Use a regex like this one:
_id=([a-f0-9]+)&
The parenthesis define a group which you can retrieve from the results.
Drew Noakes
2009-09-19 20:29:26
+3
A:
+4
A:
id=([^&]*)&
The data between id= and & will be matched by the first (and only) group and then be accessible via .group(1) or similar depending on the language/regex library.
Edit: Changed + to * as per Johannes Rössel's suggestion.
sepp2k
2009-09-19 20:30:37
Make the `+` a `*` to avoid strange results when id is empty under some weird circumstances.
Joey
2009-09-20 08:46:52
A:
I'd use
perl -ne 'm/[&?]_id=([^&]+)(&|$)/ && print $1;' [file]
where [file] is the name of the file containing the data.
nicerobot
2009-09-19 21:00:12
good catch - the end-of-string would break everyone else's regexps. i'd still recommend using a cgi param parsing utility, since there's a good chance your language ships one with the stdlib and it'll have taken care of the edge cases.
Martin DeMello
2009-09-20 09:43:13
+1. YOu have just convinced me that I need to practice my regexps. I would not have covered all your cases if I had written a similar regexp today.
Jørgen Fogh
2009-09-20 11:33:55
Brad Gilbert
2009-09-20 16:16:47
Brad Gilbert
2009-09-20 00:36:45
Could you please explain why that is the case? Is it because of the greedy vs non-greedy matching?
rk
2009-09-20 09:45:44