ModuleException and use in ModuleI3Status

Program.cs

@@ -42,6 +42,9 @@ namespace i3csstatus {
 			Color? color=null
 		);
 
+	class ModuleException: Exception
+	{
+	}
 	[System.AttributeUsage(System.AttributeTargets.Class, AllowMultiple = true)]
 	public class ModuleName : System.Attribute
 	{
@@ -82,6 +85,13 @@ namespace i3csstatus {
 	[ModuleName("i3status")]
 	class ModuleI3Status: Module
 	{
+		class ModuleI3StatusException: ModuleException
+		{
+			public override string ToString()
+			{
+				return $"I3Status don't work correctly.";
+			}
+		}
 		string name;
 		string configuration;
 		Element[] elements;
@@ -131,9 +141,13 @@ namespace i3csstatus {
 			public override void GetBegin()
 			{
 				process.KillBySignal(10);
-				string str = process.StandardOutput.ReadLine()[1..];
-				Console.WriteLine(str);
-				JsonArray json = JsonObject.Parse(str).AsArray();
+				string line = process.StandardOutput.ReadLine();
+				if(line == null)
+				{
+					throw new ModuleI3StatusException();
+				}
+				Console.WriteLine(line[1..]);
+				JsonArray json = JsonObject.Parse(line[1..]).AsArray();
 				if(json.Count != modules.Count)
 					throw new Exception("Parse i3status error");
 				for(int i=0;i<modules.Count;i++)