printf() prints only the first character

September 10, 2024

Recently I came across an example from the book "The C Programming Language" and decided to run it:

#include <stdio.h>

#define IN 1
#define OUT 0

int main() {

    int c, nl, nw, nc, state; 

    state = OUT; 
    nl = nw = nc = 0; 
    while ((c = getchar()) != EOF) {
        ++nc; 
        if (c == '\n') 
            ++nl;
        if (c == ' ' || c == '\n' || c == '\t') 
            state = OUT;
        else if (state == OUT) {
            state = IN; 
            ++nw;
        } 
    }
    printf("%d %d %d\n", nl, nw, nc);
}

There is a problem related to printf(). For some reason, only the first character is printed, although there should be 3 of them. What could be the problem?

System – Windows. For editing code I use Visual Studio Code. Compiler – gcc.

Interesting fact: on macOS this problem do not occur and the output is as needed.

Input:

a       
ab 
abc
abcd

Output:

Desired output:

4 4 14

Thanks in advance!

ANSWER:

I used control-C thinking that it was suitable as an EOF-indicator. The correct option is to use control-Z.

>Solution :

The idea here is:

to count letters, words and lines from the input file. Words are separated by spaces or tabs or newlines.
the program implements a minimalist FSM, a finite state machine with 2 states.

I am not sure I understand the question, but here is the output for this file