gtalkd - GNU talk daemon

gtalkd [ -bfghsStv --version ]

gtalkd is a talk daemon which is fully compatible with ntalkd which is the BSD talk daemon. gtalkd provides a talk service via the internet. A user may use a talk client to send a UDP message to gtalkd which will then provide the services of storing invitations, and making announcements to a user's terminal.

Command line switches are:

-b, --bsd

Emulate the BSD post 4.2 talk protocol by not accepting any GNU talk protocol extensions.

-f, --forever

Open a socket and loop on it forever. Unlike running under inetd during which stdin and stdout provides the socket necessary for communication, this option lets the talk daemon run as a separate self supporting process.

-g, --gnu

Run using the GNU talk protocol extensions. This is the default.

-h, --help

Print process help.

-s, --sun

Simulate the pre BSD 4.2 talk protocol which is commonly found on SunOS and Solaris.

-S, --sunforward

This option is run as an extended option for the --sun option. Instead of acting as a daemon and answering requests, all requests are sent to the n/gtalk daemon on the same machine. Answers are received and forwarded back the the requester.

-t, --tty

Send all error and verbose messages to the controlling TTY. In addition, create and bind the correct socket by hand instead of inheriting it through stdin and stdout.

-v, --verbose

Print out verbose information, or verbose syslog information.

--version

Print out the current version of gtalkd.

The GNU talk daemon can be placed in a system bin such as /usr/sbin or /usr/local/sbin and then installed in the inetd.conf file in place of the normal talk daemon which may be found there. The resulting configuration in inetd.conf should contain the following lines:

talk dgram udp wait root /usr/sbin/tcpd /sbin/gtalkd -Ss

ntalk dgram udp wait root /usr/sbin/tcpd /sbin/gtalkd

In addition, if you are installing on SunOS or Solaris, you will have to make it aware of the ntalk service. This service is found in /etc/services. Simply find the line which says:

talk 517/udp

and add the line

ntalk 518/udp

right after it.

/etc/inetd.conf

Contains definitions for the Internet Super Server to start gtalkd.

/etc/services

This file contains information relating names socket/service information to names. It is used to determine the "[n]talk" socket used when in forever mode.

/etc/passwd

Accessing /etc/passwd in the usual way allows gtalkd to determine a users home directory to read their personal ringer file. The ringer file allows gtalkd to forward announcements directly to an interested process.

~/.ringer

Different individuals may start applications which create and manage this file. The file contains a UDP socket definition which allows gtalkd to automatically pass the announcement information directly to a process which cares.

~/.talkfilter

This is read by gtalkd to determine of a pattern matches an incomming call for the callee. If it does, then the requested response is returned. A pattern is of the form

username@hostname DENY_METHOD

The username is a string which must match the incomming caller's id exactly. The hostname can be a substring of the caller's host name to match. One of username or hostname can be blank, which conflicts defaulting first to username only matches, and then to complete username,hostname combinations.

Valid DENY_METHODS are ALLOW , which allows a pattern to announce to you, and NOT_HERE , which cause gtalkd to predent you are not logged on. In addition, FAILED sends a failure message, and PERMISSION_DENIED pretends that you have permissions turned off on your tty. Lastly, SELECTIVE_REFUSAL means to send a specific message back saying that you have chosen to specifically prevent that person from calling you. If their client is not GTALK compliant, then it is downgraded to PERMISSION_DENIED

/etc/utmp, /var/adm/utmp

Different locations of utmp which contain login information for different users. This file is referenced to determine which TTY device to open in order to write an announcement message.

/dev/tty*

Terminal devices users are attached to. These devices are opened in order to write an announcement message.

Eric M Ludlam <zappo@gnu.org>

Report bugs to <zappo@gnu.org>. This system has never been tested in a high volume situation due to my limited resources.

Copyright © 1995, 1996 Eric M. Ludlam Copyright © 1997 Free Software Foundation.

The newest version of gtalkd can be found within the etalk distribution. As of the writing of this manual, it can be found on ftp.ultranet.com:/pub/zappo/gtalk-*.tar.gz

inetd(8),talk(1),etalk(1),xphone(1)