stdio.h:#ifndef BUFSIZ
stdio.h:#define BUFSIZ _IO_BUFSIZ

libio.h:#define _IO_BUFSIZ _G_BUFSIZ
_G_config.h:#define _G_BUFSIZ 8192

1 //测试程序：
2 
3 #include <stdlib.h>
4 #include <stdio.h>
5 
6 int main()
7 {
8   printf("BUFSIZ= %d \n",BUFSIZ);
9 }