这个程序哪里不对?
#include "stdio.h"
#include "time.h"
#include "winsock.h"
int main()
{
char ch;
int result;
fd_set readset,tmpset;
struct timeval timeout;
FD_ZERO (&readset);
tmpset=readset;
scanf("%c",&ch);
timeout.tv_sec =5;
timeout.tv_usec =1000;
result=select(0, &tmpset ,NULL, NULL,&timeout);
if (result<0)
{
exit(0);
}
printf("%c",ch);
}