tip, cu — connect to a remote system
cu [−ehot] [−a acu] [−l line] [−s speed] [−#] [phone-number]
The tip and cu utilities establish a full-duplex connection to another machine, giving the appearance of being logged in directly on the remote CPU. It goes without saying that you must have a login on the machine (or equivalent) to which you wish to connect. The preferred interface is tip. The cu interface is included for those people attached to the ’’call UNIX’’ command of Version 7 AT&T UNIX. This manual page describes only tip.
The options are as follows:
Set the acu.
For cu, specify the line to use. Either of the forms like tty00 or /dev/tty00 are permitted.
No escape (disable tilde).
For cu, set the speed of the connection. Defaults to 9600.
Set verbose mode.
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).
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. The tip utility prompts for the name of a local file to transmit.
Copy file from remote to local. The tip utility 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 is not 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 is not 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.
Fork a child process on the local system to perform special protocols such as XMODEM. The child program will be run with the following somewhat unusual arrangement of file descriptors:
local tty in
1 <-> local tty out
2 <-> local tty out
3 <-> remote tty in
4 <-> remote tty out
Send a BREAK to the remote system. For systems which do not support the necessary ioctl() call the break is simulated by a sequence of line speed changes and DEL characters.
Set a variable (see the discussion below).
List all variables and their values (if set).
Stop tip (only available with job control).
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.
To find the system description and thus the operating characteristics of system-name, tip searches for a system description with a name identical to system-name. The search order is as follows:
If the environment variable REMOTE does not start with a ’/’ it is assumed to be a system description, and is considered first.
If the environment variable REMOTE begins with a ’/’ it is assumed to be a path to a remote(5) database, and the specified database is searched.
The default remote(5) database, /etc/remote, is searched.
See remote(5) for full documentation on system descriptions.
The br capability is used in system descriptions to specify the baud rate with which to establish a connection. If the value specified is not suitable, the baud rate to be used may be given on the command line, e.g., ’’tip -300 mds’’.
When tip establishes a connection, it sends out the connection message specified in the cm capability of the system description being used.
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.
The tip utility 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 that 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. The tip utility supports a variety of auto-call units and modems with the at capability in system descriptions.
Support for Ventel 212+ (ventel), Hayes AT-style (hayes), USRobotics Courier (courier), Telebit T3000 (t3000) and Racal-Vadic 831 (vadic) units is enabled by default.
Support for Bizcomp 1031[fw] (biz31[fw]), Bizcomp 1022[fw] (biz22[fw]), DEC DF0-AC (df0), DEC DN-11 (dn11) and Racal-Vadic 3451 (v3451) units can be added by recompiling tip with the appropriate defines.
Note that if support for both the Racal-Vadic 831 and 3451 is enabled, they are referred to as the v831 and v3451, respectively. If only one of the two is supported, it is referred to as vadic.
The tip utility 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:
(bool) Discard unprintable characters when a session is being scripted; abbreviated be.
(num) The baud rate at which the connection was established; abbreviated ba.
(num) When dialing a phone number, the time (in seconds) to wait for a connection to be established; abbreviated dial.
(bool) Synchronize with the remote host during file transfer by waiting for the echo of the last character transmitted; default is off.
(str) The set of characters which signify an end-of-transmission during a ~< file transfer command; abbreviated eofr.
(str) The string sent to indicate end-of-transmission during a ~> file transfer command; abbreviated eofw.
(str) The set of characters which indicate an end-of-line. The tip utility will recognize escape characters only after an end-of-line.
(char) The command prefix (escape) character; abbreviated es; default value is ’~’.
(str) The set of characters which should not be discarded due to the beautification switch; abbreviated ex; default value is ’’\t\n\f\b’’.
(char) The character used to force literal data transmission; abbreviated fo; default value is ’^P’.
(num) The amount of data (in bytes) to buffer between file system writes when receiving files; abbreviated fr.
(str) The name of the host to which you are connected; abbreviated ho.
(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.
(bool) Upper case mapping mode; abbreviated ra; default value is off. When this mode is enabled, all lowercase letters will be mapped to uppercase by tip for transmission to the remote machine.
(char) The input character used to toggle uppercase mapping mode; abbreviated rc; default value is ’^A’.
(str) The name of the file in which a session script is recorded; abbreviated rec; default value is tip.record.
(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.
(bool) Expand tabs to spaces during file transfers; abbreviated tab; default value is false. Each tab is expanded to 8 spaces.
(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.
The name of the shell to use for the ~! command; default value is /bin/sh.
The home directory to use for the ~c command.
The default value for system-name if none is specified via the command line.
A system description, or an absolute path to a remote(5) system description database.
A path to a phones(5) database.
global remote(5) database
default phones(5) file
line access log
lock file to avoid conflicts with uucp(1)
The tip command appeared in 4.2BSD.
The full set of variables is undocumented and should, probably, be pared down.
BSD September 9, 2001 BSD