4.2. The text dump module

The goal of this module is to convert the binary data of the traces into a formatted text file.

The text dump module is a good example of a usage of the batch analysis module backend. In fact, the text dump module depends on it. You don't need to explicitly load the batchAnalysis module though, as lttv offers a rich module backend that deals with the dependencies, loading the module automatically if needed.

The text dump module is invoked just like the batchAnalysis module. It adds more options that can be specified in argument. You may specify the -o switch for the output file name of the text dump. You can enable the output of the field names (the identifier of the fields) with the -l switch. The -s switch, for process states, is very useful to indicate the state in which the process is when the event happens.

If you use the --help option on the textDump module, you will see all the detail about the switches that can be used to show per cpu statistics and per process statistics. You will notice that you can use both the switches for the batchAnalysis module and those for textDump. You will also notice that the options --process_state (from textDump) and --stats (from batchAnalysis) has the same short name "-s". If you choose to invoke this option using the short name, it will use the option of the last module loaded just before the -s switch.

For exemple, if you load the textDump module with -m textDump, it will first load the batchAnalysis module, and then load itself. As it is the last module loaded, the -s switch used after it will signify --process_stats. On the other hand, if you choose to specify explicitly the loading of both modules like this :

$ lttv -L path/to/lib/plugins -m batchAnalysis -s\
-m textDump -s -t trace

The first "-s" will invoke batchAnalysis --stats and the second "-s" will invoke textDump --process_state. The list of options generated by --help follows the order of registration of the options by the modules, therefore the invocation order of the modules.