Code Injection works in C# too!

Question

Given the following C# program outputting False, inject a 'malicious' line of code such that the program outputs True.

class Program
{
    static void Main()
    {
        System.Console.Write("False");
        ;
    }
}

Your answer should consist of a string that replaces the second semicolon, and causes the program to output True, the whole True and nothing but True (not even a newline). It must do this if stdout is printed to the console, and if stdout is redirected to a file.

The shortest answer wins.

Answer 1

52 characters

}static Program(){System.Console.Write(0<1);for(;;);

so the whole thing becomes:

class Program
{
    static void Main()
    {
        System.Console.Write( "False" );
    }
    static Program()
    {
        System.Console.Write( 0 < 1 ); 
        for ( ; ; ) ;
    }
}

Answer 2

C#, 51 characters

Console.Write("\b\b\b\b\b");Console.Write("True ");

Will only work on standard output

Answer 3

You can generalize RamonBoza's answer to still work if stdout is redirected to a file.

Assuming the program runs under Mono on Linux, with the assembly Mono.Posix.dll loaded:

if(Mono.Unix.Native.Syscall.isatty(1))
{
    Console.Write("\rTrue ");
}
else
{
    // Truncate the output file first
    Console.OpenStandardOutput().SetLength(0);
    Console.Write("True");
}

I doubt this works on Windows, but there's probably an equivalent to isatty().

Answer 4

83... WIP

I was hoping this'd work, but apparently "False" isn't being interned as I'd hoped in my compiler

//}unsafe static Program(){fixed(char*f="False"){*(long*)f=0x65007500720054;*(f+4)=' ';}
}unsafe static Program(){fixed(char*f="False")for(int i=5;i-->0;)*(f+i)="True "[i];

ungolfed

class Program
{
    static void Main(string[] args)
    {
        Console.Write("False");
    }

    unsafe static Program()
    {
        fixed (char* f = "False") for (int i = 5; i-- > 0; ) *(f + i) = "True "[i];
    }
}

Answer 5

class Program
{
    static void Main()
    {
        System.Console.Write("False");

        System.Console.Clear(); System.Console.Write("True");

        Console.ReadLine();
    }
}

Answer 6

Not sure if this is accepted.
The question doesn't say anything about compiler options so I assume I can change the entry point of the app.
55 characters ,3 more than the accepted answer

}class P{static void Main(){System.Console.Write(1>0);}

Full

class Program
{
    static void Main()
    {
        System.Console.Write("False");
    }
    class P
    {
        static void Main() { System.Console.Write(1 > 0); }
    }
}