函数名: int86x 
 功  能: 通用8086软中断接口 
 用  法: #include <dos.h> 
         int int86x(int intr_num, union REGS *insegs, union REGS *outregs, struct SREGS *segregs); 
 程序例: 
#include <dos.h> 
 #include <process.h> 
 #include <stdio.h> 
int main(void) 
 { 
    char filename[80]; 
    union REGS inregs, outregs; 
    struct SREGS segregs; 
   printf("Enter filename: "); 
    gets(filename); 
    inregs.h.ah = 0x43; 
    inregs.h.al = 0x21; 
    inregs.x.dx = FP_OFF(filename); 
    segregs.ds = FP_SEG(filename); 
    int86x(0x21, &inregs, &outregs, &segregs); 
    printf("File attribute: %X\n", outregs.x.cx); 
    return 0; 
 }