What command is used on Linux in order to change the group of a file or directory?
Linux chgrp Command | Linux Change GroupLinux chgrp command is used to change the group ownership of a file or directory. In the Linux file system, each file is related to corresponding owner and group, and has read, write, and execute permission. Show
Syntax:Options:The chgrp command supports the following command-line options: -c, --changes: It is like 'verbose' option but, it is reported only when a change is made. -f, --silent, --quiet: It is used to suppress most error messages. -v, --verbose: It is used to display a diagnostic for every file processed. --dereference: It is used to affect each symbolic link's significance, rather than the symbolic link itself. -h, --no-dereference: It is used to alter the symbolic links instead of any referenced file --no-preserve-root: It is used for not treating the '/' especially. --preserve-root: It is used when the default command is failed to operate recursively on '/.' --reference=RFILE: It is used to use RFILE's group rather than a specific group. -R, --recursive: It is used to operate on files and directories recursively. The option specifies the traversing of the '-R' option. -H: It is used to traverse a symbolic link to a directory. -L: It is used to traverse every symbolic link to a directory encountered. -P: If this option is specified, it will not traverse any symbolic links (default) --help: It is used to display the help manual having the brief information of supported command-line options. --version: It is used to display version information. Examples of the chgrp CommandLet's see the following examples of the chgrp command:
Change the Group Ownership of a FileWe can change the group of any specific file. To change the group ownership of a file, execute the command as follows: The above command will change the group of file 'Demo1.txt' to Javatpoint. Consider the below output: As we can see from the above output, the 'groups' command is used to list the available groups in the system. And, the 'chgrp' command executed with the sudo because it needs sudo privilege. Change the group ownership of a folderTo change the group ownership of a folder, execute the 'chgrp' command with the folder name as follows: The above command will change the group ownership of the 'Newdirectory' folder. Consider the below output: If the chgrp command is successfully executed, it will not produce any output. To confirm the changes, execute the "ls -l" command. Recursively change the group ownership of a folder and its contentWe can change the group ownership of a file or folder recursively by applying some set of rules. To recursively change the group ownership of a folder and its content, execute the command as follows: Consider the below output: Change group by using the group name of a reference fileWe can change the group of a file by using the group name of a reference file. To change the group of another file using the reference of any other file or directory, execute the command as follows: The above command will change the group of 'ref.txt' by using the reference of 'Nwdirectory.' Consider the below output: Changing the Owner, Group, and PermissionsAs we said, most of the time you can get by with the default security the system gives you. But there are always exceptions, particularly for system administrators. To take a simple example, suppose you are creating a directory under Similarly, there are certain utilities such as UUCP and News that have their own users. No one ever logs in as UUCP or News, but those users and groups must exist so that the utilities can do their job in a secure manner. In general, the last step when installing software is usually to change the owner, group, and permissions as the documentation tells you to do. The chown command changes the owner of a file, and the chgrp command changes the group. On Linux, only root can use chown for changing ownership of a file, but any user can change the group to another group he belongs to. So after installing some software named # You could also do this in one step by using the dot notation: # The syntax for changing permissions is more complicated. The permissions can also be called the file’s “mode,” and the command that changes permissions is
chmod. Let’s start our exploration of this command through a simple example; say you’ve written a neat program in Perl or Tcl named $ The plus sign means “add a permission,” and the If you want to remove execute permission, use a minus sign in place of a plus: $ This command assigns permissions to all levels—user, group, and other. Let’s say that you are secretly into software hoarding and don’t want anybody to use the command but yourself. (No, that’s too cruel; let’s say instead that you think the script is buggy and want to protect other people from hurting themselves until you’ve exercised it.) You can assign execute permission just to yourself through the command: $ Whatever goes before the plus sign is the level of permission, and whatever goes after is the type of
permission. User permission (for yourself) is u, group permission is $ You can also assign multiple types of permissions: $ There are a few more shortcuts you can learn from the chmod manual page in order to impress someone looking over your shoulder, but they don’t offer any functionality besides what we’ve shown you. As arcane as the syntax of the mode argument may seem, there’s another syntax that is even more complicated. We have to describe it though, for several reasons. First of all, there are several situations that cannot be covered by the syntax, called symbolic mode, that we’ve just shown. Second, people often use the other syntax, called absolute mode, in their documentation. Third, there are times you may actually find the absolute mode more convenient. To understand absolute mode, you have to think in terms of bits and octal notation. Don’t worry, it’s not too hard. A typical mode contains three characters, corresponding to the three levels of permission (user, group, and other). These levels are illustrated in Figure 4-3. Within each level, there are three bits corresponding to read, write, and execute permission. Figure 4-3. Bits in absolute mode Let’s say you want to give yourself read permission and no permission to anybody else. You want to specify just the bit represented by the number 400. So the chmod command would be: $ To give read permission to everybody, choose the correct bit from each level: 400 for yourself, 40 for your group, and 4 for other. The full command is: $ This is like using a mode To give read and execute permission to everybody, you have to add up the read and execute bits. 400 plus 100 is 500, for instance. So the corresponding command is: $ which is the same as One final trick: how to set the default mode that is assigned to each file you create (with a text editor, the > redirection operator, and so on). You do so by
executing a umask command, or putting one in your shell’s start-up file. This file could be called The umask command takes an argument like the absolute mode in chmod, but the meaning of the bits is inverted. You have to determine the access you want to grant for user, group, and other, and subtract each digit from 7. That gives you a three-digit mask. For instance, say you want yourself to have all permissions (7), your group to have read and execute permissions (5), and others to have no permissions (0). Subtract each bit from 7 and you get 0 for yourself, 2 for your group, and 7 for other. So the command to put in your start-up file is: umask 027 A strange technique, but it works. The chmod command looks at the mask when it interprets your mode; for instance, if you assign execute mode to a file at creation time, it will assign execute permission for you and your group, but will exclude others because the mask doesn’t permit them to have any access. What is group command in Linux?The three commands used to manage group accounts on Red Hat Enterprise Linux (RHEL) and RHEL-like distributions fit this description nicely: Add a group: groupadd. Modify a group: groupmod. Delete a group: groupdel.
Which of the following commands can be used to change group ownership of a file directory?The chown command changes the owner of a file, and the chgrp command changes the group.
What command is used to move to another directory Linux?mv stands for move. mv is used to move one or more files or directories from one place to another in a file system like UNIX.
What is the command to list the files and folders in the directory in Linux?Use the ls command to display the contents of a directory. The ls command writes to standard output the contents of each specified Directory or the name of each specified File, along with any other information you ask for with the flags.
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