Kernighan & Ritchie code example confusion

Question

Is there any reason of the second 'c = getchar()' mention in this code example?

#include <stdio.h>
/* copy input to output; 1st version */  

int main(void) {

    int c;

    c = getchar();
    while (c != EOF) {
        putchar(c);
        c = getchar(); // <-- I mean this one.
    }
    return 0;
}

Answer 1

c = getchar();                    //read for the first time before entering while loop
    while (c != EOF) {
        putchar(c);
        c = getchar();            // read the next input and go back to condition checking
    }
    return 0;

1. first getchar() reads the first time input character.
2. second getchar() keeps on reading next input(s), untill a EOF

In other words, the purpose of while (c != EOF) is to keep on checking whether the c is EOF or not. if c is not changed, then the while() loop is meaningless, isn't it? The second getch() is responsible for chnaging the value of c in each iteration.