NAME

tip, cu — serial terminal emulator

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 tip:

The following options are available for cu:

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:

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:

The variables ${REMOTE} and ${PHONES} are also exported.

FILES

DIAGNOSTICS

Diagnostics are, hopefully, self explanatory.

HISTORY

The tip command appeared in 4.2BSD.

BUGS

The full set of variables is undocumented and should, probably, be pared down.

0	<->	remote tty in
1	<->	remote tty out
2	<->	local tty out

Manual browser: tip(1)