printf的输出问题
写一段简单的代码

#include "stdio.h"
#include "unistd.h"
int main()
{
while(1)
{
printf(".");
fprintf(stderr, "*");
usleep(10000);//us
}
return 0;
}

输出跟我的理解差距很大，为啥我的printf没有一次输出呢？谁能给解释下吗？
输出：

****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

C printf
[解决办法]
printf中没有\n 没有刷新缓冲区的缘故吧
[解决办法]
应该是输出缓冲区吧，printf的内容会放置到输出缓冲区内，只有遇到缓冲区满，或强制刷新，或遇到'\n'才会把输出缓冲区内的内容打印在屏幕上。可以加个fflush();强制刷新输出缓冲区
[解决办法]
ISO C requires the following buffering characteristics.

Standard input and standard output are fully buffered, if and only if they do not refer to an interactive device.

Standard error is never fully buffered.


[解决办法]
输出缓冲区未刷新的缘故，可以用fflush强制刷新：

#include "stdio.h"
#include "unistd.h"
int main()
{
    while(1) 
 
    {
        printf(".");
        fflush(stdout);
        fprintf(stderr, "*");
        fflush(stdout);
        usleep(10000);//us
    }
    return 0;
}

引用:

写一段简单的代码

#include "stdio.h"
#include "unistd.h"
int main()
{
while(1)
{
printf(".");
fprintf(stderr, "*");
usleep(10000);//us
}
return 0;
}

输出跟我的理解差距很大，为啥我的printf没有一次输出呢？谁能给解释下吗？
输出：

****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................****************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************************................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................

[解决办法]
在每个最后不带\n的printf后面加fflush(stdout);