Translating RAD-50 code

Hi @ all,

I have files containing data encoded in RAD-50 format.
In this format, 3 characters (A-Z, 0-9, $, ., _, and blank
are stored in 2 bytes (so that each character is coded in
around 5 bits).

I have to read these files, process them and write out the
results again in RAD-50.

On the system, there is a shared library (under Linux, it
would be a .so, but it's VMS, so it's a .EXE), providing
routines to convert RAD-50 to ASCII and ASCII to
RAD-50.

Of course, I could write XS code containing two functions
to perform these conversions, place the XS code in a
module and load it using DynaLoader while use'ing it.

But I think this would be a perfect opportunity for an
IO-layer, so I (and others!) could simply write

open IN,'<:rad50',$input_file;

open OUT,'>:rad50',$output_file;

So my question is: is there documentation how to write
IO layers in XS? Some examples, guidelines?

MTIA for your answers, and kind greetings from Vienna

Ferry

--
Ing Ferry Bolhar
Magistrat der Stadt Wien - MA 14
A-1010 Wien
E-Mail: bol@xxxxxxxxxxxxxxxxx


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