Has any one used XML tech in QNX ?, and for what. What is the tradeoff of implementing an semantic language like XML in an RTOS (compared to Windows).

Of course, much of Momentics uses XML (yes Momentics runs on QNX :slight_smile:.

What do you mean ?

XML is a markup language. It’s simply a standard for annotating data with metadata (in an extensible format), I fail to see how the category of OS implies that any tradeoffs need to be made.

Hi , j

Would it efficient to design a compact (not a real database) database using XML or go ahead with binary files and embedded the data in C header files. I guess there is some overhead involved with XML when it comes to dealing small applications.



XML is an excellent choice for a small single user database (very common in embedded systems). The code penalty for using XML is miniscule compared to anything else you may conceive of for storing/retrieving data. The file format is not very efficient, but that is a given. It does compress well though…

The problem: Designing a small database which stores some variables for the operation of hard real time system.
The approach:
Store the data as binary files, and wrap an API around the database.
Use XML with third party API to make life simple .


Has anyone used expat as an API for XML, also please comment on using third party API’s (ex: libxml, expat) for hard real time systems.

We use expat (an older version). Works quite well for us. We XML for our config files.

I too use expat under 621 and soon 630.
Its simple to use and makes config files easy to manage.
There is loads of stuff on the web for reference as well as plenty of sample code.
Here a are some links I used in tha past:

Hope this helps.


I have decided to use libxml, i would like to know if , for example we are working with moderate size files (size is not a problem though, however speed is) which would be a better programming approach(in terms of implementation, maintainence, and debugging the application), DOM or SAX ?

Thanks for all the inputs,