Programming in D, page 62 - Problems with reading characters

[Brother Bill]

source/app.d is
```
import std.stdio;

void main() {
    char letter;

    write("Please enter a letter: ");
    readf(" %s", &letter);

    writeln("The letter that has been read: ", letter);
}
```

What are steps to type letter: ğ
in Fedora Linux using an American Keyboard?

Is there a document that indicates how to type many Unicode 
characters as a series of keystrokes?