String manipulation to truncate string up to a specified expression on C#

How do I remove more than three spaces from each line and end the string right there to look the line on the right using c#?

[Example1]  
PO BOX XXX 开发者_开发问答                                      OVERDUE - PAY NOW  
then transform to  
PO BOX XXX

[Example2]  
ClientB                                AMOUNT CARRI  
then transform to  
ClientB  

[Example3]  
PO BOX 400                                                    FORWARD TO N  
then transform to  
PO BOX 400  

var firstColumn = origString.SubString(0, origString.IndexOf("   "));

input = "PO BOX XXX                                       OVERDUE - PAY NOW  ";
input = input.Remove(input.IndexOf("   "));

there are 3 spaces in the indexOf paranthesis

Or you can do a split if you dont know if there is a tab or space -

input = input.Split(new char[] {' ', '\t'}, StringSplitOptions.RemoveEmptyEntries)[0];

You can do this:

var input = new string[3] { "PO BOX XXX                                       OVERDUE - PAY NOW  ", 
                                      "ClientB                                AMOUNT CARRI",
                                      "PO BOX 400                                                    FORWARD TO N  "
                                    };

    for (int x = 0, len = input.Length; x != len; x++)
    {
         input[x] = Regex.Replace(input[x], @"\s{3}[^\n]+", string.Empty);
    }
     //input is ["PO BOX XXX","ClientB","PO BOX 400"]

Using linq:

 var output = input.Select(str => Regex.Replace(str, @"\s{3}[^\r\n]+$", string.Empty));

if you're reading this string from file, you can do this:

var file = @"D:\file.txt";
var lines = File.ReadAllLines(file);
var output = lines.Select(str => Regex.Replace(str, @"\s{3}[^\n]+$", string.Empty)); // is ["PO BOX XXX","ClientB","PO BOX 400"]

You can use the string.Split method which results the string[]. Basing on the array count you can take the elements u need.

string base string = "PO BOX XXX OVERDUE - PAY NOW";
string[] delimittedStringArray = baseString.Split(' ');
if(delimittedStringArray.Length > 3)
{
  // Take the data from array
}
else
{
  // Do what ever
}

// I am not sure whether it is Length or Count in the if condition.