File Permissions in Linux

As most operations in Linux are performed using files, knowing file permissions have significant importance in Linux OS. As a multi-user system, Linux needs to be extra careful regarding file access permissions for different users to prevent data breach. Every file can have one or more of the following 3 permissions defined.

• Read: This permission allows the user to read and list the file's content. They cannot modify the file.
• Write: This permission allows the user to modify the file's contents by adding, removing, or renaming the file. This permission limits the user to move or remove the file.
• Execute: This permission allows the user to execute programs. Without this permission you can either read or write to programs, but not execute them.

File type and access permissions for a specific file can also be checked by running ls -l on the bash terminal.