This article will deal with how to log on to the UNIX system, and how to log out.
Logging On
Initially, a user needs to get a userid and, optionally, a password. The userid is typed in at the login prompt, which usually looks like:
login:
Following the logon, the password prompt will appear:
password:
When the password is typed, it will not be echoed back to the display terminal for security reasons.
The first time a user logs on, a password may not be required. In this case, the user will be logged on automatically.
Changing Password
Upon logging onto UNIX for the first time, it is STRONGLY recommended that the user change his/her password, using the passwd command:
passwd
UNIX will ask for the old password, then the new one (twice), always with the echo turned off.
Some systems will provide restrictions on the password: IRIX will insist on a password of at least five characters and at least ones non-alphabetic character.
Also note that a maximum length of eight characters is used by the password algorithm: any password longer than eight characters will be truncated to eight.
Logging Out
Three commands can be used to log out of the UNIX session. These are: logout, exit, and CTL-D. Some systems may not accept the CTL-D or exit. They are roughly equivalent when logging out from the console.