正则表达式由目标字符串分割到某个字符

Question

I have an LDAP Query I need to build the domain.

So, split by "DC=" up to a "comma"

INPUT:
LDAP://DC=SOMETHINGS,DC=ELSE,DC=NET\\account

RESULT:
SOMETHING.ELSE.NET

Answer 1

You can do it pretty simple using DC=(\\w*) regex pattern.

var str = @"LDAP://DC=SOMETHINGS,DC=ELSE,DC=NET\account";
var result = String.Join(".", Regex.Matches(str, @"DC=(\w*)")
                                   .Cast<Match>()
                                   .Select(m => m.Groups[1].Value));

Answer 2

Without Regex you can do:

string ldapStr = @"LDAP://DC=SOMETHINGS,DC=ELSE,DC=NET\account";
int startIndex = ldapStr.IndexOf("DC=");
int length = ldapStr.LastIndexOf("DC=") - startIndex;
string output = null;
if (startIndex >= 0 && length <= ldapStr.Length)
{
    string domainComponentStr = ldapStr.Substring(startIndex, length);
    output = String.Join(".",domainComponentStr.Split(new[] {"DC=", ","}, StringSplitOptions.RemoveEmptyEntries));
}

If you are always going to get the string in similar format than you can also do:

string ldapStr = @"LDAP://DC=SOMETHINGS,DC=ELSE,DC=NET\account";
var outputStr = String.Join(".", ldapStr.Split(new[] {"DC=", ",","\\"}, StringSplitOptions.RemoveEmptyEntries)
                                .Skip(1)
                                .Take(3));

And you will get:

outputStr = "SOMETHINGS.ELSE.NET"