NAME
tip,
cu —
serial
terminal emulator
SYNOPSIS
tip |
[-v]
-speed
system-name |
tip |
[-v]
-speed
phone-number |
cu |
[options]
phone-number |
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
tip:
-
-
- -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 tip.
-
-
- ~|
- 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 tip,
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.