#include <unistd.h>
#include <stdlib.h>
int main()
{
char buffer[128];
int nread;
nread = read(0,buffer,128);
if (nread == -1)/*如果nread等于-1報錯*/
       write(2,"A read error has occurred\n",26);
if ((write(1,buffer,nread))!=nread)
       write(2,"A write error has occurred\n",27);
  exit(0);
}