getuserkeyfromargv(userkey,szKey);  //生成密钥

//打开加/解密文件流

   if ((fp=fopen(filename,"r+b"))==NULL)

   {

      printf("\nError opening File %s\n",filename);

      exit (-1);

   }

//打开辅助文件流

   if ((temp=fopen(tempfilename,"w+b"))==NULL)

   {

      printf("\nError opening temporary file\n");

      exit(-1);

   }

// 直接对文件加/解密

   if (to_or_from==1)

   {

      printf("\nEncoding file %s   ",filename);

      cipher_file(fp,temp,userkey);

   }

   else    //  生成独立的加/解密文件

   {

      printf("\nDecoding file %s   ",filename);

      decipher_file(fp,temp,userkey);

   }

//用完文件,关闭文件流

   fclose (fp);

   fclose(temp);

   swap_files_and_clean_up(filename);

   system("PAUSE");

    }while(1);

}