CU(1) CU(1)
NAME
cu, ct - call out to a terminal or another system
SYNOPSIS
cu [ -htn ] [ -p parity ] [ -s speed ] telno [ service-class
]
ct [ option ... ] phone-number [ service-class ]
DESCRIPTION
Cu places a data call to a given telephone number and
expects a computer to answer. It manages an interactive
conversation with possible transfers of text files. Telno
is the telephone number, consisting of digits with minus
signs at appropriate places to indicate delay for second or
subsequent dial tones. A telephone number may also be
expressed symbolically. A symbolic number is looked up in
the files and whose lines look like this:
symbolic-number actual-number service-class comment
The actual number may be preceded by options such as -t.
The comment, if present, is printed out when the connection
is made.
The options are
-n Print the the called number but do not call it.
-t Tandem: use DC1/DC3 (control-S/control-Q) protocol to
stop transmission from the remote system when the local
terminal buffers are almost full. This argument should
only be used if the remote system understands that pro-
tocol.
-h Half-duplex: echo locally the characters that are sent
to the remote system.
-s speed
Set the line speed; `1200' means 1200 baud, etc. The
default depends on service class.
-p parity
Set the parity of transmitted characters: 0, 1, e, o
mean zero, one, even, odd parity. 0 is the default.
The service class is expressed as in dialout(3). A special
class `direct' causes the telno argument to be taken as the
pathname of a terminal line. Cu opens the file, sets line
speed and other modes, and proceeds as if connected. The
CU(1) CU(1)
default line speed is 9600 baud.
An explicit service class on the command line overrides any
specified in a `cunumber' file.
After making the connection, cu runs as two processes: the
sending process reads the standard input and passes most of
it to the remote system; the receiving process reads from
the remote system and passes most data to the standard out-
put. Lines beginning with `~' have special meanings.
The sending process interprets:
~.
~EOT Terminate the conversation.
~<file
Send the contents of file to the remote system, as
though typed at the terminal.
~! Invoke an interactive shell on the local system.
~!cmd
Run the command on the local system (via `sh -c').
~$cmd
Run the command locally and send its output to the
remote system.
~b
~%break
Send a break (300 ms space).
~%take from [to]
Copy file from (on the remote system) to file to on the
local system. If to is omitted, the from name is used
both places.
~%put from [to]
Copy file from (on local system) to file to on remote
system. If to is omitted, the from name is used both
places.
~~text
send the line ~text.
WARNING: Using cu to reach your home machine from a machine
you don't trust can be hazardous to your password.
Ct places a telephone call to a remote terminal and allows a
user to log in on that terminal in the normal fashion. The
terminal must be equipped with an auto-answer modem.
CU(1) CU(1)
The phone number and service class are as in cu. The options
are
-c count
If the number doesn't answer, try count times before
giving up (default 5).
-w interval
Space retries interval seconds apart (default 60).
-h Try to hang up the phone before placing the call. This
is useful for a `call me right back' arrangement.
FILES
SEE ALSO
con(1), ttyld(4), dialout(3)
BUGS
Unless erase and kill characters are the same on the two
machines, they will be damaged by ~%put.
~%take uses ~> at the beginning of line to synchronize
transmission. This sequence can cause misfunction if it is
received for any other purpose.