login.1 - nroff source : Read login(I) in pdf, ps, or txt form.
login - sign onto UNIX
login [ username ]
The login command is used when a user initially signs onto UNIX, or it
may be used at any time to change from one user to another. The latter
case is the one summarized above and described here. See `How to Get
Started' for how to dial up initially.
If login is invoked without an argument, it asks for a user name, and,
if appropriate, a password. Echoing is turned off (if possible) during
the typing of the password, so it will not appear on the written record
of the session.
After a successful login, accounting files are updated and the user is
informed of the existence of .mail and message-of-the-day files. Login
initializes the user and group IDs and the working directory, then exe-
cutes a command interpreter (usually sh(I)) according to specifications
found in a password file.
Login is recognized by the Shell and executed directly (without fork-
/etc/passwd password file
init(VIII), getty(VIII), mail(I), passwd(I), passwd(V)
`Login incorrect.' if the name or the password is bad.
`No shell.', `No directory': consult a UNIX programming counselor.