구조체 질문있습니다!

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <string.h>
#include <stdio.h>
 
struct userInfo
{
        char ID[10];
        char pw[15];
};
 
void makeUserInfo(struct userInfo *uinfo, char *ID, char *pw)
{
  memset((void *)uinfo, 0x00, sizeof(struct userInfo));
        strcpy(uinfo->ID, ID);
        strcpy(uinfo->pw, pw);
}
 
int main()
{
  int fd;
  struct userInfo linuxusr;
  int i;
  char ID[10];
  char pw[15];
 
  fd=open("member.txt", O_CREAT|O_WRONLY, S_IRUSR|S_IRGRP|S_IWGRP);
  if(fd<0)
  {
        perror("Error while opening file");
        return 1;
  }
 
  for(i=0;;i++){
  printf("Type the user id: ");
  scanf("%s",ID);
  fflush(stdin);
  printf("Type the password: ");
  scanf("%s",pw);
  fflush(stdin);
 
  makeUserInfo((void *)&linuxusr, ID, pw);
  write(fd, (void *)&linuxusr, sizeof(linuxusr));
  }
 
  close(fd);
  return 0;
}