Thanks, Rony; this is very timely. It has direct application to my use of ooRexx extensions to Eclipse.
-----Original Message----- From: Rony G. Flatscher [mailto:[email protected]] Sent: Thursday, July 10, 2014 09:10 To: Open Object Rexx Developer Mailing List Subject: [Oorexx-devel] Redirecting ooRexx' standard files at runtime... Just a nice feature of ooRexx which might not get really noticed, however at times may proof to be *quite* helpful, hence sharing it here. In ooRexx whenever one outputs to stdout, stderr or inputs from stdin, then the monitors .output, .error and .input are used. By default these monitors forward to .stdout, .stderr, and .stdin respectively. Having a monitor object allows one to exchange the destination object at runtime from within ooRexx, which might sound "exotic" at first. However, there are problems that can be solved extremely elegantly, knowing this infrastructure and behaviour of ooRexx. A case in question: currently, there is a student who has taken on the task to create a proof of concept of making ooRexx scripts available to programs, embedded in HTML texts in a platform independent manner (maybe a possible presentation for the 2015 International Rexx Symposium). The problem here is that any ooRexx output and input using standard files does not really yield visible outputs in the case of stdout and stderr, so testing and developing has been incredibly hard on the student. Once he told me about not seeing debug output from ooRexx scripts while invoking them via JavaScript and the Java-Plugin, however the Java debug output would be shown in the Java console, I suggested to change the ooRexx standard files at runtime from within ooRexx to redirect to Java's standard files (i.e. System.out, System.err, System.in) and gave him a quick hack. By redirecting ooRexx' .output, .error and .input to Java's standard streams the output of his ooRexx programs all of a sudden became visible in the Java console, easying debugging tremendeously for him. As I foresee a future need for this redirection to Java streams I added a routine BSF.redirectTo([Java|ooRexx]) and implemented ooRexx classes that subclass the ooRexx inputStream and outputStream classes, forwarding the ooRexx standard input and standard outputs from/to the appropriate Java standard streams (will be part of BSF.CLS in the next version of BSF4ooRexx). All the ooRexx-programs themselves remain unchanged, except for the very first one that needs to call BSF.redirectTo() once to carry out the redirection to the Java standard streams. So, if you ever deploy ooRexx scripts from environments where ooRexx input/output to/from standard files is not possible for whatever reason, just use this technique to redirect the ooRexx streams to the hosting environments ones. If you want to know what methods your replacement stream classes need to implement, just lookup the classes BSF.inputStream and BSF.printStream in BSF.CLS in the current beta of BSF4ooRexx. ---rony P.S.: In ooRexx 4.2 there got two new standard ooRexx streams added that are named .debugInput and .traceOutput. BSF.redirectTo() also takes care to redirect these streams in case they are defined in .local. ---------------------------------------------------------------------------- -- Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Oorexx-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/oorexx-devel ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Oorexx-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/oorexx-devel
