failiõigused

Failiõigused, known in English as file permissions, are a fundamental security mechanism in Unix-like operating systems, including Linux and macOS. They control which users can read, write, and execute files and directories. These permissions are typically assigned to three categories of users: the owner of the file, the group associated with the file, and all other users (often referred to as "others").

For each of these user categories, there are three basic permissions: read (r), write (w), and execute (x). The read permission allows a user to view the contents of a file or list the contents of a directory. The write permission allows a user to modify the contents of a file or create, delete, and rename files within a directory. The execute permission allows a user to run a file as a program or enter a directory.

These permissions are often represented numerically using an octal system. Read is represented by 4, write by 2, and execute by 1. These numbers are summed for each user category. For example, 777 would grant read, write, and execute permissions to the owner, group, and others, while 644 would grant read and write to the owner, and only read to the group and others.

The `chmod` command is used to change file permissions, and the `ls -l` command displays them in a human-readable format, showing a string like `-rwxr-xr--`. Understanding and managing file permissions is crucial for maintaining system security and ensuring that users have appropriate access to resources without compromising the integrity of the system.