How can you set or change file permissions in Linux?

In Linux, file permissions are set and modified using the chmod command.

Permissions are divided into three categories: owner (user), group (group), and others (others). For each category, you can set read (r), write (w), and execute (x) permissions.

Example usage:

• Setting read, write, and execute permissions for the owner, and only read permissions for the group and others:

chmod 744 filename

• Adding execute permission for all:

chmod +x filename

• Removing write permission for the group:

chmod g-w filename

You can also use symbolic or numeric modes to set permissions. To view current permissions, use the command ls -l filename.