Irene He wrote:

> I've never used the return type as string (I don't remember if this
> type exsits in version before LV7), I always leave it as argument,
> because I know this way it always work. If as argument, you need to
> preallocate a space for the string.

It turns out you CAN have strings returned by functions- I looked through
the Comedi stuff and found a function that works that way, so I knew I
wasn't chasing something that will not work. It turns out I have a problem
passing null arguments; the function I started with can either take a null
argument to return the library version, or it can take a version as a string
in which case it only returns the version if it is greater.

The latter behaviour I can now get working, but what I thought was the
simpler case of not passing anything gives me no output. I've also tried
passing a string with /00 in it (in slash notation of course) but it doesn't
help.

Not a problem at the moment, but it would be useful to know how to pass null
to a function!

-- 
Dr. Craig Graham, Software Engineer
Advanced Analysis and Integration Limited, UK. http://www.aail.co.uk/





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