CU(1C)              UNIX Programmer's Manual               CU(1C)

NAME
     cu - call UNIX

SYNOPSIS
     cu telno [ -p ] [ -t ] [ -_n [ -s speed ] [ -a acu ] [ -l
     line ] [ -b ] [ -h ]

DESCRIPTION
     _C_u calls up another UNIX system, a terminal, or possibly a
     non-UNIX system.  It manages an interactive conversation
     with possible transfers of text files.  _T_e_l_n_o is the tele-
     phone number, with minus signs at appropriate places for
     delays.  If the -p option is specified, parity bits are
     stripped on both send and receive, otherwise the data path
     from the terminal to the remote system is a full 8 bits.
     The -t flag is used to dial out to a terminal.  _S_p_e_e_d gives
     the transmission speed (110, 134, 150, 300, 1200); 300 is
     the default value.

     The -a and -l values may be used to specify pathnames for
     the ACU and communications line devices.  They can be used
     to override the following built-in choices:

     -a /dev/cua0 -l /dev/cul0

     The -_n option, where _n is a single digit, changes the last
     character of the ACU and communications line to _n.  It is an
     abbreviation for -a /dev/cua_n -l /dev/cul_n.

     The -b flag specifies that nulls are to be turned into
     deletes (ascii \177).  This allows the break key (and also
     control-shift-@) to send an interrupt.

     Finally, the -h option causes local echo of all characters
     typed, for calling into a half-duplex system.

     After making the connection, _c_u runs as two processes: the
     _s_e_n_d process reads the standard input and passes most of it
     to the remote system; the _r_e_c_e_i_v_e process reads from the
     remote system and passes most data to the standard output.
     Lines beginning with `~' have special meanings.

     The _s_e_n_d process interprets the following:

     ~.                terminate the conversation.
     ~EOT              terminate the conversation

     ~<file            send the contents of _f_i_l_e to the remote
                       system, as though typed at the terminal.

     ~^Z               suspend the cu process.  Note that the
                       control-Z must be followed by a newline.

Printed 7/22/83                                                 1

CU(1C)              UNIX Programmer's Manual               CU(1C)

     ~#                sends a break.

     ~!                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 out-
                       put 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' name is used both
                       places.

     ~%put from [to]   copy file `from' (on local system) to file
                       `to' on remote system.  If `to' is omit-
                       ted, the `from' name is used both places.

     ~:                during an output diversion, this toggles
                       whether the operation of _c_u will be
                       silent, i.e., whether information received
                       from the foreign system will be written to
                       the standard output.  This allows a ``pro-
                       gress report'' during long transfers.

     ~~...             send the line `~...'.

     Both the _s_e_n_d and _r_e_c_e_i_v_e processes handles output diver-
     sions of the following form:

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

     In any case, output is diverted (or appended, if `>>' used)
     to the file.  If `:' is used, the diversion is _s_i_l_e_n_t, i.e.,
     it is written only to the file.  If `:' is omitted, output
     is written both to the file and to the standard output.  The
     trailing `~>' terminates the diversion.

     The use of ~%put requires _s_t_t_y and _c_a_t 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 _e_c_h_o and _t_e_e on
     the remote system.  Also, stty tabs mode is required on the
     remote system if tabs are to be copied without expansion.

Printed 7/22/83                                                 2

CU(1C)              UNIX Programmer's Manual               CU(1C)

FILES
     /dev/cua0
     /dev/cul0
     /dev/null
     /usr/spool/uucp/LCK..cu[al][0-7]

SEE ALSO
     dn(4), tty(4)

DIAGNOSTICS
     Exit code is zero for normal exit, nonzero (various values)
     otherwise.

BUGS
     Only _M_a_i_l(1) uses syntax anything like the syntax of _c_u.

Printed 7/22/83                                                 3