getchar() and stdin

Question

A related question is here, but my question is different.

But, I\'d like to know more about the internals of getchar() and stdin. I know that getchar() just ultimately c

Answer 1

getchar()'s input is line-buffered, and the input-buffer is limited, usually it's 4 kB. What you see at first is the echo of each character you're typing. When your press ENTER, then getchar() starts returning characters up to the LF (which is converted to CR-LF). When you keep on pressing keys without LF for some time, it stops echoing after 4096 characters, you have to press ENTER to continue.