rlogin(1tcp)

rlogin -- remote login

Synopsis

rlogin [-L] [-7] [-8] [-ec] [-l username] hostname

Description

The rlogin command establishes a remote login session from your terminal to the remote machine named hostname.

Options

rlogin takes the following options:

-L: Disable local tty character output processing (stty -opost) for the duration of the session.
-7: Strip local input characters to 7 bits (stty strip).
-8: Do not strip local input characters to 7 bits (stty -strip).
-e c: Specify a different escape character, c, for the line used to disconnect from the remote host. If c is the null string (""), no character is treated as the escape character.
-l username: Specify a different username for the remote login. If you do not use this option, the remote user name used is the same as your local user name.

Escape sequences

Lines that you type which start with the tilde character are ``escape sequences'' (the escape character can be changed using the -e options):

~.: Disconnect from the remote host. Note that this is not the same as a logout, because the local host breaks the connection with no warning to the remote end.
~!: Execute a local sub-shell.
~susp-char: Suspend the login session (only if you are using a shell with Job Control). susp-char is your ``suspend'' character, usually <ctrl><Z> (see tty(1)).

Files

/etc/passwd
/etc/hosts.equiv: list of trusted host names with shared user names
$HOME/.rhosts: private list of trusted host name/user name combinations
/usr/lib/locale/locale/LC_MESSAGES/uxrlogin: language-specific message file (See LANG on environ(5).)

Usage

Hostnames are listed in the hosts data base, which may be contained in the /etc/hosts file, in the Internet domain name server, or in both. Each host has one official name (the first name in the data base entry), and optionally one or more nicknames. Either official host names or nicknames may be specified in hostname.

If hostname is not specified, rlogin looks at the string by which it is invoked and uses it as the host name. This feature allows a user to create a link to /usr/bin/rlogin that can be named after a frequently accessed host. For example, the symbolic link $HOME/bin/marble pointing to /usr/bin/rlogin can be invoked as marble (if the user's PATH variable contains $HOME/bin).

Each remote machine may have a file named /etc/hosts.equiv containing a list of trusted host names with which it shares user names. Users with the same user name on both the local and remote machine may rlogin from the machines listed in the remote machine's /etc/hosts.equiv file without supplying a password. Individual users may set up a similar private equivalence list with the file .rhosts in their home directories. Each line in this file contains two names: a hostname and a username separated by a space. An entry in a remote user's .rhosts file permits the user named username who is logged into hostname to log in to the remote machine as the remote user without supplying a password. If the name of the local host is not found in the /etc/hosts.equiv file on the remote machine, and the local user name and host name are not found in the remote user's .rhosts file, then the remote machine will prompt for a password. Hostnames listed in /etc/hosts.equiv and .rhosts files must be the official host names listed in the hosts data base; nicknames may not be used in either of these files.

To counter security problems, the .rhosts file must be owned by either the remote user or by a privileged user.

The remote terminal type is the same as your local terminal type (as given in your environment TERM variable). The terminal or window size is also copied to the remote system if the server supports the option, and changes in size are reflected as well. All echoing takes place at the remote site, so that (except for delays) the remote login is transparent. Flow control using <ctrl><S> and <ctrl><Q> and flushing of input and output on interrupts are handled properly.

If the -L, -7, and -8 options are not used, your local opost and istrip stty settings are maintained.

Warnings

Note that, when a system is listed in hosts.equiv, its security must be as good as local security. One insecure system listed in hosts.equiv can compromise the security of the entire system.

When a line of the form hostname username appears in hosts.equiv, the user named may log in as anyone in the local password file by using the command

rlogin -l username hostname

where username is any valid user name in the passwd file.

This implementation can only use the TCP network service.

References

hosts(4tcp), hosts.equiv(4tcp), named(1Mtcp), rsh(1tcp), stty(1), tty(1)