1/18/2011, "John W. Krahn" <jwkr...@shaw.ca> вы писали:
>Alexey Mishustin wrote:
>>
>> 1/18/2011, "Grant"<emailgr...@gmail.com> вы писали:
>>
>>> I came up with these but they don't seem to work reliably:
>>>
>>> /\.google\..*\/imgres\?/
>>> /\.google\..*\/images\?/
>>> /\.google\..*\/products\?/
>>
>> /(www.){0,1}(google\.).*\/(imgres)|(images)|(products)\?{0,1}/
>
>That says:
>
>(www.){0,1}
>
>Match a four character string, beginning with 'www', zero or one time,
>and store the match in $1
The point should be escaped as I wrote already. So, match the string
'www.', zero or one time.
>(google\.)
>
>Match the string 'google.' and store it in $2, Why? We know it will
>always be 'google.'.
>
>.*\/
>
>Match zero or more non-newline characters up to, and including, the last
>'/' character.
>
>(imgres)
>
>Match 'imgres' and store it in $3. Why? We know it will always be
>'imgres'.
>
>(images)
>
>Match 'images' and store it in $4. Why? We know it will always be
>'images'.
>
>(products)
>
>Match 'products' and store it in $5. Why? We know it will always be
>'products'.
>
>\?{0,1}
>
>Match a '?' character zero or one times.
I used brackets not for storing but for combining in order to use the
combined patterns in alternation.
>And finally, you use alternation which says to match either:
>
>(www.){0,1}(google\.).*\/(imgres)
>
>OR:
>
>(images)
>
>OR:
>
>(products)\?{0,1}
Oops. Evidently, I was wrong in this combining... I meant
(imgres)
OR
(images)
OR
(products)
--
Regards,
Alex
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