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| Chapter 2 UNIX Commands |

## cu

    cu [options] [destination]

Call up another UNIX system or a terminal via a direct line or a modem. A non-UNIX system can also be called.

### Options

-b`n`

  Process lines using `n`-bit characters (7 or 8).

-c`name`

  Search UUCP's Devices file and select the local area network that matches `name` (this assumes connection to a system).

-d

  Print diagnostics.

-e

  Send even-parity data to remote system.

-h

  Emulate local echo and support calls to other systems expecting terminals to use half duplex mode.

-l`line`

  Communicate on `line` device (e.g., /dev/tty001).

-n

  Prompt user for a telephone number.

-o

  Use odd parity (opposite of -e).

-s`n`

  Set transmission rate to `n` (e.g., 1200, 2400, 9600 bps). Default is Any.

-t

  Dial an ASCII terminal that has auto answer set.

### Destination

`telno`

  The telephone number of the modem to connect to.

`system`

  Call the `system` known to uucp (run uuname to list valid system names).

`addr`

  An address specific to your local area network.

cu runs as two processes: transmit and receive. Transmit reads from standard input and passes lines to the remote system; receive reads data from the remote system and passes lines to standard output. Lines that begin with a tilde (`~`) are treated as commands and are not passed.

### Transmit options

~.

  Terminate the conversation.

~!

  Escape to an interactive shell on the local system.

~!`cmd`...

  Run command on local system (via sh -c).

~$`cmd`...

  Run command locally; send output to remote system.

~%cd

  Change directory on the local system.

~%take `file` [`target`]

  Copy `file` from remote system to `target` on the local system. If `target` is omitted, `file` is used in both places.

~%put `file` [`target`]

  Copy `file` from the local system to `target` on the remote system. If `target` is omitted, `file` is used in both places.

~ ~ ...

  Use two tildes when you want to pass a line that begins with a tilde. This lets you issue commands to more than one system in a cu chain. For example, use ~~. to terminate the conversation on a second system cu'd to from the first.

~%b

  Send a BREAK sequence to remote system.

~%d

  Turn debug mode on or off.

~t

  Print termio structure for local terminal.

~l

  Print termio structure for communication line.

~%ifc

  Turn on/off the DC3/DC1 XON/XOFF control protocol (characters ^S, ^Q) for the remainder of the session (formerly ~%nostop, which is still valid).

~%ofc

  Set output flow control either on or off.

~%divert

  Allow/prevent diversions not specified by ~%take.

~%old

  Allow/prevent old-style syntax for diversions received.

### Examples

Connect to terminal line /dev/ttya at 1200 baud:

>     cu -s1200 -l/dev/ttya

Connect to modem with phone number 555-9876:

>     cu 5559876

Connect to system named usenix:

>     cu usenix

Reference: ctrace |  | Reference: cut