password and press Enter again. Press Enter. |
| + | |||
|- | |- | ||
| 02:44 | | 02:44 | ||
| − | | Now type | + | | 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. |
| − | and press Enter | + | |
| − | 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 -l and press Enter | + | | Type the command: $ ls -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 | + | |
|- | |- | ||
| 03:21 | | 03:21 | ||
| − | | 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 | + | | $ 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. |
| − | and press Enter | + | |
| − | + | ||
| − | + | ||
| − | + | ||
|- | |- | ||
| + | | 03:44 | ||
| + | | Enter the sudo password if required and press Enter again. | ||
| + | |- | ||
| 03:49 | | 03:49 | ||
| − | | I will clear the screen by pressing | + | | I will clear the screen by pressing '''Ctrl+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 | + | | Syntax of the '''chmod''' command is chmod space [options] space mode space filename We may give the following options with '''chmod''' command. |
| − | + | ||
| − | |||
|- | |- | ||
| − | |04:29 | + | | 04:29 |
| − | | | + | |''' -c''' : Print information about files that are changed. |
| + | |||
|- | |- | ||
|04:34 | |04:34 | ||
| − | | | + | |'''-f '''': Do not notify user of files that '''chmod''' cannot change. |
| + | |||
|- | |- | ||
| 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 : Read | + | |r : Read, w : Write, x : Execute, s : 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 | + | |The first digit stands for owner permission, the second stands for group permission, and the third stands for others 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 2 that is Write 1 that is Execute |
| − | 4 that is Read | + | |
| − | |||
| − | |||
| − | |||
|- | |- | ||
| 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 | + | | Before that, I will again clear the screen by pressing '''Ctrl+l'''. |
| + | |||
|- | |- | ||
| − | + | | 05:36 | |
| − | | Now | + | | Now, let's type: $ chmod space u+x space example1 press Enter. |
| − | $ chmod space u+x space example1 | + | |
| − | press Enter | + | |
|- | |- | ||
| − | + | | 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. |
| + | |||
|- | |- | ||
| 06:15 | | 06:15 | ||
| − | | Now type the command | + | | Now type the command: $ chmod space 751 space example1 press Enter. |
| − | press Enter | + | |
|- | |- | ||
| 06:26 | | 06:26 | ||
| − | | Now type | + | | Now type: $ ls space -l space example1 and press Enter. |
| − | $ 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 <nowiki>=r space </nowiki>example1 | + | | To assign read-only permission to file example1 for everyone, type the command: $ chmod space <nowiki>=r space </nowiki>example1 |
| − | and press Enter | + | and press Enter. |
| + | |||
|- | |- | ||
| 07:08 | | 07:08 | ||
| − | | Now type the command | + | | 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: |
| + | |||
|- | |- | ||
| − | | | + | |07:44 |
| − | |$ chmod space minus capital R space 755 space directory1 | + | |$ chmod space minus capital R space 755 space directory1. Press Enter. |
| − | + | ||
|- | |- | ||
| 08:00 | | 08:00 | ||
| − | | Now type | + | | Now type: $ ls space -l press Enter to see the changes. |
| − | $ ls space -l | + | |
| − | press Enter to see the changes | + | |
| − | + | ||
|- | |- | ||
| 08:09 | | 08:09 | ||
| − | | To give the user execute permission on file example2 | + | | 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 | + | | Now type the command: $ ls space -l space example2 and press Enter. |
| − | $ 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 | | To add the write permissions to the group for file example3 | ||
| − | type the command | + | |
| − | $ chmod space g+w space example3 | + | type the command: $ chmod space g+w space example3. Press Enter. |
| − | + | ||
|- | |- | ||
| 09:10 | | 09:10 | ||
| − | | and now type | + | | and now type: $ ls space -l space example3 press Enter. |
| − | $ ls space -l space example3 | + | |
| − | press Enter | + | |
|- | |- | ||
|09:23 | |09:23 | ||
| − | |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 | + | | To remove the write permissions for all, type the command: $ chmod space a-w space example3 |
| − | $ chmod space a-w space example3 | + | |
| − | + | Press Enter. | |
| + | |||
|- | |- | ||
| 09:45 | | 09:45 | ||
| − | | Now type | + | | Now, type: $ ls space -l space example3 press Enter. |
| − | $ 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 | + | | '''chgrp''' command is used to change the group of one or more files to new group. |
| + | |||
|- | |- | ||
|10:10 | |10:10 | ||
| − | | | + | |New group is either a group ID number or a group name located in /etc/group. |
| + | |||
|- | |- | ||
|10:20 | |10:20 | ||
|Only the owner of a file or a privileged user may change the group. | |Only the owner of a file or a privileged user may change the group. | ||
| + | |||
|- | |- | ||
| 10:26 | | 10:26 | ||
| − | | The syntax for the chgrp command is | + | | The syntax for the '''chgrp''' command is chgrp space [options] space newgroup space files. |
| − | + | ||
|- | |- | ||
| 10:36 | | 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 | |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. |
| − | 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. |
| − | + | ||
|- | |- | ||
|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 the 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. |
| − | + | ||
|- | |- | ||
|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 | ||
| − | | Inodes are associated with precisely one directory at a time. | + | | 'Inodes' are associated with precisely one directory at a time. |
| + | |||
|- | |- | ||
|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 | + | |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 | + | |Let me clear the screen again. Now type the command: $ ln space example1 space exampleln press Enter. |
| − | $ 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. |
| − | |||
| − | |||
|- | |- | ||
|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''' '''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 | + | | To create the soft-link, type the command: $ ln space -s space example1 space examplesoft |
| − | $ 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 | + | |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 | ||
| This brings me to the end of this tutorial. | | This brings me to the end of this tutorial. | ||
| + | |||
|- | |- | ||
|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 | ||
|More information on the same is available at the following link. | |More information on the same is available at the following link. | ||
| + | |||
|- | |- | ||
|15:50 | |15:50 | ||
| 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. | | 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. | ||
|} | |} | ||
Latest revision as of 16:58, 23 March 2017
| Time | Narration |
| 00:00 | Welcome to this spoken tutorial on Linux File Attributes. |
| 00:05 | The prerequisites 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. |
| 00:33 | File attribute is the characteristics that describes a file such as owner, file type, access permissions etc. |
| 00:45 | '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. |
| 01:00 | The syntax of chown command is chown space options space ownername space filename or directoryname |
| 01:13 | We may give 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. |
| 01:33 | -f : Prevents chown from displaying error messages. |
| 01:37 | Now we will look at some examples. |
| 01:40 | 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 file 'testchown' is shahid. |
| 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. |
| 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 -l and press Enter. Here we can see the owner of the directory 'test_chown' is shahid. |
| 03:21 | 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 Ctrl+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 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 : Read, w : Write, x : Execute, s : 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 others 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 Ctrl+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. |
| 09:23 | 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 the 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 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 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. |
