Re: [pcre-dev] issue with Posix on z/OS

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Auteur: Ze'ev Atlas
Datum:  
Aan: pcre-dev@exim.org
Onderwerp: Re: [pcre-dev] issue with Posix on z/OS
Thank you so much
I am sending you the results with both match and no match (added rubbish to same file :)
I will continue to look myself as well.
 
Ze'ev Atlas
201-801-0378
201-805-0286 (cell)


________________________________
From: "ph10@???" <ph10@???>
To: Ze'ev Atlas <zatlas1@???>
Sent: Tuesday, July 2, 2013 7:13 AM
Subject: Re: [pcre-dev] issue with Posix on z/OS


[Not sent to pcre-dev because of the attachment.]

On Mon, 1 Jul 2013, Ze'ev Atlas wrote:

> I wonder whether pcre_dfa_exec.c, pcreposix.h or pcreposix.c contain
> some reference to ASCII specific character or sequence that might
> cause it to balk on EBCDIC.


Good point. I've had a quick look at the posix code, and there's nothing
obvious therein. Let's concentrate on getting that working before
looking at DFA.

> I did find things like this in pcre_dfa_exec.c, which is obviously
> incorrect in EBCDIC context:


> <snippet>
> #ifdef PCRE_DEBUG
>     printf ("%.*sProcessing state %d c=", rlevel*2-2, SP, state_offset);
>     if (clen == 0) printf("EOL\n");
>       else if (c > 32 && c < 127) printf("'%c'\n", c);
>         else printf("0x%02x\n", c);
> #endif
> <snippet>


True, but that code just prints debugging output, and is not normally
included.

> or 
> <snippet>
>
> #ifndef EBCDIC
>           case 0x2028:
>           case 0x2029:
> #endif  /* Not EBCDIC */
> <snippet>
>
> which I do not know what to make of, but I do not think any of those
> caused the issue.


Those are Unicode data points which are obviously unavailable in EBCDIC
as their value is greater than 255. That's why they are cut out in
EBCDIC environments.

> The program crashes in a loop using the pchars function and I believe
> it is pcretest.c itself.


> <snippet> 
> The -p option cause it (pcretest) to get into an infinite loop of
> printing \x00 and ultimately crash when the program tries to write the
> next \x00 beyond the buffer size (I gave it 30K and it used all of
> them... the printout below just demonstrate the first 305 characters
> of the printout.) 


I've just studied the pchars() and pchar() functions in pcretest, and I
cannot see anything that might be causing this.

/the quick brown fox/                                                         
    the quick brown fox                                                       
 0:                                                                           
 1:                                                                           
\x00\x00\x00\x00\x00....

This indicates that the match worked, but that passing back the
information about the match went horribly wrong. I have attached a
modified version of pcretest.c that includes some debugging commands
that will print additional data, which might help.

It might be worth trying a test that fails to match, for comparison.
Feed pcretest -p a couple of lines like this:

/the quick brown fox/
rubbish

and see what happens.

Philip

--
Philip Hazel