su
su is a Linux command in the Permissions category, rated intermediate difficulty. Switches to another user account (default: root). The syntax is su [options] [user]. Key options and parameters: user — target user (default: root). It returns new shell (if successful). A practical example: su - # Switch to root (login shell) su - username # Switch to user su -c "command" # Run command as another user A close relative is chmod, which changes file permissions (read, write, execute) for owner/group/others. A close relative is chown, which changes file owner and/or group ownership. A close relative is chgrp, which changes group ownership of files and directories. More about this category: Linux permission commands — chmod, chown, chgrp, umask, and more. Manage file permissions and ownership. Related Permissions commands: chmod, chown, chgrp, umask, sudo, getfacl, setfacl, chattr. This page is part of the free Linux Reference documentation covering 304+ commands, each with syntax, options, practical examples, and a difficulty rating.