using System;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		            string s = @"/s:http://a...content-available-to-author-only...d.asd /e:device /f:create";
 
                            string reg1 = @"(?=/s:)[^< ]+";
                            string reg2 = "(?=/e:)[^< ]+";
                            string reg3 = "(?=/f:)[^< ]+";
 
                            Match match1 = Regex.Match(s, reg1, RegexOptions.IgnoreCase);
 
                            if (match1.Success)
                            {
                                string key1 = match1.Groups[0].Value.Substring(3);
                                Console.WriteLine(key1);
                            }
 
                            Match match2 = Regex.Match(s, reg2, RegexOptions.IgnoreCase);
 
                            if (match2.Success)
                            {
                                string key2 = match2.Groups[0].Value.Substring(3);
                                Console.WriteLine(key2);
                            }
 
                            Match match3 = Regex.Match(s, reg3, RegexOptions.IgnoreCase);
 
                            if (match3.Success)
                            {
                                string key3 = match3.Groups[0].Value.Substring(3);
                                Console.WriteLine(key3);
                            }
	}
}

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