Extract a substring from a string

Question

How can I extract substring "Amy Java" from below string in C#?

CN=Amy Java,OU=Singapore,OU=Users,DC=domain,DC=com

From the looks of it; it seems to be a LDAP string. In that case, you can definitely get domain name. — A3006, Oct 07 '16 at 05:53
I am getting the above string in a textbox and from that I need to extract the substring "Amy Java" — Zakir HC, Oct 07 '16 at 05:54

score 2 · Answer 1 · answered Oct 07 '16 at 06:05

2

This works for me:

var amyJavaText =
    "CN=Amy Java,OU=Singapore,OU=Users,DC=domain,DC=com"
        .Split(',')
        .Select(x => x.Split('='))
        .ToLookup(x => x[0], x => x[1])["CN"]
        .First();

answered Oct 07 '16 at 06:05

Enigmativity

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it's a bit of overkill but i like that you looked for the key – Doruk Oct 07 '16 at 06:07
I hope the name doesn't have any escaped/quoted `,` or `=` characters in... – Rawling Oct 07 '16 at 06:36
@Rawling - Yes, agreed. – Enigmativity Oct 07 '16 at 07:52

score 1 · Answer 2 · answered Oct 07 '16 at 06:04

1

it's all you need.

string result = str.Split(',')[0].Split('=')[1];

answered Oct 07 '16 at 06:04

Doruk

884
9
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score 0 · Answer 3 · answered Oct 07 '16 at 06:23

In addition to more generic way, you can create a Dictionary (in case of unique values in String provided) or List of KeyValuePair (for current string example) as follow:

var str = "CN=Amy Java,OU=Singapore,OU=Users,DC=domain,DC=com";

var dict = str.Split(',').Select(s=> s.Split('=')).ToDictionary(a => a[0].Trim(), a => a[1].Trim()); //Only if Key are unique 
var kvp =  str.Split(',').Select(s=> s.Split('=')).Select(a=> new KeyValuePair<string,string>( a[0].Trim(), a[1].Trim()));

Then you can use another Linq to select the key required.

var requiredValue = kvp.Where(u=> u.Key == "CN").Value;

will give you required value.

score 0 · Answer 4 · answered Oct 07 '16 at 06:24

private string[] FindKeyValue(string str, string key)
{
    return str.Split(",".ToCharArray())
        .Select(x => x.Split("=".ToCharArray()))
        .Where(x => x[0] == key).Select(x => x[1]).ToArray();
}

Assuming you want know the value of CN, OU, DC etc. The string you have, looks like a key value pair where "CN" is a key and "Amy Java" is a value. It seems that a key can be present multiple times in the string. Therefore you have more than one value for a key. Use it as follows:

var str1 = "CN=Amy Java,OU=Singapore,OU=Users,DC=domain,DC=com";
string[] valuesOfCN = FindKeyValue(str1, "CN");

If you want just a single value such as first value then use

var str1 = "CN=Amy Java,OU=Singapore,OU=Users,DC=domain,DC=com";
string firstValueOfCN = FindKeyValue(str1, "CN").First();

Extract a substring from a string

4 Answers4