`getchar()` gives the same output as the input string

Question

I am confused by a program mentioned in K&R that uses getchar(). It gives the same output as the input string:

#include <stdio.h>  main(){     int c;     c = getchar();     while(c != EOF){          putchar(c);          c = getchar();     } } 

Why does it print the whole string? I would expect it to read a character and ask again for the input.

And, are all strings we enter terminated by an EOF?

Answer 1

In the simple setup you are likely using, getchar works with buffered input, so you have to press enter before getchar gets anything to read. Strings are not terminated by EOF; in fact, EOF is not really a character, but a magic value that indicates the end of the file. But EOF is not part of the string read. It's what getchar returns when there is nothing left to read.