HPUX login[1]
login(1) login(1)
NAME
login - sign on
SYNOPSIS
login [name [env-var ...]]
DESCRIPTION
login is used at the beginning of each terminal session to properly
identify the prospective user. login can be invoked as a user
command, or by the system when an incoming connection is first
established. login is also invoked by the system when a previous user
shell terminates but the terminal does not disconnect.
If login is invoked as a command it must replace the initial command
interpreter (user's login shell). This is accomplished by typing:
exec login
from the user shell.
If name is not specified on the command line, login asks for login
name and, if required, the corresponding password. Terminal echo is
turned off (where possible) during typing of the password so that it
will not appear on any written record of the session. If the login
name provided is not valid, login requests a password. This is done
to make it more difficult for an unauthorized user to log in on the
system by trial and error. After three unsuccessful login attempts, a
HANGUP signal is issued.
As a security precaution, some installations use an option that
requires a second ``dialup'' password. This occurs only for dial-up
connections, and is prompted by the message dialup password:. Both
passwords must be correct for a successful login. See dialups(4) for
details on dialup security.
If password aging has been invoked by the user with appropriate
privileges on your behalf, your password may have expired. In this
case, you will be diverted into passwd to change it, after which you
can attempt to login again (see passwd(1)).
If login is not successfully completed within a certain period of time
(e.g., one minute), the terminal is silently disconnected.
After a successful login, the accounting files are updated, user and
group id's, group access list, and working directory are initialized,
and the user's command interpreter, usually one of the shells listed
in the sh(1) manual entry, is determined from corresponding user
entries in files /etc/passwd and /etc/logingroup (if /etc/passwd does
not specify a shell for user, /bin/sh is used by default). login then
forks the appropriate shell by using the last component of the shell
pathname preceded by a - (for example, -sh or -ksh). When the command
Hewlett-Packard Company - 1 - HP-UX Release 9.0: August 1992
login(1) login(1)
interpreter is invoked with its name preceded by a minus in this
manner, the shell performs its own initialization, including execution
of profile, login, or other initialization scripts.
For example, if the user login shell is sh(1) or ksh(1), the shell
executes the profile files /etc/profile and $HOME/.profile if they
exist (and possibly others as well, depending on what they contain).
Depending on what these profile files contain, messages regarding mail
in your mail file or any messages you may have received since your
last login may be displayed.
If the command name field is *, a chroot() to the directory named in
the directory field of the entry is performed. At that point login is
re-executed at the new level which must have its own root structure,
including /bin/login and /etc/passwd.
The basic environment (see environ(5)) is initialized to:
HOME=your_login_directory
PATH=:/bin:/usr/bin
SHELL=last_field_of_passwd_entry
MAIL=/usr/mail/your_login_name
TZ=timezone_specification
For users with appropriate privileges, PATH is augmented to include
/etc. In the case of a remote login, the enviroment variable TERM is
also set to the remote user's terminal type.
The environment can be expanded or modified by supplying additional
arguments to login, either at execution time or when login requests
your login name. The arguments can take either the form xxx or
xxx=yyy. Arguments without an equal sign are placed in the
environment as
Ln=xxx
where n is a number starting at 0 and is incremented each time a new
variable name is required. Variables containing an = are placed into
the environment without modification. If the name already appears in
the environment, the new value replaces the older one. There are two
exceptions. The variables PATH and SHELL cannot be changed. This
prevents users logged in with restricted shell environments from
spawning secondary shells that are not restricted. Both login and
getty understand simple single-character quoting conventions. Typing
a backslash in front of a character quotes it and allows the inclusion
of such things as spaces and tabs.
If /etc/btmp is present, all unsuccessful login attempts are logged to
this file. This feature is disabled if the file is not present. A
summary of bad login attempts can be viewed by users with appropriate
privileges by using lastb, see last(1M).
Hewlett-Packard Company - 2 - HP-UX Release 9.0: August 1992
login(1) login(1)
If /etc/securetty is present, login security is in effect, meaning
that only users with appropriate privileges are allowed to log in
successfully on the ttys listed in this file. Restricted ttys are
listed by device name, one per line. Valid tty names are dependent on
installation. Some examples could be console, tty01, ttya1, etc.
Note that this feature does not inhibit a normal user from using su.
DIAGNOSTICS
The following diagnostics appear if the associated condition occurs:
Login incorrect
User name or password cannot be matched.
No shell
Cannot open password file
No directory Consult system administrator.
Your password has expired. Choose a new one
Password aging is enabled and the user's password has
expired.
No Root Directory
Attempted to log into a subdirectory that does not
exist (i.e., passwd file entry had shell name *, but
the system cannot chroot to the given directory).
No /bin/login or /etc/login on root
Same as above except sub-root login command not found.
Bad user id or Bad group id.
setuid or setgid failed.
Unable to change to directory name
Cannot chdir to your home directory.
No shell User shell (or /bin/sh if shell name is null in
/etc/passwd) could not be exec'd.
Sorry, single-user
Occurs if the version field from uname(2) starts with A
(or if the uname system call fails) and if your
terminal name is not /dev/console and if your home
shell is not named /usr/lib/uucp/uucico. You are not
logged in.
No utmp entry. You must exec "login" from the lowest level "sh"
Attempted to execute login as a command without using
the shell's exec internal command or from other than
the initial shell.
Hewlett-Packard Company - 3 - HP-UX Release 9.0: August 1992
login(1) login(1)
.rhosts is a soft link
Personal equivalence file is a symbolic link.
Bad .rhosts ownership
Personal equivalence file is not owned by the local
user or by the the user with appropriate privileges.
Remuser too long
Locuser too long
Terminal type too long
Indicated string was too long for login's internal
buffer.
WARNINGS
If /etc/group is linked to /etc/logingroup, and group membership for
the user trying to log in is managed by the Network Information
Service (NIS), and no NIS server is able to respond, login waits until
a server does respond.
AUTHOR
login was developed by AT&T and HP.
FILES
$HOME/.profile personal profile (individual user
initialization)
$HOME/.rhosts personal equivalence file for the
remote login server
/etc/btmp history of bad login attempts
/etc/d_passwd dialup security encrypted passwords
/etc/dialups lines which require dialup security
/etc/hosts.equiv system list of equivalent hosts
allowing logins without passwords
/etc/logingroup group file - defines group access
lists
/etc/motd message-of-the-day
/etc/passwd password file - defines users,
passwords, and primary groups
/etc/profile system profile (initialization for
all users)
/etc/securetty list of valid ttys for root login
Hewlett-Packard Company - 4 - HP-UX Release 9.0: August 1992
login(1) login(1)
/etc/utmp users currently logged in
/etc/wtmp history of logins, logouts, and
date changes
/usr/mail/your_name mailbox for user your_name
VARIABLES
HOME user's home directory.
PATH path to be searched for commands.
SHELL which command interpreter is being used.
MAIL where to look for mail.
TERM user's terminal type.
TZ current timezone.
xxx User-specified named variables.
Lxxx User-specified unnamed variables.
SEE ALSO
mail(1), newgrp(1), passwd(1), sh(1), su(1), getty(1M), last(1M),
initgroups(3C), dialups(4), group(4), passwd(4), profile(4), utmp(4),
environ(5), privilege(5).
Hewlett-Packard Company - 5 - HP-UX Release 9.0: August 1992