


      CU(1)                       (UNIX 5.0)                      CU(1)



      NAME
           cu - call another system

      SYNTAX
           cu [-s speed] [-l line] [-h] [-t] [-d] [-m] [-o |-e]

      DESCRIPTION
           Cu calls a UNIX System, a terminal, or a non-UNIX system. It
           manages an interactive conversation with possible transfers
           of ASCII files.  Speed gives the transmission speed (110,
           150, 300, 600, 1200, 2400, 4800, 9600, 19200).

           -l specifies a device name for the communications line
           device to be used.

           -h emulates local echo, allowing calls to other computer
           systems which expect terminals to be in half-duplex mode.
           The -t option is used when dialing an ASCII terminal which
           has been set to auto-answer.  Appropriate mapping of
           carriage-returns to carriage-return-line-feed pairs is set.
           The -m option specifies a direct line which has modem
           control.  The -e (-o) option designates that even (odd)
           parity is to be generated for data sent to the remote.

           After making the connection, cu runs as two processes. The
           transmit process reads data from the standard input and,
           except for lines beginning with ~, passes it to the remote
           system.  The receive process accepts data from the remote
           system and, except for lines beginning with ~, passes it to
           the standard output.  Normally, an automatic DC3/DC1
           protocol controls input from the remote so the buffer is not
           overrun.  Lines beginning with ~ have special meanings.

           The transmit process interprets the following:

           ~.                  terminate the conversation.

           ~!                  escape to an interactive shell on the
                               local system.

           ~!cmd...            run cmd on the local system (via sh -c).

           ~$cmd...            run cmd locally and send its output to
                               the remote system.

           ~% take from [ to ] copy file from (on the remote system) to
                               file to on the local system.  If to is
                               omitted, the from argument is used in
                               both places.

           ~% put from [ to ]  copy file from (on local system) to file
                               to on remote system.  If to is omitted,



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                               the from argument is used in both
                               places.

           ~~...               send the line ~...  to the remote
                               system.

           ~% nostop           turn off the DC3/DC1 input control
                               protocol for the remainder of the
                               session.  Use this if the remote system
                               is one which does not respond to the DC3
                               and DC1 protocol.

           ~% b                or

           ~% break            transmit a BREAK to the remote system.

           ~^Z                 suspend (only when using csh).

           The receive process normally copies data from the remote
           system to its standard output.  A line from the remote that
           begins with ~> initiates an output diversion to a file.  The
           complete sequence is:

                ~>[>]:file
                zero or more lines to be written to file
                ~>

           Data from the remote is diverted (or appended, if >> is
           used) to file.  The trailing ~> terminates the diversion.

           The use of ~% put requires stty(1) and cat(1) on the remote
           side.  It also requires that the current erase and kill
           characters on the remote system be identical to the current
           ones on the local system.  Backslashes are inserted at
           appropriate places.

           The use of ~% take requires the existence of echo(1) and
           cat(1) on the remote system.  Also, stty tabs mode should be
           set on the remote system if tabs are to be copied without
           expansion.

      FILES
           /dev/null
           /dev/tty?

      SEE ALSO
           cat(1), echo(1), stty(1), uucp(1).

      DIAGNOSTICS
           Reguest device not available
                       UUCP has created a lock file (LCK..tty*) in the
                       /usr/spool/uucp directory.  If no one is using



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      CU(1)                       (UNIX 5.0)                      CU(1)



                       the specified port, remove the lock file.

           Exit code is zero for normal exit, non-zero (various values)
           otherwise.

      BUGS
           Cu buffers input internally.
           There is an artificial slowing of transmission by cu during
           the ~% put operation so that loss of data is unlikely.














































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