Thread: this version of getchar/putchar removes a character from output

So here is short/simple program that just takes your keyboard input, and outputs it when you press enter:

Code:

#include<stdio.h>
#include<stdlib.h>


int main()
{
   int c = getchar();


   while(c != EOF)
   {
      putchar(c);
      c = getchar();
   }
}

In "The C Programming Language" book, the author says doing this is more terse equivalent:

Code:

int main()
{
   int c = getchar();


   while((c = getchar()) != EOF)
   {
      putchar(c);
   }
}

However, the behavior is slightly different, on the first input, it removes a character. I can't figure out why:

Code:

a

abc
abc