Using talk to communicate with other users

Purdue Engineering Computer Network

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The UNIX talk program is probably the most common application used for direct communication with others. To use talk, two people must agree to communicate with each other. The process starts when one person calls the other, using talk to set up the communications link.

1. The command syntax, from your unix prompt, is:

   	talk username@hostname
   

   where "username" is your friend's username, and "hostname" is the Internet address of the machine he is on. For example:

   	% talk my_friend@ranger.ecn.purdue.edu
   

2. What happens next?

   If "my_friend" is logged in, a message like this will appear on his/her screen:

   	Message from Talk_Daemon@ranger.ecn.purdue.edu at 13:15 ...
   	talk: connection requested by cathyc@america.ecn.purdue.edu
   	talk: respond with: talk cathyc@america.ecn.purdue.edu
   

   If my friend does not notice, the terminal's "bell" will beep a few times. If my friend wants to talk back, he/she must issue the command talk cathyc@america.ecn.purdue.edu. When she does this, a connection is made and the screen clears. The screen is then divided vertically into two halves. Anything I type to "my friend" is displayed on the top half of my screen and the bottom half of "my friend's" screen, and vice versa.

   Your friend will see what you type as you type it, and you'll see what your friend types too.

   If *either* party exits "talk" (with a control-c) then you will go right back to your unix prompt.

3. What If I Don't Want To Talk?

   Typing the command:

   	%  mesg n
   

   disables incoming talk conversations. You can still call other people, and they can connect to a call you make. The only thing that is affected is your ability to receive talk messages initiated by someone else. This remains in effect until you log off or give the command:

   	% mesg y
   

   If you are not participating, the requesting person will get the message:

   	[Your party is refusing messages] or
   	[You don't exist. Go away.]
   

4. What If It Didn't Work Right?

   The talk command depends upon a number of things to work successfully.

   • both computers must use the same underlying protocol (i.e., speak the same language) for talk
   • both computers must know about each other's existence and there must be an Internet network connection between the two computers
   • both people trying to talk must be logged in.
   • Another problem may be the OLD talk and the NEW talk protocols. There are two versions of the talk protocol -- the original, which is the standard that is shipped with Solaris, has problems when talking with machines that use a different internal data representation. The newer version, called ntalk fixes these problems. Within the Purdue University environment, ntalk (as it is sometimes called) is set as the default talk program and is installed in /usr/local/bin/talk. However, because other off-campus sites may not use this newer version (it is not shipped by Sun), we have left the Sun standard (old) version of talk in /usr/bin/talk. Thus, if you simply type talk, you will get the new version; if you have trouble talking to a friend at an off-campus site, you might try using /usr/bin/talk instead.

Y-Talk and IRC

Y-Talk and IRC are not installed in the ECN environment because the installation of these programs would not be in the best interest and in accordance with the missions of the Schools of Engineering.