readwriteexecute

Readwriteexecute, often abbreviated as rwx, is a description of a complete set of file permissions in many operating systems. It denotes the ability to read the contents of a file, write to it, and, for executable files or traversal of directories, execute or access it. In Unix-like systems, permissions are defined separately for three classes of users: the file owner (user), the file’s group, and all other users (others). Each class has three boolean bits corresponding to read, write, and execute, and a particular class may have any combination of these bits set. When a class has all three bits set, that class has full rwx permissions.

While rwx is a general descriptive term, it is commonly represented compactly as the permission string rwx for a single class, or as an octal value such as 7 (rwx), 6 (rw-), 5 (r-x), etc., with three digits representing user, group, and others. The command chmod 777 grants rwx to everyone; chmod 755 grants rwx for the owner and read/execute for others.

Special modes such as setuid, setgid, and the sticky bit modify how rwx is applied in practice and can affect security and behavior, especially on executables and shared directories. In Windows, permissions are handled through a different model (ACLs), but the conceptual idea of read, write, and execute rights exists in similar forms.

Usage and considerations: granting full rwx across all classes can expose a system to risk; administrators typically apply the principle of least privilege and may rely on access control lists or more granular permission schemes to limit who can read, modify, or execute a resource.

See also: chmod, file permissions, access control list, umask, setuid, setgid, sticky bit.