4.2. Using the Readout GUI ReadoutShell

ReadoutShell provides a graphical user interface front end to the readout application. This front end supports:

• Starts the readout program on an arbitrary host.

• Starting, stopping, pausing, resuming runs

• Setting run parameters such as the title, run number and scaler readout period.

• Enabling or disabling software to start or stop recording event data to disk for later detailed analysis.

• Performing timed runs, that is runs that have a fixed pre-determined run time.

• User programmable actions to be performed when run state transitions are performed, or the Readout program started or restarted.

• Management of data sets and symbolic links so that event data can be treated as grouped with any arbitrary associated data files, or as just a directory containing the event data.

In this section we will create a script to start up the ReadoutShell in such a way that our readout program, ~/experiment/readout/Readout will be started by it. We will ensure our readout runs on the host specified by the DAQHOST environment variable, if it is defined, or localhost if not.

Consider the following script:

#!/bin/bash

. /etc/profile
. ~/.bashrc


if test "$DAQHOST" == ""
then
  host=`hostname`               # 
else
  host="$DAQHOST"
fi

/usr/opt/daq/8.1/bin/ReadoutShell -host=$host \
				  -path=$HOME/experiment/readout/Readout # 

                        

                

The readout application we wrote does not need to know what its working directory is, it also does not rely on any environment variables that got set by either the system wide, or user profile scripts (/etc/profile, and ~/.bashrc). It is possible that you might write a readout program that does rely on knowing the working directory, the value of an environment variable or both. In that case, instead of directly running the readout program, as shown in the example above, specify that the readout program is itself a shell script that will source the appropriate profiles and set the appropriate working directory.