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Accessing VTAIX

Introduction and Overview
Using Telnet to Access VTAIX
Logging On to VTAIX
- Selecting a Telnet Client
Logging Off VTAIX
Using the Keyboard
- Control (Ctrl) Key Sequences
Customizing Your Environment
Using the X Windows System

If you are using this guide with a UNIX system other than VTAIX, contact your system administrator for information regarding details of the logon procedure for your system. You may be able to use the following procedure and simply substitute the IP address or fully qualified hostname of your machine in place of "VTAIX.CC.VT.EDU". If you are using a stand-alone workstation, the computer may already display the logon prompt and all you need do is enter your userid and password; see Logging On to VTAIX for additional information about logging on.

To access VTAIX, you will need:

a terminal, personal computer running terminal emulation software, or workstation.
If you wish to run X applications, you must also be running an X server on your workstation (see Using the X Windows System for additional information).
access to the campus Ethernet . A modem and inbound modem pool userid are required by off-campus users in order to access the CBX. For more information, refer to the Virginia Tech Modem Pool (VTMP) page.

VTAIX supports a large variety of terminal types. A list of supported terminals is contained in the file /etc/termcap. Most workstations can emulate one of the predefined terminal types. The logon procedure on some systems will prompt you for the terminal type. You must specify the correct terminal type in order for the system editor to work correctly.

Using Telnet to Access VTAIX

If you have access to a computer that is connected to the campus Ethernet network or the Internet (e.g., using the Virginia Tech Internet software), you can access VTAIX using the telnet command by entering:

telnet VTAIX.CC.VT.EDU

The IP address of VTAIX is 198.82.161.244 which can be used instead of VTAIX.CC.VT.EDU with the telnet command. For more information on using telnet with the AIX operating system, see user's guide Introduction to Networking, Using AIX., (NK08).

After the connection is complete, the logon prompt will be displayed.

Note: If you only want to transfer files to or from VTAIX, you can use the ftp command instead of telnet to access your VTAIX account. See Example Usage - anonymous ftp.

Selecting a Telnet Client

For information on Telnet and SSH clients, refer to the Telnet & SSH page.

Micorsoft Windows Telnet Note: If you use to log on to VTAIX using only the cursor arrow, backspace, delete, and F1-F4 keys are defined for use with uni-XEDIT; Ctrl or Esc key sequences must be used to access other uni-Xedit functions.

EWAN Note: If you log on to VTAIX using EWAN, you will be able to use the arrow keys and key definitions bound to the keys of the numeric keypad. The Plus key in the numeric keypad performs the Erase to End-of-Line function with this telnet client. The F1, F2, F3, and F4 functions are bound to the Num Lock, /, *, and - keys of the Numeric keypad. The F1-F12 and the block of keys consisting of Insert, Home, PageUp, Delete, End, and Page Down do NOT function when EWAN is used.

Logging On to VTAIX

After access to VTAIX is achieved , the logon prompt will be displayed:
login:

Note:

UNIX is case sensitive. You must enter your userid in the correct case. Normally, userids are lower case and passwords are both upper and lower case.
Take your time entering the userid and password; on many systems, including VTAIX, you will not be able to use the backspace or delete key to correct a typing mistake. On VTAIX you can use the kill line (<Ctrl-U>) key sequence to delete the line which you have entered so that you can begin entering it again.

After you have entered your userid, the password prompt will appear:

Virginia Tech (vtaix.cc.vt.edu)
	Kerberos Initialization for "userid"
	Password:

where "userid" is the name of your userid. The password will not be displayed as you enter it.

If you enter an incorrect userid or password, the login prompt will reappear.

After your userid and password have been verified, the message of the day (motd) will be displayed:

*******************************************************************
	*                                                                 *
	*                                                                 *
	*                    sample message of the day                    *
	*                                                                 *
	*                                                                 *
	*******************************************************************

The shell prompt ("$" is the default prompt for the Bourne or Korn Shell, "%" is the default C shell prompt) will be displayed and you may enter UNIX commands.

Logging Out From VTAIX

To log out of the system enter "logout" or simply press Ctrl-D. You will then be returned to your prior working environment.

Note: Some userids are customized to prevent accidental logoff using the <Ctrl-D> key sequence. If <Ctrl-D> does not logoff your session, enter the command "logout".

If you have accessed the system via the vttelnet command, enter the command "quit" to drop your vttelnet connection. If you have accessed VTAIX via the CBX, you can drop the CBX connection by pressing the <Return> key (approximately ten times) until the "disconnected" message is displayed. If you were using a PC or MAC, you can now use command(s) or the escape sequencei(s) required by your terminal emulation software to return to the operating system prompt.

Note: If you are using a UNIX workstation to access VTAIX, do not turn the workstation off unless you are the system administrator for this machine and follow the appropriate "shutdown" procedure.

Using the Keyboard

The UNIX operating system is case sensitive!

Some keyboard characters have special meaning in the UNIX environment; see UNIX Special Characters for some of the most commonly used special characters.

The <Return> key is pressed to execute UNIX and user-written commands. Whenever <Return> appears in this section, press the key corresponding to this function. For example, to list the non-hidden files in the current directory:

ls   <Return>

The cat (conCATenate) command can be used to create or display the contents of files as well as to join files together. Use the following sequence of commands to create a file:

cat  >  my_first_file           <Return>
	Here is a line of text.         <Return>
	Here is a second line of text.  <Return>
	     .
	     .
	     .
	Ctrl-D.

To display the contents of the file just created, enter:

cat  my_first_file   <Return>

For the remainder of this guide, use of the <Return> key to execute UNIX and user-written commands will be assumed and not included as part of the command syntax in the example exercises.

Control (Ctrl) Key Sequences

Ctrl key sequences are executed immediately and need not be followed by an <Return> to take effect.

UNIX uses key sequences to execute commands such as deleting a character, terminating an executing command, and logging off. Some of the most important key sequences include (the first key sequence listed for each function is the default for VTAIX):

<Ctrl-H>

<backspace>

<Del>

Erase previous character: For example, suppose you made a mistake and typed "lx" instead of "ls" and discovered you mistake prior to pressing the <Return> key. To backspace over the last character, you could press the <Ctrl-H> key sequence, that is press the Ctrl (or Control key on some keyboards) and while it is depressed, press the h key:

     lx<Ctrl-H>s

<Ctrl-U>

<@>

Delete (kill) the current line: For example, if the full line was entered incorrectly, it can be deleted in its entirety by using the <Ctrl-U> key sequence:

     lx<Ctrl-U>

<Ctrl-C>

<Del>

Interrupt (intr) current command: This character is used to "interrupt" or "abort" many UNIX commands.

For example, suppose you had issued the man (display manual pages) command and decided to cancel it before it has finished executing:

     man   man
	     <Ctrl-C>

Do not use <Ctrl-Z> to interrupt a command you wish to terminate; this control sequence is used suspend the current active process, but does not kill nor cleanup temporary files created by the process (see Terminating a Process for additional information about use of this control sequence).

<Ctrl-D>

end-of-file

The end-of-file character has many uses. These include:

Terminating programs: You may exit many UNIX commands and programs with this character.
Terminating text entry: For example, to end the text of a note that you are typing in the mail program, enter <Ctrl-D>.
Logging out: Press <Ctrl-D> at the UNIX prompt to log out of the system in the traditional manner.

Where more than one "key" is listed for a command, different UNIX systems may use one or more keys to perform the indicated function. You need to be aware of the alternative keys for each function should you log onto another UNIX system which does not use the set with which you are familiar.

Customizing Your Environment

Many commands are available to allow you to customize or modify the UNIX environment to your liking. You may issue such commands after you are logged in to accomplish the changes you desire or place them in a customization file.

Changing System Default Key Definitions

The stty command can be used both to display the current key definitions and to change them.

To display the current values of keyboard command sequences, enter:

stty   -a

On some systems, the -a option is not recognized. On these systems, try using the "all" option:

stty   all

You can also use the stty command to change the key sequence designated to perform a selected command. For example, to assign "@" as the "kill line" character, enter:

stty   kill  @

You would now press the <@> key instead of <Ctrl-U> to delete the current line.

If <backspace> does not already function to delete the preceding character, you can enable it to do so by entering:

stty  erase  <backspace>

where <backspace> is the key to which you wish to assign the backspace function.

Note: On some systems, including VTAIX, you will receive an error message if you attempt to use the stty command to reassign a function to the key which currently performs a function.

Defining the Terminal Type

If you are using either the Bourne or Korn shells (a "$" appears as the default command prompt), you can use the following pair of commands to assign "vt100" to the TERM environmental variable:

TERM=vt100
	export TERM

Do not include spaces on either side of the equal sign. The variable name TERM is entered in all upper case.

If you are using the C shell (a "%" appears as the default command prompt), use the following command to assign "vt100" to the TERM environmental variable:

setenv TERM vt100

Userid Customization Files

You can also customize your environment by placing desired configuration commands in the file which is loaded by the command processor when you login.

If you are using either the Bourne or Korn Shell as your command processor ($ as the default prompt), you would add these commands to the file ".profile". The next time you log in, ".profile" will be executed automatically, and the changes you have made will take effect.

If you are using the C shell (% as the default prompt) include your customization commands in ".login" or ".cshrc" file. The ".login" file is invoked once when you log onto the system and typically contains stty, setenv, and umask commands. The ".cshrc" file is invoked each time a new C Shell process is started and typically contains history, set, and alias commands.

Using the X Windows System

In order to use X applications on a UNIX system, you need to be running an X Windows System server on your local machine and allow X clients to display back to it. Faculty and staff can obtain licenses for the eXceed X Windows Server for the MS Windows operating system from Information Technology Acquisitions. When the X client is initiated on VTAIX, the client output will appear in a window on your local display.

You can use the following series of steps to run an X application on VTAIX:

Logon to your work station in the usual fashion.
Initialize the X server on your local machine. On some machines, you will need do nothing as you are placed in an X window manager as soon as your logon. On RS/6000 workstations and some other machines, you can begin the X server by entering the command "xinit" or clicking the mouse button on the X Windows System icon. Again, the command required is dependent upon the implementation of the X Windows System which has been installed on your machine and you should see your system administrator for details.
Enable foreign X clients to display on your local machine.
On many machines this can be accomplished using the xhost command; however, this command is not available on all workstations. If you are using a DEC workstation, use the security option of the customize menu and insert the IP address (198.82.161.244 for VTAIX) of the host(s) who will be allowed to display on your workstation. If you are not using a DEC workstation and the xhost command is not available, contact your system administrator to determine the correct procedure to allow other machines to route their displays to your local machine.
For systems which support the xhost command, you can enter the following command to allow VTAIX clients to display on your local screen:
To enable additional hosts to display X clients on your screen, enter an xhost command for each of these machines. To enable display of all X clients targeted for your local machine, enter:
Logon to your userid on VTAIX
Set the display environment so that the output will be returned to your local machine:
If you are using the Bourne or Korn Shell and the IP address of the local display were "128.173.xxx.yyy", enter the following command to route the X client display back to your local display:
If you are using the C Shell and the IP address of the local display were "128.173.xxx.yyy", enter the following command to route the X client display back to your local display:
On many machines, you can substitute the fully qualified host name for the IP address in the DISPLAY command.
Run the desired application program.
For example, to run the SAS System as an X client, you would enter:
When you are finished with an X application, you can close the windows you do not need by invoking the appropriate windows command. Typically you can close a window by using the mouse to select the close box or select the close window option from the appropriate menu.

Accessing VTAIX Tasks

•	Request a VTAIX ID
•	Change your VTAIX password
•	Review VTAIX documentation

computing.vt.edu

Accessing VTAIX

Using Telnet to Access VTAIX