match first digits before # symbol

Question

How to match all first digits before # in this line

26909578#Sbrntrl_7x06-lilla.avi#356028416#2012-10-24 09:06#0#http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html#[URL=http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html]http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html[/URL]#<a href="http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html">http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html</a>#http://bitshare.com/?f=dvk9o1oz#http://bitshare.com/delete/dvk9o1oz/4511e6f3612961f961a761adcb7e40a0/Sbrntrl_7x06-lilla.avi.html

Im trying to get this number 26909578 My try

   string text = @"26909578#Sbrntrl_7x06-lilla.avi#356028416#2012-10-24 09:06#0#http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html#[URL=http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html]http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html[/URL]#<a href=""http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html"">http://bitshare.com/files/dvk9o1oz/Sbrntrl_7x06-lilla.avi.html</a>#http://bitshare.com/?f=dvk9o1oz#http://bitshare.com/delete/dvk9o1oz/4511e6f3612961f961a761adcb7e40a0/Sbrntrl_7x06-lilla.avi.html";

        MatchCollection m1 = Regex.Matches(text, @"(.+?)#", RegexOptions.Singleline);

but then its outputs all text

Answer 1

Make it explicit that it has to start at the beginning of the string:

@"^(.+?)#"

Alternatively, if you know that this will always be a number, restrict the possible characters to digits:

@"^\d+"

Alternatively use the function Match instead of Matches . Matches explicitly says, "give me all the matches", while Match will only return the first one.

Answer 2

Or, in a trivial case like this, you might also consider a non-RegEx approach. The IndexOf() method will locate the '#' and you could easily strip off what came before.

I even wrote a sscanf() replacement for C#, which you can see in my article A sscanf() Replacement for .NET .

Answer 3

If you dont want to/dont like to use regex, use a string builder and just loop until you hit the #.

so like this

StringBuilder sb = new StringBuilder();
string yourdata = "yourdata";
int i = 0;
while(yourdata[i]!='#')
{
   sb.Append(yourdata[i]);
   i++;
}

//when you get to that # your stringbuilder will have the number you want in it so return it with .toString();

string answer = sb.toString();

Answer 4

The entire string (except the final url) is composed of segments that can be matched by (.+?)# , so you will get several matches. Retrieve only the first match from the collection returned by matching .+?(?=#)