How can I extract a valid URL from a string like this one
h*tps://www.google.com/url?q=h*tp://www.site.net/file.doc&sa=U&ei=_YeOUc&ved=0CB&usg=AFQjCN-5OX
I want to extract this part: h*tp://www.site.net/file.doc, this is my valid URL.
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1Which bit do you what from the string?Ash Burlaczenko– Ash Burlaczenko2013-05-12 08:50:02 +00:00Commented May 12, 2013 at 8:50
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What do you mean with valid? Do you wont to replace the "*" with a "t" or what else?FeliceM– FeliceM2013-05-12 08:50:22 +00:00Commented May 12, 2013 at 8:50
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1Regex is the right way to go. Define the pattern that you want to extract, get the Regex's Matches and pick the one that you require.Saravanan– Saravanan2013-05-12 08:50:54 +00:00Commented May 12, 2013 at 8:50
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Thanks for your attentions, i edited the question.Naourass Derouichi– Naourass Derouichi2013-05-12 08:59:06 +00:00Commented May 12, 2013 at 8:59
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FeliceM, i replaced the t by the star because of the restriction of posting more than two link.. i'm new here! Thank you anyway this informationn can be usefull to me.Naourass Derouichi– Naourass Derouichi2013-05-12 09:03:27 +00:00Commented May 12, 2013 at 9:03
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4 Answers
Add System.Web.dll assembly and use HttpUtility class with static methods. Example:
using System;
using System.Web;
class MainClass
{
public static void Main (string[] args)
{
Uri uri = new Uri("https://www.google.com/url?q=http://www.site.net/file.doc&sa=U&ei=_YeOUc&ved=0CB&usg=AFQjCN-5OX");
Uri doc = new Uri (HttpUtility.ParseQueryString (uri.Query).Get ("q"));
Console.WriteLine (doc);
}
}
5 Comments
Ash Burlaczenko
With the protocol as
h*tps, would Uri parse the string correctly?
Denis
Uri parse the string correctly.
Ash Burlaczenko
Thats incorrect, tested and got an
Invalid URI: The URI scheme is not valid. exception.Denis
Whick version of .net/mono?
Ash Burlaczenko
5, the version is irrelevant, the class hasn't changed.
h*tps is not a valid protocol so how could it parse it?I don't know what your other strings can look like, but if your 'valid URL' is between the first = and the first &, you could use:
(?<==).*?(?=&)
It basically looks for the first = and matches anything before the next &.
Tested here.
Comments
You can use split function
string txt="https://www.google.com/url?q=http://www.site.net/file.doc&sa=U&ei=_YeOUc&ved=0CB&usg=AFQjCN-5OX";
txt.split("?q=")[1].split("&")[0];
in this particular case with the string you posted you can do this:
string input = "your URL";
string newString = input.Substring(36, 22) ;
But if the length of the initial part of the URL changes, and also the lenght of the part you like to extract changes, then would not work.
3 Comments
Naourass Derouichi
this is also usefull thanks:
FeliceM
You can replace the numbers (36, 22) with int variables and fix the value counting the character to a certain occurrence. My answer is very basic.
nhahtdh
@NaourassDerouichi: Please use the Uri class and ParseQuery utility to process the URL.