Testing speed of ofstream and FILE*

iospeed.cpp

#include <iostream>
#include <fstream>
#include <stdio.h>


const int N = 1000*1000*10;

void f1() {
    std::ofstream out("out.txt", std::ios::binary);
    for (int i = 0; i < N; ++i) {
        out << i << ' ' << i << ' ' << i << '\n';
    }
}

void f2() {
    FILE *out = fopen("out.txt", "wb");
    for (int i = 0; i < N; ++i) {
        fprintf(out, "%d %d %d\n", i, i, i);
    }
    fclose(out);
}

int main(int argc, char **argv) {
    if (argc < 2) {
        fprintf(stderr, "invalid parameters");
        return 1;
    }
    if (argv[1][0] == '1')
        f1();
    else if (argv[1][0] == '2')
        f2();
    else {
        fprintf(stderr, "invalid parameters");
        return 1;
    }
    return 0;
}