Charles,
hereby a piece of code I used (c++).
input char_compressed, output char_decompressed, input
max_ll_char_decompressed
Hope this helps and sorry for comments in italian language.
Best regards.
Massimo Biancucci
/* ------------------------------------------------------------------ */
/* Esegue decompressione RLE come da macro CSRCESRV */
/* ci si aspetta di avere una stringa compressa in tal maniera */
/* in output la stringa su output e la lunghezza del buffer di uscita */
/* se < 0 abbiamo incontrato un errore */
/* ------------------------------------------------------------------ */
short rle_decode(char *input, char *output, unsigned short ll_i )
{
unsigned short i, j, i_i, i_o, i_copy;
char car;
if (input[0] ^= 0x80)
{
printf("Errore in rle_decode - Il buffer non e' compresso con rle");
return -1;
}
i_i = 1;
i_o = 0;
while (i_i < ll_i)
{
i_copy = input[i_i] & 0x7F;
if ((input[i_i] & 0x80) == 0x80) /* si tratta di una ripetizione */
{
car = input[i_i + 1];
for (i = 0; i < i_copy; i++)
{
output[i_o + i] = car;
}
i_o = i_o + i_copy;
i_i = i_i + 2;
}
else /* si tratta di fare una copia dei prossimi bytes */
{
for (i = 0; i < i_copy; i++)
{
i_i++;
output[i_o + i] = input[i_i];
}
i_i++;
i_o = i_o + i_copy;
}
}
return i_o;
}
2013/6/11 Charles Mills <[email protected]>
> Thanks. Yes, the compressed data clearly starts out with 80 followed (in my
> case) by a run count 7f of uncompressed characters. After that, I can kind
> of see some pattern but I am a long way from totally figuring it out. It
> would take some real experiments to do so (as opposed to my just looking at
> my existing data) -- or a post here or a private note from someone who has
> already done those experiments.
>
> Charles
>
> -----Original Message-----
> From: IBM Mainframe Discussion List [mailto:[email protected]] On
> Behalf Of Massimo Biancucci
> Sent: Tuesday, June 11, 2013 9:12 AM
> To: [email protected]
> Subject: Re: Anyone familiar with how z/OS CSRCESRV works?
>
> Hi,
>
> in the past I had to look at such a tricky because CICS write SMF with RLE
> if requested and I had to uncompress data on a PC.
>
> The compressed buffer must start with x'80' else it's not compressed with
> RLE (so the first character must be x'80' and you have to analyze from the
> second one for the real string).
>
> The escape character should be (once again) x'80' and the maximum length
> for
> the repeat-count is one byte (max=255) .
>
> I'm not sure at 100%, it was a long ago.
>
> Hope this helps.
>
> Best regards.
>
> Massimo
>
>
> 2013/6/11 Charles Mills <[email protected]>
>
> > Is anyone familiar with the "internals" of CSRCESRV run-length
> compression?
>
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