this program blocks, then waits for you to enter an integer, then outputs it as is, and then blocks again, and so on.
(compiler: VS2005)
-sharpinclude<stdio.h>
int main()
{
int i;
while(1)
{
puts("");
scanf("%d", &i);
printf(":%d\n", i);
}
}but in fact, if the typed letters are recycled back, they will not block, but will go on in a crazy loop.
Baidu found that the scanf function will take a piece of data from the input cache (I don"t know what this is). If I enter a number, this operation will empty the input cache. When running the scanf function again, if the input cache is empty, it will cause a block.
however, I still don"t understand what happens when you enter letters.