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Forum Discussion

David_Homoney's avatar
David_Homoney
Icon for Nimbostratus rankNimbostratus
Mar 06, 2008

Regex in STREAM

So I am attempting to use regex with the stream profile in an iRule. I need this to catch all hrefs execpt for ones with a css file extension. I have tested this with regex buddy and it looks good, bu...
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hoolio's avatar
hoolio
Icon for Cirrostratus rankCirrostratus
Mar 06, 2008
Unfortunately, TCL only supports lookaheads in regexes--not lookbehinds (negative or positive). I ran into this issue this week. I ended up having to collect the response content, use a more permissive regex with the regexp command and parse the results to only replace the strings that needed to be replaced. It would have been a lot easier with lookbehinds and a stream rule. Ugh...

 

 

 

http://www.regular-expressions.info/lookaround.html

 

 

Finally, flavors like JavaScript, Ruby and Tcl do not support lookbehind at all, even though they do support lookahead.

 

 

 

 

Aaron