Provided by: cu_1.07-20build1_amd64 bug


       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

       ~! 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 false.

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

            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


       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

       -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 cu.

            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)