Load a whole file in C with mmap

whole.c

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/mman.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main(int argc, char **argv) {
  char *filepath = argv[1];

  int fd = open(filepath, O_RDONLY);
  if (fd < 0) {
    perror("open");
    exit(1);
  }

  off_t size = lseek(fd, 0, SEEK_END);
  if (size < 0) {
    perror("lseek");
    exit(1);
  }

  char *content = NULL;
  content = mmap(content, size, PROT_READ, MAP_SHARED, fd, 0);
  fprintf(stdout, "%s", content);
  return 0;
}