fork and get VMA

report1.c

#include "stdio.h"
#include "stdlib.h"
#include "sys/types.h"
#include "sys/wait.h"
#include "unistd.h"

int runcmd(char *cmd) {
  FILE *fp;
  char buf[1035];

  fp = popen(cmd, "r");
  if (fp == NULL) {
    printf("Failed to run command\n");
    exit(1);
  }
  while (fgets(buf, sizeof(buf) - 1, fp) != NULL) {
    printf("%s", buf);
  }
  pclose(fp);

  return 0;
}

int main(void) {
  pid_t pid = -42;
  int wstatus = -42;
  int ret = -1;
  char cmd[1024];

  pid = fork();
  switch (pid) {
    case -1:
      perror("fork");
      return EXIT_FAILURE;
    case 0:
      sleep(1);
      printf("[child]: my id [%d]\n", getpid());
      exit(0);
    default:
      printf("[father]: my id [%d]\n", getpid());
      printf("[father]: my child id [%d]\n", pid);
      sprintf(cmd, "cat /proc/%d/maps", pid);
      runcmd(cmd);
      break;
  }
  ret = waitpid(pid, &wstatus, 0);
  if (ret == -1) {
    perror("waitpid");
    return EXIT_FAILURE;
  }
  printf("Child exit status: %d\n", WEXITSTATUS(wstatus));
  return EXIT_SUCCESS;
}