cu(1) cu(1)
NAME
cu - Call up another system
SYNOPSIS
ccuu [ options ] [ system | phone | "dir" ]
DESCRIPTION
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 sys-
tem to call. The -zz or --ssyysstteemm option may be used to name a system
beginning with a digit, and the -cc or --pphhoonnee 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 sys-
tem. The -pp,, --ppoorrtt,, -ll,, --lliinnee,, -ss and --ssppeeeedd options may be used to
control the port selection.
When a connection is made to the remote system, cu forks into two pro-
cesses. 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.
~~!! ccoommmmaanndd
Run command in a shell. If command is empty, starts up a shell.
~~$$ ccoommmmaanndd
Run command, sending the standard output to the remote system.
~~|| ccoommmmaanndd
Run command, taking the standard input from the remote system.
~~++ ccoommmmaanndd
Run command, taking the standard input from the remote system and
sending the standard output to the remote system.
~~##,, ~~%%bbrreeaakk
Send a break signal, if possible.
~~cc ddiirreeccttoorryy,, ~~%%ccdd ddiirreeccttoorryy
Change the local directory.
~~>> ffiillee
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
eeooffrreeaadd variable are seen.
~~pp ffrroomm ttoo,, ~~%%ppuutt ffrroomm ttoo
Send a file to a remote Unix system. This runs the appropriate
commands on the remote system.
~~tt ffrroomm ttoo,, ~~%%ttaakkee ffrroomm ttoo
Retrieve a file from a remote Unix system. This runs the appro-
priate commands on the remote system.
~~ss vvaarriiaabbllee vvaalluuee
Set a cu variable to the given value. If value is not given, the
variable is set to ttrruuee..
~~!! vvaarriiaabbllee
Set a cu variable to ffaallssee..
~~zz Suspend the cu session. This is only supported on some systems.
On systems for which ^Z may be used to suspend a job, ~~^^ZZ will
also suspend the session.
~~%%nnoossttoopp
Turn off XON/XOFF handling.
~~%%ssttoopp
Turn on XON/XOFF handling.
~~vv List all the variables and their values.
~~?? List all commands.
cu also supports several variables. They may be listed with the
~~vv command, and set with the ~~ss or ~~!! commands.
eessccaappee
The escape character. Initially ~~ (tilde).
ddeellaayy
If this variable is true, cu will delay for a second after recog-
nizing the escape character before printing the name of the local
system. The default is true.
eeooll 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.
bbiinnaarryy
Whether to transfer binary data when sending a file. If this is
false, then newlines in the file being sent are converted to car-
riage returns. The default is false.
bbiinnaarryy-pprreeffiixx
A string used before sending a binary character in a file trans-
fer, if the bbiinnaarryy variable is true. The default is ^V.
eecchhoo-cchheecckk
Whether to check file transfers by examining what the remote sys-
tem echoes back. This probably doesn't work very well. The
default is false.
eecchhoonnll
The character to look for after sending each line in a file. The
default is carriage return.
ttiimmeeoouutt
The timeout to use, in seconds, when looking for a character,
either when doing echo checking or when looking for the eecchhoonnll
character. The default is 30.
kkiillll The character to use delete a line if the echo check fails. The
default is ^U.
rreesseenndd
The number of times to resend a line if the echo check continues
to fail. The default is 10.
eeooffwwrriittee
The string to write after sending a file with the ~~>> command. The
default is ^D.
eeooffrreeaadd
The string to look for when receiving a file with the ~~<< command.
The default is $, which is intended to be a typical shell prompt.
vveerrbboossee
Whether to print accumulated information during a file transfer.
The default is true.
OOPPTTIIOONNSS
The following options may be given to cu.
-ee,, --ppaarriittyy==eevveenn
Use even parity.
-oo,, --ppaarriittyy==oodddd
Use odd parity.
--ppaarriittyy==nnoonnee
Use no parity. No parity is also used if both -ee and -oo are
given.
-hh,, --hhaallffdduupplleexx
Echo characters locally (half-duplex mode).
--nnoossttoopp
Turn off XON/XOFF handling (it is on by default).
-EE cchhaarr,, --eessccaappee cchhaarr
Set the escape character. Initially ~~ (tilde). To eliminate the
escape character, use -EE ''''..
-zz ssyysstteemm,, --ssyysstteemm ssyysstteemm
The system to call.
-cc pphhoonnee-nnuummbbeerr,, --pphhoonnee pphhoonnee-nnuummbbeerr
The phone number to call.
-pp ppoorrtt,, --ppoorrtt ppoorrtt
Name the port to use.
-aa ppoorrtt
Equivalent to --ppoorrtt ppoorrtt..
-ll lliinnee,, --lliinnee lliinnee
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.
-ss ssppeeeedd,, --ssppeeeedd ssppeeeedd
The speed (baud rate) to use.
-## Where # is a number, equivalent to --ssppeeeedd ##..
-nn,, --pprroommpptt
Prompt for the phone number to use.
-dd Enter debugging mode. Equivalent to --ddeebbuugg aallll..
-xx ttyyppee,, --ddeebbuugg ttyyppee
Turn on particular debugging types. The following types are rec-
ognized: abnormal, chat, handshake, uucp-proto, proto, port, con-
fig, 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 --ddeebbuugg
option may appear multiple times. A number may also be given,
which will turn on that many types from the foregoing list; for
example, --ddeebbuugg 22 is equivalent to --ddeebbuugg aabbnnoorrmmaall,,cchhaatt..
--ddeebbuugg aallll may be used to turn on all debugging options.
-II ffiillee,, --ccoonnffiigg ffiillee
Set configuration file to use. This option may not be available,
depending upon how cu was compiled.
-vv,, --vveerrssiioonn
Report version information and exit.
--hheellpp
Print a help message and exit.
BUGS
This program does not work very well.
AUTHOR Ian Lance Taylor
Taylor UUCP 1.07 cu(1)