Using two computers at the same time
The cu (call up) command makes your local
computer call a remote computer
and allows you to be logged in on both systems simultaneously.
The remote computer does not have to be a UNIX system.
If the remote computer is a UNIX system, cu allows you to
move back and forth between the two computers,
transferring files and executing commands on both.
Note that cu only allows you to transfer text files.
You cannot transfer binary files with cu.
To transfer binary files to a remote UNIX system, use
The format of the cu command is:
cu [options] target
The target argument can take one of four forms:
Once the connection is made, if the remote
computer is a UNIX system, you are presented with a login prompt.
Log in as you would if you were connected locally.
When you finish working on the remote computer,
log out as you would if you were connected locally,
then terminate the cu connection
by entering a tilde followed by a period (~.).
(The tilde, when entered at the beginning of a line, is an
escape character that tells cu to process the
next piece of text itself, instead of sending it to the remote
computer. The period is the cu command to terminate the
session. Other commands are available.)
This is the number of the remote computer to which you
want to connect.
You can embed equal signs, which represent secondary dial
tones, and dashes, which represent four-second delays, in
the telephone number.
A sample telephone number might be 4085551212--100.
This number contains an area code and number, two
dashes for an eight second delay, and an extension.
This is the name of a system that is listed in the
The cu command obtains the telephone number
and the baud rate of system-name from this file.
The -s, -n, and -l options should
not be used with system-name.
To see the list of computers in the Systems file,
This is the device name of the serial line connected to
the remote computer.
It has the form ttyXX, where
XX is the number of a serial line.
-l line dir
This connects directly with the serial line instead
of making a telephone connection.
As an example, suppose that you want to log in to a remote UNIX
computer via the telephone lines.
Suppose also that the remote computer's number is 555-1212.
To connect to the remote computer, enter the following command:
cu -s1200 5551212
The -s1200 option causes cu to use
a 1200 baud dialer.
If the -s option is not specified,
cu uses the first available dialer at the speed specified
in the /usr/lib/uucp/Devices file.
When the remote UNIX system answers the call,
cu notifies you that the connection has been made
by displaying the following message:
Next, you are prompted for your login:
Enter your login and password.
Once you enter this information, you can use this computer
as if you were logged in locally.
When you are finished, log out and then enter:
This terminates the cu session.
Transferring text files with take and put
Connecting to a remote terminal
© 2003 Caldera International, Inc. All rights reserved.
SCO OpenServer Release 5.0.7 -- 11 February 2003