Re: Regular Expression multi-match not as expected

Hi Dennis,

I think you misunderstand how the 'match' array is used. (Because your code is working the way *I* expect, as well as the way it's documented to work.)

The first element of the array will contain the entire match of your pattern. The second element contains the match of the first subexpression, the third contains the match of the second subexpression, etc.

It will never show you multiple matches. Only the whole match, plus subexpressions. And in your example, you didn't use any subexpressions.

For a demonstration, though, try changing your 'findThis' variable as follows:

D findThis S 64 Varying Inz('(one).*(one)')

The parenthesis in my RE denote the subexpressions.

Keep the remaining code the same, just change that line. And run the program. Now you should get 3 elements in the array.

The first element would contain the starting/ending positions of the string 'none but the one' because that's the "whole pattern" match. The second element would contain the starting/ending positions of the 'one' from the word "none". (i.e. rm_so=10, rm_eo=13) The third element should contain the starting/ending positions of the word 'one' from the end of the sentence... i.e. rm_so=22, rm_eo=25.

Hope that makes sense. For a more "official" answer, see the ILE C Runtime Library manual from IBM, here:
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/topic/books/sc415607.pdf

IMHO, IBM doesn't do a great job of explaining it. You might try the man pages of your favorite Unix distro for a clearer explanation :)

On 2/3/2010 10:11 AM, Dennis Lovelady wrote:

Folks, I'm getting unexpected result from Regular Expression matching on
System i at V5R3. You can see the code in question at
http://code.midrange.com/e15d4eb99d.html.



I expect the expression to match on both the word "one" and the second
position of the word "none" but the search seems to stop after the first
match. (I can see that it has initialized all elements of match, however,
for whatever that's worth.) To see the issue, run in debug mode and set a
breakpoint at the line that contains "Match(es)". At that point, rc should
be zero (and it is); the first element of match should point to the second
character of done. (all good so far). But the second element of match
should point to the word "one" and it doesn't.



Can you see what might be wrong with this? Thanks.



Dennis E. Lovelady
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