talkd Daemon

Purpose

Provides the server function for the talk command.

Syntax

/usr/sbin/talkd [ -s ]

Description

Note: The talkd daemon is normally started by the inetd daemon. It can also be controlled from the command line, using SRC commands.

The /usr/sbin/talkd daemon is the server that notifies a user (the recipient) that another user (the caller) wants to initiate a conversation. The daemon sets up the conversation if the recipient accepts the invitation. The caller initiates the conversation by executing the talk command specifying the recipient. The recipient accepts the invitation by executing the talk command specifying the caller.

The talkd daemon listens at the socket defined in the /etc/services file. When the talkd daemon receives a LOOK_UP request from a local or remote talk process, the talkd daemon scans its internal invitation table for an entry that pairs the client process (the local or remote talk process) with a caller.

If no entry exists in the invitation table, the talkd daemon assumes that the client process is the caller. The talkd daemon then receives the client process' ANNOUNCE request. The talkd daemon broadcasts an invitation on the remote computer where the recipient first logged in (unless the caller specifies a particular tty device). This terminal usually is the console, but it may be another terminal.

Otherwise, the invitation is sent to the terminal that the second user first logged in to. This usually is the console, but it may be another terminal.

If an entry does exist in the talkd daemon's internal invitation table, the talkd daemon assumes that the client is the recipient. The talkd daemon returns the appropriate rendezvous address to the talk process for the recipient. The recipient process then establishes a stream connection with the caller process.

Note: The talkd daemon uses the Talk 4.3 protocol, which is not compatible with AIX® 4.2 versions of the talk process. The subserver name for the AIX 4.3 protocol is ntalk.

Changes to the talkd daemon can be made using the System Management Interface Tool (SMIT) or System Resource Controller (SRC), by editing the /etc/inetd.conf or /etc/services file. Entering talkd at the command line is not recommended. The talkd daemon is started by default when it is uncommented in the /etc/inetd.conf file.

The inetd daemon get its information from the /etc/inetd.conf file and the /etc/services file.

After changing the /etc/inetd.conf or /etc/services file, run the refresh -s inetd or kill -1 InetdPID command to inform the inetd daemon of the changes to its configuration file.

Debugging messages are sent to the syslogd daemon.

Note: The talkd daemon should be controlled using the System Management Interface Tool (SMIT) or by changing the /etc/inetd.conf file.

Manipulating the talkd Daemon with the System Resource Controller

The talkd daemon is a subserver of the inetd daemon, which is a subsystem of the System Resource Controller (SRC). The talkd daemon is a member of the tcpip SRC subsystem group. This daemon is enabled by default in the /etc/inetd.conf file and can be manipulated by the following SRC commands:

Item Description
startsrc Starts a subsystem, group of subsystems, or a subserver.
stopsrc Stops a subsystem, group of subsystems, or a subserver.
lssrc Gets the status or a subsystem, group or subsystems, or a subserver.

Flags

Item Description
-s Turns on socket-level debugging.

Examples

  1. To start the talkd daemon, enter the following:

    startsrc  -t ntalk

    This command starts the talkd subserver.
  2. To stop the talkd daemon normally, enter the following:

    stopsrc  -t ntalk

    This command allows all pending connections to start and existing connections to complete but prevents new connections from starting.
  3. To force stop the talkd daemon and all talkd connections, enter the following:

    stopsrc -f -t ntalk

    This command terminates all pending connections and existing connections immediately.
  4. To display a short status report about the talkd daemon, enter the following:

    lssrc -t ntalk

    This command returns the daemon's name, process ID, and state (active or inactive).

Files

Item Description
   
/etc/utmp Contains data about users currently logged in.