void doProgress(char* label, size_t step, size_t total) {
    //progress width
    const int pwidth = 60;

    //minus label len
    size_t width = pwidth - strlen(label);
    size_t pos = (step * width) / total;

    size_t percent = (step * 100) / total;

    printf("\r%s%4d/%4d [", label, step, total);

    int i;

    //fill progress bar with =
    for (i = 0; i < pos; i++) {
        printf("%c", '=');
    }

    //fill progress bar with spaces
    printf("% *c", width - pos + 1, ']');
    printf("%3d%%", percent);
    fflush(stdout);
}