Chapter 4

Setting Up and Maintaining the ToolTalk Processes

Note - The ToolTalk database server program must be installed on all machines which store files that contain ToolTalk objects or files that are the subject of ToolTalk messages.

Location of the ToolTalk Service Files

The ToolTalk binaries and library are located in /usr/openwin with symbolic links located in /usr/dt. This ensures that users of either Common Desktop Environment (CDE) or OpenWindows™ (OW) get the same version of ToolTalk. Online man pages and ToolTalk demo program source are located in /usr/openwin.

Table 4-1 describes the ToolTalk Service files.

Table 4-1 ToolTalk Service Files

File/location	Description
`ttsession`	Communicates with other ttsessions on the network to deliver messages.
`rpc.ttdbserverd`	Stores and manages ToolTalk object specs and information on files referenced in ToolTalk messages.
`ttcp ttmv ttrm ttrmdir tttar`	These commands are standard operating system shell commands that inform the ToolTalk service when files that contain ToolTalk objects or files that are the subject of ToolTalk messages are copied, moved, or removed.
`ttdbck`	A database check and recovery tool for the ToolTalk databases.
`tt_type_comp`	This is a compiler for ptypes and otypes. It compiles the ptype and otype files and automatically installs them in the ToolTalk Types database.
`ttce2xdr`	Converts ToolTalk type data from the Classing Engine database format to the XDR-database format.
`ttsnoop`	This is a Motif application that enables you to register ToolTalk patterns and/or send ToolTalk messages, and to generally observe ToolTalk message traffic. It is useful both for debugging existing applications and as a tutor in understanding how different parts of a pattern filter incoming messages.
`tttrace`	`tttrace` is analogous to `truss`(1). It is an application that can be used in two ways. It enables you to trace either the message-passing and pattern-matching occurring in a given `ttsession`, or it can be used to provide a per-program trace of all calls into the ToolTalk API.
`libtt.so.2`	This is the application programming interface (API) library.
`tttk.h` and `tt_c.h` (located in `/usr/dt/include/Tt`)	Header files that contain the ToolTalk functions used by applications to send and receive messages.
`/usr/openwin/man/man1`	ToolTalk man pages for the user commands such as `ttsession`, `ttdbck`, `tt_type_comp`, and so on.
`/usr/openwin/man/man1m`	ToolTalk man pages for the ToolTalk administrative commands suc such as `rpc.ttdbserverd`, `ttdbck`, and so on.
`/usr/openwin/man/man3`	ToolTalk man pages for the ToolTalk API calls.
`/usr/openwin/man/man4`	ToolTalk man pages for the ToolTalk message sets, and for configuration files used for by `ttsession`(1) and `rpc.ttdbserverd`(1m)
`/usr/openwin/man/man5`	ToolTalk man pages for the ToolTalk include files.
`ttsample`, `edit_demo`, and `Makefile` (located in `/usr/openwin/share/src/tooltalk/demo`)	Source code for simple ToolTalk demo programs.

Version

All ToolTalk commands support a -v option that prints the version string.

Requirements

The software required by the ToolTalk service includes ONC RPC.

Environment Variables

This section addresss ToolTalk and related environment variables.

ToolTalk Environment Variables

There are several ToolTalk environment variables that may be set. Table 4-2 describes these variables.

Table 4-2 Environment Variables

Variable	Description
`TTSESSION_CMD`	Overrides the standard options specified when tools automatically start `ttsession`. If this variable is set, all ToolTalk clients use this command to automatically start their X sessions.
`TT_ARG_TRACE_WIDTH`	Defines the number of characters of argument and context values to print when in trace mode. The default is to print the first 40 characters.
`TT_FILE`	`ttsession` places a pathname in this variable when a tool is invoked by a message scoped to the defined file.
`TT_HOSTNAME_MAP`	Points to a map file. The defined map file is read into the ToolTalk client for redirecting host machines.
`TT_PARTITION_MAP`	Points to a map file. The defined map file is read into the ToolTalk client for redirecting file partitions.
`TT_SESSION`	`ttsession` communicates its session identifier to the tools that it starts. If this variable is set, the ToolTalk client library uses its value as the default session identifier. The string stored in this variable can be passed to `tt_default_session_set`.
`TT_TOKEN`	Notifies the ToolTalk client library that it has been started by `ttsession`; the client can then confirm to `ttsession` that the start was successful.
`TT_TRACE_SCRIPT`	Tells libtt to turn on client-side tracing as specified in the trace script for `tttrace`(1).
`TTPATH`	Tells the ToolTalk service where the ToolTalk Types databases used by `tt_type_comp`(1) and `rpc.ttdbserverd`(1M) reside.
`CEPATH`	Tells the Classing Engine where the ToolTalk Types databases reside.
`DISPLAY`	Causes `ttsession` to communicate its session identifier to the tools that it starts if the `TT_SESSION` variable is not set. If the DISPLAY variable is set, the ToolTalk client library uses its value as the default session identifier. This variable is typically set when `ttsession` is auto-started while running under OpenWindows. NOTE: Under the Solaris operating environment, this variable may not be passed across to some accounts. That is, if you are logged on the console as User A and switch-user to User B, `ttsession` may not autostart when you attempt to run a ToolTalk program that normally autostarts `ttsession`. To avoid this problem, either manually set the this variable or include it in your `.login` file.
`DTMOUNTPOINT`	If set, the value of this environment variable will be used in place of `/net` in pathnames constructed to answer `tt_host_netfile_file()`(3) queries, by `rpc.ttdbserverd`(1M).

A process is given a modified environment when it is automatically started by the ToolTalk service. The modified environment includes the environment variables $TT_SESSION, $TT_TOKEN, and any contexts in the start-message whose keyword begins with the dollar sign symbol ($). Optionally, the environment variable $TT_FILE may also be included in the modified environment if it is a file-scoped message.

Note - If the tt_open call will be invoked by a child process, the parent process must propagate the modified environment to that child process.

Other Environment Variables

The TMPDIR environment variable is another environment variable that you can set to manipulate the ToolTalk development environment. For example, the following line redirects files to the /var/tmp directory.

TMPDIR=/var/tmp

Environment Variables Required to Start Programs on Remote Hosts

The start string is always executed on the host on which ttsession is running; however, the executed process can start another process on another host.

To do this, first make your start string be similar to the following:

# rsh farhost myprog

Next, to make sure myprog is placed in the right session and receives its initial message, you need to propagate the important ToolTalk environment variables. The ttrsh shell script shown in Example 4-1 propagates these environment variables.

Example 4-1 Propagating ToolTalk Environment Variables

#! /bin/sh
# Runs a command remotely in background, by pointing stdout and stderr 
# at /dev/null. By running this through the Bourne shell at the other end, 
# we get rid of the rsh and rshd.
#set -x
user=
debug=
HOST=${HOST-`hostname`}
if [ "$1" = "-debug" ]; then
	debug=1
	shift
fi
if [ $# -lt 2 -o "$1" = "-h" -o "$1" = "-help" ]; 
then
	echo "Usage: ttrsh [-debug] remotehost [-l username] \
remotecommand"
	echo "Usage: ttrsh [-h | -help]"
	exit 1
else
	host=$1
	shift
	if test "$1" = "-l" ; then
		shift
		user=$1
		shift
	fi
fi
xhostname=`expr "$DISPLAY" : "\([^:]*\).*"`
xscreen=`expr "$DISPLAY" : "[^:]*\(.*\)"`
if test x$xscreen = x; then
	xscreen=":0.0"
fi
if test x$xhostname = x -o x$xhostname = x"unix";
then
	DISPLAY=$HOST$xscreen
fi
if [ "$user" = "" ]; then
	userOption=""
else
	userOption="-l $user"
fi
if [ $debug ]; then
	outputRedirect=
else
	outputRedirect='> /dev/null 2>&1 &'
fi
(
	echo "OPENWINHOME=$OPENWINHOME;export OPENWINHOME;\
TT_SESSION=$TT_SESSION;export TT_SESSION;\
TT_TOKEN=$TT_TOKEN;export TT_TOKEN;TT_FILE=$TT_FILE;\
export TT_FILE;DISPLAY=$DISPLAY;export DISPLAY;($*)" \
$outputRedirect | rsh $host $userOption /bin/sh &
) &