Which command is used to change file permissions in Linux?

The command used to change file permissions in Linux is "chmod." This command allows users to modify the read, write, and execute permissions for files and directories. With "chmod," you can set specific permissions for the owner of the file, the group, and others by using either symbolic notation (such as using letters to represent permissions) or octal notation (using numbers to define permissions).

For instance, using "chmod 755 filename" would grant the owner full permissions (read, write, execute), while the group and others would have read and execute permissions. This versatility makes "chmod" an essential tool for managing access control in a Unix-like operating system.

The other commands serve different purposes: "chown" is used to change the ownership of a file or directory, "touch" is used to create new, empty files or update the timestamp of existing files, and "cp" is used to copy files or directories. Understanding these distinctions is important for effective file management in Linux.