Source code for a container that creates a large directory tree

Dockerfile

FROM ubuntu:bionic

RUN chmod 777 /tmp
RUN apt-get update && apt-get -y upgrade
RUN apt-get install -y git wget cmake sudo gcc-7 g++-7 python3-pip zlib1g-dev g++

RUN mkdir /code
COPY ./main.cpp /code
RUN g++ /code/main.cpp -o /code/a.out
RUN chmod +x /code/a.out

WORKDIR /code
ENTRYPOINT ["/code/a.out"]

main.cpp

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <cstring>
#include <sys/stat.h>
#include <sys/types.h>

int base = 256;

int main(int argc, char**argv) {
  char buf[256];
  memset(buf, 0, sizeof(buf));
  sprintf(buf, "garbage");
  int res = mkdir(buf, 0700);
  if (res != 0) {
    printf("Failed to create directory %s\n", buf);
  }
  for (int i=0; i < base; ++i) {
    sprintf(buf, "garbage/%d", i);
    int res = mkdir(buf, 0700);
    if (res != 0) {
      printf("Failed to create directory %s\n", buf);
    }
    for (int j=0; j < base; ++j) {
      sprintf(buf, "garbage/%d/%d", i, j);
      res = mkdir(buf, 0700);
      if (res != 0) {
        printf("Failed to create directory %s\n", buf);
      }
      for (int k=0; k < base; ++k ) {
        sprintf(buf, "garbage/%d/%d/%d", i, j, k);
        res = mkdir(buf, 0700);
        if (res != 0) {
          printf("Failed to create directory %s\n", buf);
        }
      }
    }
  }
  while(1) {
    printf("Printing a message, then sleeping a bit.\n");
    sleep(1);
  }
}