<div><a href="http://anirudhagupta.blogspot.com/">Anirudha Web blog</a></div>
What is the Regular Expression to get http://anirudhagupta.blogspot.com/
from
<div><a href="http://anirudhagupta.blogspot.com/">Anirudha Web blog</a></div>
If you suggest in c# that's good i also like jQuery for do this.
HTML code is also means for a page who have a html code
Quick and dirty:
href="(.*?)"
Ok, let's go with another regex for parsing URLs. This comes from RFC 2396 - URI Generic Syntax: Parsing a URI Reference with a Regular Expression
^(([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
Of course, you can have relative URL address into your HTML code, you'll need to address them in another way; I can recommend you to use C# Uri Constructor (Uri, String).
The simplest way to do this is using the following regex.
/href="([^"]+)"/
This will get all characters from the first quote until it find a character that is a quote. This is in most languages the fastest way to get a quoted string, that can't itself contain quotes. Quotes should be encoded when used in attributes.
UPDATE: A complete Perl program for parsing urls would look like this:
use 5.010;
while (<>) {
push @matches, m/href="([^"]+)"/gi;
push @matches, m/href='([^']+)'/gi;
push @matches, m/href=([^"'][^>\s]*)[>\s]+/gi;
say for @matches;
}
It reads from stdin and prints all urls. It takes care of the three possible quotes. Use it with curl to find all the urls in a webpage:
curl url | perl urls.pl
If you want to use jQuery you can do the following.
$('a').attr('href')
you don't need complicated regex or HTML parser. since you only want to extract links. Here's a generic way to do it.
data="""
<html>
abcd ef ....
blah blah <div><a href="http://anirudhagupta.blogspot.com/">Anirudha Web blog</a></div>
blah ...
<div><a href="http://mike.blogspot.com/">Mike's Web blog
</a></div>
end...
</html>
"""
for item in data.split("</a>"):
if "<a href" in item:
start_of_href = item.index("<a href") # get where <a href=" is
print item[start_of_href+len('<a href="'):] # print substring from <a href onwards.
the above is Python code, but the idea behind you can adapt in your C# language. Split your html string using "</a>" as delimiter. Go thorough each splitted field, check for "href", then get the substr after "href". That will be your links.
The right way to do this is to load the html into the C# xml parser and then use xpath to query the URLs. This way you don't have to worry about parsing at all.