Regular Expression problem.

Hi I've a regex / MatchRegularExpression() problem, hope you can help.

server is string = "ReferralServer: whois://whois.ripe.net:43"
m1,m2,m3 are strings
//"
IF MatchRegularExpression(server," ( [ReferralServer: whois://]{1,1} ) ( [a-zA-Z]+... 
[.][-a-zA-Z0-9]+ [.] [a-zA-Z]+ ) ( [:][0-9]* ) ", m1,m3,m3) THEN
	Trace(m1 + TAB + m2 + TAB + m3)
ELSE
	Trace("RegEx Error")
END

What I expect is
m1 = "ReferralServer: whois://"
m2= "whois.ripe.net"
m3 = ":43"
Instead I get "RegEx Error". What's my mistake ?

Please note the portnumber, in this case :43, is optional !! Means not every string server contains a portinformation..

thanks in advance !
Bjoern

Hi Bjoern...

This one seems tp be doing what you want:

(ReferralServer: whois://)([ a-zA-Z]*.[ a-zA-Z]*.[ a-zA-Z]*)(:[0-9]*)

and to find it, as I'm sure you'll prefer to know how I did it, I used the regular expression testing utility I wrote a few years back and available on this page:

[fabriceharari.com]

It allows you to test regular expression for inputmask, extraction, and so on... So when you don't plan to become a regular expression guru and still needs them from time to time, it's a great tool

Best regards

Fabrice Harari
WinDev, WebDev, WinDev Mobile consulting

Hi Bjoern

it seems that my previous post didn't make it... So here it goes again...

I think that this expression matches your need:
(ReferralServer: whois://)([ a-zA-Z]*.[ a-zA-Z]*.[ a-zA-Z]*)(:[0-9]*)

I found it by testing using my regular expression utility available here:
http://fabriceharari.com/windev/windev_regularexpressions.htm

If you need to test/debug a regular expression, I find it a great tool, when like me you are not a regular expression guru

Best regards

Fabrice Harari
WinDev, WebDev, WinDev Mobile consulting

Hi Fabrice,
seems you share the joy of sunday afternoon programming
Yep, you're right, the [.] is nonsense ! later more
Unfortunately your regex don't work.

I think a single dot . should be described as backslash dot. \.
( See : WD expression régulière / Example didactique)

Another problem is due to the fact that in :
ReferralServer: whois://whois.ripe.net:43

the port (:43) is optional. Means some whois server are offering this info, some of them not.

So here I think the regex should be :
( (:[0-9]*)? ) or even better ( (:[0-9]{2,2}) ? )

Now the ? is undocumented but nevertheless in use . WD ex. reg. sample.
The ? means 0 or 1 time.

However still can get it to work maybe nesting f.i. (()) is not supported )

I miss some features in WINDEV s MatchRegularExpression()

like ^ from begin , $ from end, as well as | optional... May be I write my own regex engine.in D....will see.

Thanks
Björn

Hi Fabrice, strange, I've recompiled my mini app. using your regex. and now it works !
thanks again, björn (Time to play with the regex ..)

Hi Fabrice,
That was indeed a nasty problem. I've copied and pasted a string into the code editor.
This string contains a dead character. ouch!

.
I've learned 3 things.
1 You can use the ? for regex. ? means 0 or 1 expression
2 You can use {2, } means at least 2 expressions
both used here :

(:[0-9]{2,}?)

3 You better don't trust the online help... the regex section needs an update, wrong explaination, buggy source examples

Anyway, finally here the complete and clean source : enjoy

server is string = "ReferralServer: whois://whois.ripe.net:43"

IF MatchRegularExpression(server, ...
	"(ReferralServer: whois://)([-a-zA-Z0-9_]*.[-a-zA-Z0-9_]*.[a-zA-Z]*)(:[0-9]{2,}?)", m1,m2,m3) THEN

	Trace(m1 + TAB + m2 + TAB + m3)
ELSE

	Trace("RegEx Error")
END

Thanks, Björn