If you are already logged into one machine, and/or you are on an
X-terminal and your desired host isn't among the menu of choices, there
is the option of using either the command telnet or the command
for a Remote Login, rlogin. All of the computers here at the
laboratory are connected together via a network, which allows fairly
free interchange between systems. For example, suppose our user
`karney
' was already logged into Suntsu and now wishes to log onto
HAX. He could type and see:
[lyman|3]
telnet haxTrying 192.55.106.13...
Connected to hax.
Escape character is '^]'.
Username:
karneyPassword:
VAX/VMS V5.5-2
**************************************************************
* Warning: Unauthorized access to this computer system is *
* prohibited. Violators are subject to criminal and civil *
* penalties. *
**************************************************************
Last interactive login on Friday, 9-JUL-1993 11:06
HAX$
If we had used the command rlogin, the result would have been the
same. The only difference between the two commands is that the first is
used mostly when dealing with large-scale networks, while rlogin
assumes more of a localized cluster of computers and takes advantage of
a (presumed to be existing) `~/.rhosts
' file on the target
computer. This file includes a computer name and username on that
computer (i.e. your username on HAX may be different from that on the UNIX
machines), allowing that user to log in and bypass the normal login
procedures. The nice thing about this system is that you only have to
give your password once (when you log onto your X terminal).
A file similar to the `/.rhosts
' file is the `.netrc
'
file, which holds ftp remote login data. See FTP, and man netrc for more information.
On the PPPL UNIX machines, a useful shorthand version of rlogin is to simply type the name of your intended host:
[lyman|4]
suntsu
Again, as in the case with xrsh, the absence of a command after
the host name implies a default command. Here the default is
rlogin, allowing you to log in to that computer. In addition,
this process requires that `/usr/hosts
' be in your PATH in
`~/.cshrc
'. After logging out (same process as with direct login),
the prompt returns to that of your original login computer.