Monitor

Log files

Tcl modules save all the important commands issued from the graphical user interface GUI to log files. Similarly, all operations (commands or programs) started from the shell can be recorded automatically. This is a standard facility on UNIX-like computers. For instance, our computers use batch which keeps the commands in the file /.bash history. A small program was written (monitor.tcl) to keep an eye on the automatic logging facility of the shell. This data is very
useful because often the set of options used

computer% monitor.tcl ˜/.bash_history >> commands_20110815.log &

Logging files is an extremely useful policy.

• They record the succession of operations necessary for the construction of the model.

• They greatly facilitate changes. From the original files and knowing the operations applied, it is possible to change one element in the pipeline of operations and re-generate the dependent information automatically.

• If something goes wrong, they insure that no information and little time is lost. This is particularly important because laptops are prone to power failure and because tools under development may crash. This precaution has already been very useful in the past.

• It is not an expensive policy. Log files are relatively small. In our experience, it is useful to regularly create new files, copying lines of commands from the log files and re-organising them in easy sequences of operations (possibly adding some comments) necessary to achieve a particular task.

A graphical Log window (log.tcl) module was also developed to receive and record text information. This module can also be used to buffer data.