This should do it:
> txt
[1]
"\nhttp://www.mysite.com/system/empty.asp?P=2&VID=default&SID=421384237289476&S=1&C=18631";
[2]
"\nhttp://www.mysite.com/system/empty.asp?P=123&VID=default&SID=421384237289476&S=1&C=18643";
[3]
"\nhttp://www.mysite.com/system/empty.asp?P=342&VID=default&SID=421384237289476&S=1&C=18634\n";
[4]
"\nhttp://www.mysite.com/system/empty.asp?P=232&VID=default&SID=421384237289476&S=1&C=18645";
[5]
"\nhttp://www.mysite.com/system/empty.asp?P=2345&VID=default&SID=421384237289476&S=1&C=18254";
[6]
"\nhttp://www.mysite.com/system/empty.asp?P=257654&VID=default&SID=421384237289476&S=1&C=18732";
[7]
"\nhttp://www.mysite.com/system/empty.asp?P=22&VID=default&SID=421384237289476&S=1&C=18637";
[8]
"\nhttp://www.mysite.com/system/empty.asp?P=2463&VID=default&SID=421384237289476&S=1&C=18575\n";
> gsub("^.*asp.P=([[:digit:]]+).*$", '\\1', txt)
[1] "2" "123" "342" "232" "2345" "257654" "22" "2463"
>
On 8/13/07, Lauri Nikkinen <[EMAIL PROTECTED]> wrote:
> Dear R-users,
>
> How do I extract numbers between asp?P= and &VID from my txt vector? I have
> tried grep function with no luck.
>
> txt <- c("
> http://www.mysite.com/system/empty.asp?P=2&VID=default&SID=421384237289476&S=1&C=18631";,
> "
> http://www.mysite.com/system/empty.asp?P=123&VID=default&SID=421384237289476&S=1&C=18643";,
> "
> http://www.mysite.com/system/empty.asp?P=342&VID=default&SID=421384237289476&S=1&C=18634
> ","
> http://www.mysite.com/system/empty.asp?P=232&VID=default&SID=421384237289476&S=1&C=18645";,
> "
> http://www.mysite.com/system/empty.asp?P=2345&VID=default&SID=421384237289476&S=1&C=18254";,
> "
> http://www.mysite.com/system/empty.asp?P=257654&VID=default&SID=421384237289476&S=1&C=18732";,
> "
> http://www.mysite.com/system/empty.asp?P=22&VID=default&SID=421384237289476&S=1&C=18637";,
> "
> http://www.mysite.com/system/empty.asp?P=2463&VID=default&SID=421384237289476&S=1&C=18575
> ")
>
> The result should be like
> 2
> 123
> 342
> 232
> 2345
> 257654
> 22
> 2463
>
> Thanks,
> Lauri
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
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> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem you are trying to solve?
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