isgraph ( )【C语言库函数源代码】

【C语言库函数源代码】

【本程序在Dev C++ 4.9.9.2 下编译通过】

int my_isgraph( int ch )

{

  return (unsigned int)(ch - '!') < 127u - '!';

}//判断字符c是否为除空格外的可打印字符。可打印字符（0x21-0x7e）。

int main()

{

   char ch = '_';

 

   if(my_isgraph(ch))

      printf("%c is a Graph Character\n",ch);

   else

      printf("%c is not a Graph Character!\n",ch);

 

   ch = '1';

 

   if(my_isgraph(ch))

      printf("%c is a Graph Character\n",ch);

   else

      printf("%c is not a Graph Character!\n",ch);

 

   ch = ' ';

 

   if(my_isgraph(ch))

      printf("%c is a Graph Character\n",ch);

   else

      printf("%c is not a Graph Character!\n",ch);

 

   system("pause");

   return 0;

}