IRIX Base Documentation 1998 November/IRIX 6.5.2 Base Documentation November 1998.img/usr/share/catman/u_man/cat1/cu.z/cu

Text File | 1998-10-20 | 16KB | 397 lines

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NNNNAAAAMMMMEEEE
     cu - call another UNIX system

SSSSYYYYNNNNOOOOPPPPSSSSIIIISSSS
     ccccuuuu [_o_p_t_i_o_n_s]  [----ssss speed]   ----llll line
     ccccuuuu [_o_p_t_i_o_n_s]  [----ssss speed]  [----llll line] [----nnnn] telno
     ccccuuuu [_o_p_t_i_o_n_s]  systemname

     where _o_p_t_i_o_n_s can be any of:
         [----hhhh]  [----dddd]  [----oooo | ----eeee]  [----cccc ccccllllaaaassssssss]

DDDDEEEESSSSCCCCRRRRIIIIPPPPTTTTIIIIOOOONNNN
     _c_u calls up another UNIX system, a terminal, or possibly a non-UNIX
     system.  It manages an interactive conversation with possible transfers
     of ASCII files.

     _c_u accepts the following options and arguments:

     ----ssss_s_p_e_e_d     Specifies the transmission speed (300, 1200, 2400, 4800,
                 9600); The default value is "Any" speed which will depend on
                 the order of the lines in the ////eeeettttcccc////uuuuuuuuccccpppp////DDDDeeeevvvviiiicccceeeessss file.

     ----llll_l_i_n_e      Specifies a device name to use as the communication line.
                 This can be used to override the search that would otherwise
                 take place for the first available line having the right
                 speed. When the ----llll option is used without the ----ssss option, the
                 speed of a line is taken from the Devices file. When the ----llll
                 and ----ssss options are both used together, cu will search the
                 Devices file to check if the requested speed for the
                 requested line is available. If so, the connection will be
                 made at the requested speed; otherwise an error message will
                 be printed and the call will not be made.  If the device is
                 not found in the Devices file, an error message similar to

                 _NNNN_OOOO _DDDD_EEEE_VVVV_IIII_CCCC_EEEE_SSSS _AAAA_VVVV_AAAA_IIII_LLLL_AAAA_BBBB_LLLL_EEEE

                 is printed.  The specified device is generally a directly
                 connected asynchronous line (e.g., ////ddddeeeevvvv////ttttttttyyyydddd4444) in which case
                 a telephone number (_t_e_l_n_o) is not required.  The specified
                 device need not be in the ////ddddeeeevvvv directory.  If the specified
                 device is associated with an auto dialer, a telephone number
                 must be provided.

                 A line also used by _g_e_t_t_y(1M) cannot be used with this
                 option.  A line in use by _u_u_g_e_t_t_y(1M) can be used, provided
                 the same physical device name is used by both cu and uugetty.
                 However, if _u_u_g_e_t_t_y(1M) is being used, there is likely to be
                 an autodialing modem on the line, using an entry in the
                 Dialers file like the HHHHaaaayyyyeeeessss22224444 entry, and ready to accept a
                 telephone, _t_e_l_n_o, number from the _c_u command.

                 Use of this option with _s_y_s_t_e_m_n_a_m_e rather than _t_e_l_n_o will not



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                 give the desired result (see _s_y_s_t_e_m_n_a_m_e below).

     ----hhhh          Emulates local echo, supporting calls to other computer
                 systems which expect terminals to be set to half-duplex mode.

     ----tttt          Used to dial an ASCII terminal which has been set to auto
                 answer.  Appropriate mapping of carriage-return to carriage-
                 return-line-feed pairs is set.

     ----dddd          Causes diagnostic traces to be printed.

     ----oooo          Designates that odd parity is to be generated for data sent
                 to the remote system.

     ----nnnn          For added security, will prompt the user to provide the
                 telephone number to be dialed rather than taking it from the
                 command line.

     ----eeee          Designates that even parity is to be generated for data sent
                 to the remote system.

     ----cccc_c_l_a_s_s     Specifies a modem "class" such as _A_C_U or _D_i_r_e_c_t found in the
                 Dialers file.

     _t_e_l_n_o       When using an automatic dialer, the argument is the telephone
                 number with equal signs for secondary dial tone or minus
                 signs placed appropriately for delays of 4 seconds.

     _s_y_s_t_e_m_n_a_m_e  A uucp system name may be used rather than a telephone
                 number; in this case, _c_u will obtain an appropriate direct
                 line or telephone number from ////eeeettttcccc////uuuuuuuuccccpppp////SSSSyyyysssstttteeeemmmmssss.... Note that
                 the _s_y_s_t_e_m_n_a_m_e option should not be used in conjunction with
                 the ----llll and ----ssss options as _c_u will connect to the first
                 available line for the system name specified, ignoring the
                 requested line and speed.  Note that only the telephone
                 number will be used from the ////eeeettttcccc////uuuuuuuuccccpppp////SSSSyyyysssstttteeeemmmmssss file; the
                 chatting to log into the remote system will not be used since
                 it is unlikely that an interactive user wants to start SLIP,
                 PPP, or UUCP.

     After making the connection, _c_u runs as two processes:  the _t_r_a_n_s_m_i_t
     process reads data from the standard input and, except for lines
     beginning with ~~~~, passes it to the remote system; the _r_e_c_e_i_v_e 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 is used to control input from the remote so the buffer is not
     overrun.  Lines beginning with ~~~~ have special meanings.

     The _t_r_a_n_s_m_i_t process interprets the following user initiated commands:






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     ~~~~....                  terminate the conversation.

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

     ~~~~!!!!_c_m_d...            run _c_m_d on the local system (via sssshhhh ----cccc).

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

     ~~~~^^^^ZZZZ                 suspend the _c_u session.  (^Z, control-Z, is the
                         current job control suspend character (see _c_s_h(1) and
                         _s_t_t_y(1)).

     ~~~~%%%%ccccdddd                change the directory on the local system.  Note:
                         ~~~~!!!!ccccdddd will cause the command to be run by a sub-shell,
                         probably not what was intended.

     ~~~~%%%%ttttaaaakkkkeeee _f_r_o_m [ _t_o ]  copy file _f_r_o_m (on the remote system) to file _t_o on
                         the local system.  If _t_o is omitted, the _f_r_o_m
                         argument is used in both places.  The shell commands
                         below are sent to the remote machine to cause it to
                         transmit the file.  In fact, they are sent in a
                         single line with semicolons (;) between each command.

                    stty -echo
                    if test -r arg1; then
                         (echo '~>':arg2;cat arg1;echo '~>')
                    else
                         echo cant\'t open: arg1
                    fi
                    stty echo


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

          For both ~~~~%%%%ttttaaaakkkkeeee and ppppuuuutttt commands, as each block of the file is
          transferred, consecutive single digits are printed to the terminal.

          The shell command line below is sent to the remote machine to cause
          it to accept the data.  Obviously, the shell on the remote machine
          must be /bin/sh or a shell that correctly interpret these commands.

                    stty -echo;(cat - > arg2)||cat - >/dev/null;stty echo


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






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     ~~~~%%%%bbbbrrrreeeeaaaakkkk
          transmit a BBBBRRRREEEEAAAAKKKK to the remote system (which can also be specified
          as ~~~~%%%%bbbb).

     ~~~~%%%%ddddeeeebbbbuuuugggg
          toggles the ----dddd debugging option on or off (which can also be
          specified as ~~~~%%%%dddd).

     ~~~~tttt   prints the values of the termio structure variables for the user's
          terminal (useful for debugging).

     ~~~~llll   prints the values of the termio structure variables for the remote
          communication line (useful for debugging).

     ~~~~%%%%nnnnoooossssttttoooopppp
          toggles between DC3/DC1 input control protocol and no input control.
          This is useful in case the remote system is one which does not
          respond properly to the DC3 and DC1 characters.

     The _r_e_c_e_i_v_e process normally copies data from the remote system to its
     standard output.  The program accomplishes the ~~~~%%%%ttttaaaakkkkeeee command by
     initiating an output diversion to a file when a line from the remote
     begins with ~~~~.

     Data from the remote is diverted (or appended, if >>>>>>>> is used) to _f_i_l_e on
     the local system.  The trailing ~~~~>>>> marks the end of the diversion.

     The use of ~~~~%%%%ppppuuuutttt requires _s_t_t_y(1) and _c_a_t(1) on the remote side.  It also
     requires that the current erase and kill characters on the remote system
     be identical to these current control characters on the local system.
     Backslashes are inserted at appropriate places.

     The use of ~~~~%%%%ttttaaaakkkkeeee requires the existence of _e_c_h_o(1) and _c_a_t(1) on the
     remote system.  Also, _t_a_b_s mode (See _s_t_t_y(_1)) should be set on the remote
     system if tabs are to be copied without expansion to spaces.

     When _c_u is used on system X to connect to system Y and subsequently used
     on system Y to connect to system Z, commands on system Y can be executed
     by using ~~. Executing a tilde command reminds the user of the local
     system uname.  For example, uname can be executed on Z, X, and Y as
     follows:

          uname
          Z
          ~[X]!uname
          X
          ~~[Y]!uname
          Y

     In general, ~~~~ causes the command to be executed on the original machine,
     ~~~~~~~~ causes the command to be executed on the next machine in the chain.




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EEEEXXXXAAAAMMMMPPPPLLLLEEEESSSS
     To dial a system whose telephone number is 9 201 555 1212 using 1200 baud
     (where dialtone is expected after the 9):
          cu  -s1200   9=12015551212

     If the speed is not specified, "Any" is the default value.

     To login to a system connected by a direct line:
          cu  -l  /dev/ttyXX

     or
          cu -l ttyXX

     To dial a system with the specific line and a specific speed:
          cu  -s1200  -l  ttyXX

     To dial a system using a specific line associated with an auto dialer:
          cu  -l  culXX  9=12015551212

     To use a system name:
          cu  systemname

FFFFIIIILLLLEEEESSSS
     /etc/uucp/Systems
     /etc/uucp/Devices
     /var/spool/locks/LCK..(tty-device)
     /dev/tty*

SSSSEEEEEEEE AAAALLLLSSSSOOOO
     cat(1), duart(7), echo(1), stty(1), uucp(1C), uugetty(1M), uname(1).

DDDDIIIIAAAAGGGGNNNNOOOOSSSSTTTTIIIICCCCSSSS
     Exit code is zero for normal exit, otherwise, one.

WWWWAAAARRRRNNNNIIIINNNNGGGGSSSS
     The _c_u command does not do any integrity checking on data it transfers.
     Data fields with special _c_u characters may not be transmitted properly.
     Depending on the interconnection hardware, it may be necessary to use a
     ~~~~.... to terminate the conversion even if ssssttttttttyyyy 0000 has been used.  Non-
     printing characters are not dependably transmitted using either the ~~~~%%%%ppppuuuutttt
     or ~~~~%%%%ttttaaaakkkkeeee commands.  _c_u between an IMBR1 and a penril modem will not
     return a login prompt immediately upon connection.  A carriage return
     will return the prompt.

     The device names, dialers, and so forth in /_e_t_c/_u_u_c_p/_D_e_v_i_c_e_s must be
     correct.  Because _c_u is suid-uucp, the device used, such as /_d_e_v/_t_t_y_m_3,
     must be readable and writable by the "user" uucp.

BBBBUUUUGGGGSSSS
     There is an artificial slowing of transmission by _c_u during the ~~~~%%%%ppppuuuutttt
     operation so that loss of data is unlikely.




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