程序代码：

#include <stdio.h>
int main(void)
{int j=0;

 char i;

 while((i=gethar())!=EOF)
     if (i=='\n')
         ++j;
     printf("%d",j);
     return(0);
}--------------------Configuration: stu - Win32 Debug--------------------
Linking...
c.obj : error LNK2001: unresolved external symbol _gethar
Debug/stu.exe : fatal error LNK1120: 1 unresolved externals
执行 link.exe 时出错.

stu.exe - 1 error(s), 0 warning(s)