| login | US |
| Begin session on the system. Called normally only by the system. | |
| logout | S |
| Terminates a login shell. Use exit instead, which terminates also other shells | |
| passwd [username] | UM |
| Change user password in the central user registry. Not identical to passwd described in the man page. Modified to cope with NIS and enhanced security. | |
| rlogin [-l user] host | U |
| Remote login to host (optionally as a different user). Use ssh instead. | |
| remsh [-l user] host [command] (HP-UX only) | U |
| rsh [-l user] host [command] (not HP-UX) | |
| Execute a command on a remote host (optionally as a different user). Acts like rlogin if no command is given. Use ssh instead. | |
| ssh [-l user] host [command] | P |
| Secure shell client. Remote login to host or execute a command on a remote host (optionally as a different user). Superior to rsh (X11 tunneling). | |
| su [-c command] [-s shell] [-] [user [arg[s]]] | U |
| Run a shell with substitute user and group IDs. The AFS permissions remain however the same and may have undesired side effects. Make the shell a login shell with option - | |
| telnet [options] [host [port]] | U |
| User interface to the TELNET protocol. For security reasons its use is discouraged. Better alternatives are ssh, and rsh (in this order of preference). |