Inputting EOF notation when using getch() for standard input

Question

here is a fragment of my program

     #include<stdio.h>
#include<conio.h>
int main(void)
{
    int c;
    while ((c = getch()) != EOF)
    {
        if (c == '\t')
        {
            putchar('\\');
            putchar('t');
        }
        else if (c == '\b')
        {
            putchar('\\');
            putchar('b');
        }
        else if (c == '\\')
        {
            putchar('\\');
            putchar('\\');
        }
        else if (c == '\r')
        {
            puts("\\n");
          //  putchar('\n');
        }
        else{
            putchar(c);
        }
    }
    return 0;
}

and I want to terminate my input when I input EOF, but when I input ^Z I only get this: enter image description here so how can I input ^Z to terminate my input?

What's the type of `c`? It should be `int`. If it's `char`, then it can never be `EOF`. — Mike Seymour, Nov 13 '14 at 08:20
@MikeSeymour The code doesn't matter and is redundant, the question is more about the CMD terminal than the program in question. It's actually better suited to SuperUser.com — sashoalm, Nov 13 '14 at 08:21
The EOF you're testing for in the `while` condition is not an EOF *character*, it's an actual end of file... or closed input stream, etc. — Dmitri, Nov 13 '14 at 08:22
Found something related (I guess (-;): http://stackoverflow.com/questions/7373386/eof-in-windows-command-prompt-doesnt-terminate-input-stream — Robert, Nov 13 '14 at 08:22
@sashoalm: Unless the problem is that `c` is the wrong type, which is one possible cause of the described symptoms. — Mike Seymour, Nov 13 '14 at 08:22
Also see https://stackoverflow.com/questions/16136400/how-to-send-eof-via-windows-terminal — sashoalm, Nov 13 '14 at 08:25

Serge Ballesta · Answer 1 · 2014-11-13T13:18:21.880

Your program works perfectly ... but getch does not do exactly what you expect.

getch (from conio.h) and getchar (from stdio.h) both get one character at a time, but not at same level. getchar is higher level, and so :

reads on stdin (can be redirected)
waits for a full buffer in line oriented mode
is interrupted by a Ctrl-C (more exactly Ctrl-C is seen as a SIG_INT signal)
translates special characters Ctrl-D on Unix-Linux Ctrl-Z on Windows as EOF

On the other hand, getch is low-level (and exists in Microsoft systems but is not standard C) :

directly reads on the keyboard
pass any character including Ctrl-C and Ctrl-Z as is
the only possible interruption is via Ctrl-Break
never returns EOF ( == -1)

All examples using getch works the same : you define what will be your end of input character and manually test it, there is no magical EOF.

Inputting EOF notation when using getch() for standard input

1 Answers1