QtScript output redirection

Question

When I call this code:

QScriptEngine e;
e.evaluate("print('hello, world!')");

the output text (from print method) is written to main application's terminal.

Is there any way to redirect it to a custom QIODevice?

Answer 1

You can replace print() with your own implementation:

First, define a C++ function that does what you want. In this case, it's just empty for exposition:

QScriptValue myPrint( QScriptContext * ctx, QScriptEngine * eng ) {
    return QScriptValue();
}

Then install that function as your new print():

QScriptEngine e = ...;
e.globalObject().setProperty( "print", e.newFunction( &myPrint ) );
e.evaluate( "print(21);" ); // prints nothing

Answer 2

The output text goes to stdout, so you need to redirect stdout. For ideas see this question. Best ideas: use reopen to redirect to a FILE*, or (better) use rdbuf to redirect stdout to some other stream derived from std::ostream, and you could play with QFile.open(1,...)-