What are special file permissions in Linux

Special permissions in Linux are advanced permissions that can be set on files or directories and provide additional capabilities or restrictions.

What do special permissions do?

They allow you to manage privileges and system security more precisely than normal access rights (read, write, execute). Also, special access rights in Linux provide special capabilities or restrictions for a user, group, or files. These include the following access rights:

1. Execute right (execute): run executable files or use a command to perform certain actions.
2. Read: View the contents of a file or directory.
3. Write: Modify the contents of a file or create, modify, or delete files in a directory.

What are the special access rights

On a Linux system, there are various access rights to files and directories that determine what actions can be allowed or denied for a particular user or group of users. The following are the main special file access rights in Linux:

1. "setuid"(suid): when the"setuid" permission is set on an executable file, the process is started with the privileges of the owner of the file rather than the user who runs it. This provides a temporary privilege reset for certain tasks.
2. "setgid"(sgid): when the"setgid" permission is set on an executable file, the process is started with the privileges of the file owner's group, not the group of the user who starts it. This allows file and resource sharing between members of the same group.
3. "sticky bit": setting a"sticky bit" on a directory allows only the file owner to delete or move files within the directory, even if other users have write privileges to the directory. This is useful for general use of a directory such as /tmp to prevent other users from deleting or modifying files.

Typically, these special permissions are specified along with the standard permissions (rwx) and are denoted by symbolic or numeric values. For example, setuid is indicated by an"s" instead of an"x" for the owner of an executable file.

If you want to set or change special file permissions in Linux, you can use the chmod command with the appropriate arguments. For example, toset "setuid" on an executable file, you can use the command"chmod u+s filename".

How do I enable special access rights?

Special access rights (SUID, SGID and Sticky bit) can be set on files or directories using the chmod command in Linux.

To set SUID:

chmod +s file_name

To set SGID on a directory:

chmod +s directory_name

To install Sticky bit on a directory:

chmod +t derectory_name

Note: Installing SUIDs on files is recommended to be restricted as it can be a potential security threat to the system. Use special access rights with caution and only in situations where it is well justified and does not create vulnerabilities.

You can use the `ls-l` command to view the special access rights that have been set. The permissions, including special permissions, will be displayed as alphabetic or numeric values after the file or directory permissions.