how to get particular string in .net

[dipalipatel]

hi

i have following string

string1="provider=pervasive oledb; datasource=test; location=mycomputer"

now i want to fetch the string
string2=test (i.e.= whatever in my datasource=)

and string3=mycomputer (i.e.=whatever in my location=)

also the string in string1 is not fixed
this is windows application in vb.net

Can anyone help me in finding the solution...

thanks in advance....

[Frinavale]

Use the String.Split() method and split the string on ";". This will give you an array of Strings and you can do with them as you please.

-Frinny

[balabaster]

or you could use regular expressions:

Dim str1 As String = "provider=pervasive oledb; datasource=test; location=mycomputer"
Dim str2 As String = Regex.Match(str1, "?i:(?<=datasource=)[^;]+(?=;)").Value

You could use the same idea for any of the settings, just replace datasource with the new item... i.e. for the location:

"?i:(?<=location=)[^;]+(?=;)"

Just to give you some clue as to what's going on, check out the regular expression cheat sheet for .NET found at: http://regexlib.com/CheatSheet.aspx

[Frinavale]

or you could use regular expressions:

I don't know why I always forget about regular expressions.
They are very handy especially with Strings.

Thanks Balabaster :)

[balabaster]

No problem... I can't count the number of times though where I've thought immediately to use regular expressions for something and then after having spent an hour trying to perfect a regular expression, I could've done something far quicker to implement... like by splitting a string into an array...

[kunal pawar]

I guess this is ur setting so ur application.
So datasource and other things are changed after installation.
So why ur not use app.config ?

[dipalipatel]

or you could use regular expressions:

Dim str1 As String = "provider=pervasive oledb; datasource=test; location=mycomputer"
Dim str2 As String = Regex.Match(str1, "?i:(?<=datasource=)[^;]+(?=;)").Value

You could use the same idea for any of the settings, just replace datasource with the new item... i.e. for the location:

"?i:(?<=location=)[^;]+(?=;)"

Just to give you some clue as to what's going on, check out the regular expression cheat sheet for .NET found at: http://regexlib.com/CheatSheet.aspx

Hi,
Thanks for your Answer.
But i am not sure which dll i need to add in my code so that i can get that method Regex.match.....
Can you send me that dll??

Thanks
Dipali

[kunal pawar]

u have to use
System.Text.RegularExpressions;

[dipalipatel]

u have to use
System.Text.RegularExpressions;

Thanks Kunal...
I tryed that and it gives me the follong error

parsing "?i;(<=Data Source=)[^;]+(?=;)" - Quantifier {x,y} following nothing.


Can you help with this?

Thanks

[balabaster]

The symbol after the ?i at the beginning should be a colon (:) not a semi-colon (;)...

[dipalipatel]

The symbol after the ?i at the beginning should be a colon (:) not a semi-colon (;)...

Hi

I did that but still i get the error. So, here is what i did:

My Original string:
mystr ="Provider=PervasiveOLEDB;Data Source=BBData;Location=MyComputer"

Part of string that i want as below:
Getstr = System.Text.RegularExpressions.Regex.Match(mystr, "?i:(<=Data Source=)[^;]+(?=;)").Value;

Error:
parsing "?i:(<=Data Source=)[^;]+(?=;)" - Quantifier {x,y} following nothing.

Can you help with this?

Thanks

[balabaster]

Oops, I missed another omission in your match string:

string MatchString = "(?i:(?<=Data Source=)[^;]+(?=;))";

Replace your match string with that...you didn't copy it right originally...

You missed a ? before <=Data Source and you need to wrap your string in another set of parenthesis...

[dipalipatel]

Oops, I missed another omission in your match string:

string MatchString = "(?i:(?<=Data Source=)[^;]+(?=;))";

Replace your match string with that...you didn't copy it right originally...

You missed a ? before <=Data Source and you need to wrap your string in another set of parenthesis...

Hey, You are great!!!

Thanks a Lot for your Solution.
Actually i was looking for a 1 line solution instead of Split and all function.
I Appreciate your help

Once again Thanks a lot...

[balabaster]

Hey, You are great!!!

Thanks a Lot for your Solution.
Actually i was looking for a 1 line solution instead of Split and all function.
I Appreciate your help

Once again Thanks a lot...

Well a one line solution would just involve putting the regex into a method something like:

private string SettingsString = "Provider=pervasive oledb; Data Source=test; Location=mycomputer";
 
public string GetSetting(string SettingName)
{
    return Regex.Match(SettingsString, String.Format("?i:(?<={0}=)[^;]+(?=;)").Value, SettingName));
}

From which you could extract each setting as easily as:

public main()
{
    string strDS = GetSetting("Data Source");
    string strProv = GetSetting("Provider");
    string strLoc = GetSetting("Location");
}

Piece of cake really...

[dipalipatel]

Well a one line solution would just involve putting the regex into a method something like:

private string SettingsString = "Provider=pervasive oledb; Data Source=test; Location=mycomputer";
 
public string GetSetting(string SettingName)
{
    return Regex.Match(SettingsString, String.Format("?i:(?<={0}=)[^;]+(?=;)").Value, SettingName));
}

From which you could extract each setting as easily as:

public main()
{
    string strDS = GetSetting("Data Source");
    string strProv = GetSetting("Provider");
    string strLoc = GetSetting("Location");
}

Piece of cake really...

Hi !!
Very Nice Solution
but Regex.Match has only 2 arguments in string, the 3rd one is System.Text.RegularExpressions.RegexOptions ..
And in Soutions you pass 3 Strings, So it gives an error regarding that 3rd arg.

[balabaster]

Not so much an extra setting as a ) in the wrong place:

        public static string GetSetting(string SettingName) 
        { 
            return Regex.Match(SettingsString, String.Format("(?i:(?<={0}=)[^;]+(?=;|$))", SettingName)).Value; 
        } 
 
        static void Main(string[] args)
        {
            string strDS = GetSetting("Data Source");
            string strProv = GetSetting("Provider");
            string strLoc = GetSetting("Location");
 
            Console.WriteLine(strDS);
            Console.WriteLine(strProv);
            Console.WriteLine(strLoc);
            Console.ReadKey();
        }

I made one slight modification to the match string also - because it wouldn't pick up the last setting if you omitted the closing ";", I added an "|$" after the ";" so that it would check for ; or end of string.

Sorry, usually I try and test my code before posting it, but I didn't have access to Visual Studio when I posted last time...

[dipalipatel]

It's Working ...
Great..

Thanks... a lot once again