The JOURNAL procedure provides a record of an interactive session by saving, in a file, all text entered from the terminal in response to the IDL prompt. The first call to JOURNAL starts the logging process. The read-only system variable !JOURNAL is set to the file unit used. To stop saving commands and close the file, call JOURNAL with no parameters. If logging is in effect and JOURNAL is called with a parameter, the parameter is simply written to the journal file.
A string containing the name of the journal file to be opened or text to be written to an open journal file. If
is not supplied, and a journal file is not already open, the file
is used. Once journaling is enabled, a call to JOURNAL with
to be written into the journal file. Calling JOURNAL without
while journaling is in progress closes the journal file and ends the logging process.