NAME
tip,
cu
- connect to a remote system
SYNOPSIS
tip
[-v]
-speed
system-name
tip
[-v]
-speed
phone-number
cu
[options]
phone-number
cu
[options]
``dir''
cu
--help
DESCRIPTION
tip
and
cu
are used to connect to another system over a serial link.
In the era before modern networks, they were typically used to
connect to a modem in order to dial in to a remote host.
They are now frequently used for tasks such as attaching to the
serial console of another machine for administrative or
debugging purposes.
The following option is available for
:
- -v
-
Set verbose mode.
The following options are available for
cu:
- -a acu
-
Set the ACU port.
- -c number
-
Call this number.
- -E char
-
Use this escape character.
- -e
-
Use even parity.
- -F flow
-
Set flow control to
hard,
soft,
or
none.
- -f
-
Use no flow control.
- -h
-
Echo characters locally (half-duplex mode).
- -l line
-
Specify the line to use.
Either of the forms like
tty00
or
/dev/tty00
are permitted.
- -n
-
No escape (disable tilde).
- -o
-
Use odd parity.
- -P parity
-
Set parity to
even
or
odd.
- -p acu
-
Set the ACU port.
- -s speed
-
Set the speed of the connection.
Defaults to 9600.
- -t
-
Connect via a hard-wired connection to a host on a dial-up line.
For
cu,
if both
-e
and
-o
are given, then no parity is used.
This is the default behaviour.
If
speed
is specified it will override any baudrate specified in the system
description being used.
If neither
speed
nor
system-name
are specified,
system-name
will be set to the value of the
HOST
environment variable.
If
speed
is specified but
system-name
is not,
system-name
will be set to a value of
``tip''
with
speed
appended.
e.g.
tip -1200
will set
system-name
to
``tip1200''.
Typed characters are normally transmitted directly to the remote
machine (which does the echoing as well).
A tilde (`~') appearing
as the first character of a line is an escape signal; the following
are recognized:
- ~^D or ~
- .
Drop the connection and exit
(you may still be logged in on the
remote machine).
- ~c[ name]
-
Change directory to
name
(no argument
implies change to your home directory).
- ~!
-
Escape to a shell (exiting the shell will
return you to tip).
- ~>
-
Copy file from local to remote.
tip
prompts for the name of a local file to transmit.
- ~<
-
Copy file from remote to local.
tip
prompts first for the name of the file to be sent, then for
a command to be executed on the remote machine.
- ~p from[ to]
-
Send a file to a remote
UNIX
host.
The put command causes the remote
UNIX
system to run the command string ``cat > 'to''', while
tip
sends it the ``from''
file.
If the ``to'' file isn't specified the ``from'' file name is used.
This command is actually a
UNIX
specific version of the ``~>'' command.
- ~t from[ to]
-
Take a file from a remote
UNIX
host.
As in the put command the ``to'' file
defaults to the ``from'' file name if it isn't specified.
The remote host
executes the command string ``cat 'from';echo ^A'' to send the file to
.
- ~|
-
Pipe the output from a remote command to a local
UNIX
process.
The command string sent to the local
UNIX
system is processed by the shell.
- ~$
-
Pipe the output from a local
UNIX
process to the remote host.
The command string sent to the local
UNIX
system is processed by the shell.
- ~C
-
Fork a child process on the local system to perform special protocols
such as XMODEM.
The child program will be run with the following
arrangement of file descriptors:
0 <-> remote tty in
1 <-> remote tty out
2 <-> local tty out
- ~+
-
Synonym for ~C, provided for compatibility with other versions of
cu.
- ~#
-
Send a
BREAK
to the remote system.
For systems which don't support the
necessary
ioctl
call the break is simulated by a sequence of line speed changes
and
DEL
characters.
- ~s
-
Set a variable (see the discussion below).
- ~^Z
-
Stop
tip
(only available with job control).
- ~^Y
-
Stop only the ``local side'' of
tip
(only available with job control);
the ``remote side'' of
,
the side that displays output from the remote host, is left running.
- ~?
-
Get a summary of the tilde escapes
tip
uses the file
/etc/remote
to find how to reach a particular
system and to find out how it should operate while talking
to the system;
refer to
remote(5)
for a full description.
Each system has a default baud rate with which to
establish a connection.
If this value is not suitable, the baud rate
to be used may be specified on the command line, e.g.
`tip -300 mds'.
When
tip
establishes a connection it sends out a
connection message to the remote system; the default value, if any,
is defined in
/etc/remote
(see
remote(5)).
When
tip
prompts for an argument (e.g. during setup of
a file transfer) the line typed may be edited with the standard
erase and kill characters.
A null line in response to a prompt,
or an interrupt, will abort the dialogue and return you to the
remote machine.
tip
guards against multiple users connecting to a remote system
by opening modems and terminal lines with exclusive access,
and by honoring the locking protocol used by
uucico(8).
During file transfers
tip
provides a running count of the number of lines transferred.
When using the ~> and ~< commands, the ``eofread'' and ``eofwrite''
variables are used to recognize end-of-file when reading, and
specify end-of-file when writing (see below).
File transfers normally depend on tandem mode for flow control.
If the remote
system does not support tandem mode, ``echocheck'' may be set
to indicate
tip
should synchronize with the remote system on the echo of each
transmitted character.
When
tip
must dial a phone number to connect to a system it will print
various messages indicating its actions.
tip
supports the
DEC DN-11
and
Racal-Vadic 831 auto-call-units;
the
DEC DF02
and
DF03,
Ventel 212+, Racal-Vadic 3451, and
Bizcomp 1031 and 1032 integral call unit/modems.
VARIABLES
tip
maintains a set of
variables
which control its operation.
Some of these variables are read-only to normal users (root is allowed
to change anything of interest).
Variables may be displayed
and set through the ``s'' escape.
The syntax for variables is patterned
after
vi(1)
and
Mail(1).
Supplying ``all''
as an argument to the set command displays all variables readable by
the user.
Alternatively, the user may request display of a particular
variable by attaching a `?' to the end.
For example ``escape?'' displays
the current escape character.
Variables are numeric, string, character, or boolean values.
Boolean
variables are set merely by specifying their name; they may be reset
by prepending a `!' to the name.
Other variable types are set by
concatenating an `=' and the value.
The entire assignment must not
have any blanks in it.
A single set command may be used to interrogate
as well as set a number of variables.
Variables may be initialized at run time by placing set commands
(without the ``~s'' prefix in a file
.tiprc
in one's home directory).
The
-v
option causes
tip
to display the sets as they are made.
Certain common variables have abbreviations.
The following is a list of common variables,
their abbreviations, and their default values.
- beautify
-
(bool) Discard unprintable characters when a session is being scripted;
abbreviated
be.
- baudrate
-
(num) The baud rate at which the connection was established;
abbreviated
ba.
- dialtimeout
-
(num) When dialing a phone number, the time (in seconds)
to wait for a connection to be established; abbreviated
dial.
- echocheck
-
(bool) Synchronize with the remote host during file transfer by
waiting for the echo of the last character transmitted; default is
off.
- eofread
-
(str) The set of characters which signify an end-of-transmission
during a ~< file transfer command; abbreviated
eofr.
- eofwrite
-
(str) The string sent to indicate end-of-transmission during
a ~> file transfer command; abbreviated
eofw.
- eol
-
(str) The set of characters which indicate an end-of-line.
tip
will recognize escape characters only after an end-of-line.
- escape
-
(char) The command prefix (escape) character; abbreviated
es;
default value is `~'.
- exceptions
-
(str) The set of characters which should not be discarded
due to the beautification switch; abbreviated
ex;
default value is ``\t\n\f\b''.
- force
-
(char) The character used to force literal data transmission;
abbreviated
fo;
default value is `^P'.
- framesize
-
(num) The amount of data (in bytes) to buffer between file system
writes when receiving files; abbreviated
fr.
- host
-
(str) The name of the host to which you are connected; abbreviated
ho.
- prompt
-
(char) The character which indicates an end-of-line on the remote
host; abbreviated
pr;
default value is `\n'.
This value is used to synchronize during
data transfers.
The count of lines transferred during a file transfer
command is based on receipt of this character.
- raise
-
(bool) Upper case mapping mode; abbreviated
ra;
default value is
off.
When this mode is enabled, all lower case letters will be mapped to
upper case by
tip
for transmission to the remote machine.
- raisechar
-
(char) The input character used to toggle upper case mapping mode;
abbreviated
rc;
default value is `^A'.
- record
-
(str) The name of the file in which a session script is recorded;
abbreviated
rec;
default value is ``tip.record''.
- script
-
(bool) Session scripting mode; abbreviated
sc;
default is
off.
When
script
is
true
,
tip
will record everything transmitted by the remote machine in
the script record file specified in
record.
If the
beautify
switch is on, only printable
ASCII
characters will be included in
the script file (those characters between 040 and 0177).
The
variable
exceptions
is used to indicate characters which are an exception to the normal
beautification rules.
- tabexpand
-
(bool) Expand tabs to spaces during file transfers; abbreviated
tab;
default value is
false.
Each tab is expanded to 8 spaces.
- tandem
-
(bool) Use XON/XOFF flow control to throttle data from the remote host;
abbreviated
ta.
The default value is
true
unless the
nt
capability has been specified in
/etc/remote
,
in which case the default value is
false.
- verbose
-
(bool) Verbose mode; abbreviated
verb;
default is
true.
When verbose mode is enabled,
tip
prints messages while dialing, shows the current number
of lines transferred during a file transfer operations,
and more.
ENVIRONMENT
tip
uses the following environment variables:
SHELL
-
(str) The name of the shell to use for the ~! command; default
value is ``/bin/sh'', or taken from the environment.
HOME
-
(str) The home directory to use for the ~c command; default
value is taken from the environment.
HOST
-
Check for a default host if none specified.
The variables
${REMOTE}
and
${PHONES}
are also exported.
FILES
/etc/remote
-
Global system descriptions.
/etc/phones
-
Global phone number data base.
- ${REMOTE}
-
Private system descriptions.
- ${PHONES}
-
Private phone numbers.
- ~/.tiprc
-
Initialization file.
tip.record
-
Record file.
DIAGNOSTICS
Diagnostics are, hopefully, self explanatory.
SEE ALSO
phones(5),
remote(5)
HISTORY
The
tip
command appeared in
4.2BSD.
BUGS
The full set of variables is undocumented and should, probably, be
pared down.