Why GNU coreutils/dd is creating a dummy file more efficiently than D's For loop?

[Daniel Kozak]

On Thu, May 23, 2019 at 11:10 AM BoQsc via Digitalmars-d-learn <
digitalmars-d-learn at puremagic.com> wrote:

> This code of D creates a dummy 47,6 MB text file filled with Nul
> characters in about 9 seconds
>
> import std.stdio, std.process;
>
> void main() {
>
>         writeln("Creating a dummy file");
>         File file = File("test.txt", "w");
>
>     for (int i = 0; i < 50000000; i++)
>         {
>                 file.write("\x00");
>         }
>     file.close();
>
> }
>
>
> While GNU coreutils dd can create 500mb dummy Nul file in a
> second.
> https://github.com/coreutils/coreutils/blob/master/src/dd.c
>
> What are the explanations for this?
>

https://matthias-endler.de/2017/yes/
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