Free memory to sound

import std.stdio;
import std.random;
import std.math;
import std.algorithm;
import core.sys.linux.sys.sysinfo;
import core.sys.linux.time;

void main()
{
    sysinfo_ info2;
    sysinfo(&info2);

    enum freeConst = 0.000001f;

    float firstFreeRam = info2.freeram * freeConst;

    writeln(firstFreeRam);

    enum sampleRate = 8000;

    float freq = 0f;
    float nextTime = 0f;

    for(int sample = 0; ; sample++) {
        float value = 0f;
        float time = sample / cast(float)sampleRate;

        //writeln("Sample:, ", sample, " Time: ", time);

        //float freq = sample / 100f + 50f;

        if(time > nextTime) {
            nextTime = time + 0.1f;

            sysinfo_ info;
            sysinfo(&info);

            freq = (info.freeram * freeConst - firstFreeRam) * -0.6f + 500f;
        }

        value = sin(2 * PI * time * freq);

        //writeln(cast(int)((clamp(value, -1f, 1f) * 0.5f + 0.5f) * 255f));

        write(cast(char)cast(int)((clamp(value, -1f, 1f) * 0.5f + 0.5f) * 255f));

        if(sample % (sampleRate / 5) == 0) {
            timespec ts;
            ts.tv_nsec = 200_000_000;
            nanosleep(&ts, &ts);
        }
    }
}