cu(1)                        General Commands Manual                       cu(1)

       cu - Call up another system

       cu [ options ] [ system | phone | "dir" ]

       The cu command is used to call up another system and act as a dial in
       terminal.  It can also do simple file transfers with no error checking.

       cu takes a single argument, besides the options.  If the argument is the
       string "dir" cu will make a direct connection to the port.  This may only
       be used by users with write access to the port, as it permits
       reprogramming the modem.

       Otherwise, if the argument begins with a digit, it is taken to be a phone
       number to call.  Otherwise, it is taken to be the name of a system to
       call.  The -z or --system option may be used to name a system beginning
       with a digit, and the -c or --phone option may be used to name a phone
       number that does not begin with a digit.

       cu locates a port to use in the UUCP configuration files.  If a simple
       system name is given, it will select a port appropriate for that system.
       The -p, --port, -l, --line, -s and --speed options may be used to control
       the port selection.

       When a connection is made to the remote system, cu forks into two
       processes.  One reads from the port and writes to the terminal, while the
       other reads from the terminal and writes to the port.

       cu provides several commands that may be used during the conversation.
       The commands all begin with an escape character, initially ~ (tilde).
       The escape character is only recognized at the beginning of a line.  To
       send an escape character to the remote system at the start of a line, it
       must be entered twice.  All commands are either a single character or a
       word beginning with % (percent sign).

       cu recognizes the following commands:

       ~.   Terminate the conversation.

       ~! command
            Run command in a shell.  If command is empty, starts up a shell.

       ~$ command
            Run command, sending the standard output to the remote system.

       ~| command
            Run command, taking the standard input from the remote system.

       ~+ command
            Run command, taking the standard input from the remote system and
            sending the standard output to the remote system.

       ~#, ~%break
            Send a break signal, if possible.

       ~c directory, ~%cd directory
            Change the local directory.

       ~> file
            Send a file to the remote system.  This just dumps the file over the
            communication line.  It is assumed that the remote system is
            expecting it.

       ~<   Receive a file from the remote system.  This prompts for the local
            file name and for the remote command to execute to begin the file
            transfer.  It continues accepting data until the contents of the
            eofread variable are seen.

       ~p from to, ~%put from to
            Send a file to a remote Unix system.  This runs the appropriate
            commands on the remote system.

       ~t from to, ~%take from to
            Retrieve a file from a remote Unix system.  This runs the
            appropriate commands on the remote system.

       ~s variable value
            Set a cu variable to the given value.  If value is not given, the
            variable is set to true.

       ~! variable
            Set a cu variable to false.

       ~z   Suspend the cu session.  This is only supported on some systems.  On
            systems for which ^Z may be used to suspend a job, ~^Z will also
            suspend the session.

            Turn off XON/XOFF handling.

            Turn on XON/XOFF handling.

       ~v   List all the variables and their values.

       ~?   List all commands.

            cu also supports several variables.  They may be listed with the ~v
            command, and set with the ~s or ~!  commands.

            The escape character.  Initially ~ (tilde).

            If this variable is true, cu will delay for a second after
            recognizing the escape character before printing the name of the
            local system.  The default is true.

       eol  The list of characters which are considered to finish a line.  The
            escape character is only recognized after one of these is seen.  The
            default is carriage return, ^U, ^C, ^O, ^D, ^S, ^Q, ^R.

            Whether to transfer binary data when sending a file.  If this is
            false, then newlines in the file being sent are converted to
            carriage returns.  The default is false.

            A string used before sending a binary character in a file transfer,
            if the binary variable is true.  The default is ^V.

            Whether to check file transfers by examining what the remote system
            echoes back.  This probably doesn't work very well.  The default is

            The character to look for after sending each line in a file.  The
            default is carriage return.

            The timeout to use, in seconds, when looking for a character, either
            when doing echo checking or when looking for the echonl character.
            The default is 30.

       kill The character to use delete a line if the echo check fails.  The
            default is ^U.

            The number of times to resend a line if the echo check continues to
            fail.  The default is 10.

            The string to write after sending a file with the ~> command.  The
            default is ^D.

            The string to look for when receiving a file with the ~< command.
            The default is $, which is intended to be a typical shell prompt.

            Whether to print accumulated information during a file transfer.
            The default is true.

       The following options may be given to cu.

       -e, --parity=even
            Use even parity.

       -o, --parity=odd
            Use odd parity.

            Use no parity.  No parity is also used if both -e and -o are given.

       -h, --halfduplex
            Echo characters locally (half-duplex mode).

            Turn off XON/XOFF handling (it is on by default).

       -E char, --escape char
            Set the escape character.  Initially ~ (tilde).  To eliminate the
            escape character, use -E ''.

       -z system, --system system
            The system to call.

       -c phone-number, --phone phone-number
            The phone number to call.

       -p port, --port port
            Name the port to use.

       -a port
            Equivalent to --port port.

       -l line, --line line
            Name the line to use by giving a device name.  This may be used to
            dial out on ports that are not listed in the UUCP configuration
            files.  Write access to the device is required.

       -s speed, --speed speed
            The speed (baud rate) to use.

       -#   Where # is a number, equivalent to --speed #.

       -n, --prompt
            Prompt for the phone number to use.

       -d   Enter debugging mode.  Equivalent to --debug all.

       -x type, --debug type
            Turn on particular debugging types.  The following types are
            recognized: abnormal, chat, handshake, uucp-proto, proto, port,
            config, spooldir, execute, incoming, outgoing.  Only abnormal, chat,
            handshake, port, config, incoming and outgoing are meaningful for

            Multiple types may be given, separated by commas, and the --debug
            option may appear multiple times.  A number may also be given, which
            will turn on that many types from the foregoing list; for example,
            --debug 2 is equivalent to --debug abnormal,chat.  --debug all may
            be used to turn on all debugging options.

       -I file, --config file
            Set configuration file to use.  This option may not be available,
            depending upon how cu was compiled.

       -v, --version
            Report version information and exit.

            Print a help message and exit.

       This program does not work very well.

       Ian Lance Taylor <>

                                Taylor UUCP 1.07                           cu(1)