getchar() not returning any output-CodePudding

I was going through some basic C codes and then I found a program intended to count numbers from a given input:

#include <stdio.h>

// count characters given as input

int main()
{
    double nc;

    for(nc = 0; getchar() != EOF;   nc)
        ;

    printf("%.0f\n", nc);
}

But as I ran the program on terminal (I'm using Debian 11), I'm getting no output for whatever I give as input. But pressing Ctrl C is terminating the program as it should.

CodePudding user response：

I had to modify you code a little bit to make it work

#include <stdio.h>

#include <signal.h>

static volatile int keepRunning = 1;

void intHandler(int dummy) {
    keepRunning = 0;
}

// count characters given as input

int main()
{
   int nc = -1;
   signal(SIGINT, intHandler);
   while (keepRunning) { 
       nc = 0;
       for(nc = 0; getchar() != EOF;   nc)
           ;
    }
    if(nc != -1)
      printf("%i", nc);
}

pressing ctrl c will terminate the program before printing nc, so we have to catch the user pressing CTRL C, sing signal library
see this: Catch Ctrl-C in C

CodePudding user response：

I am using Win10, MS compiler, it worked fine...

C:\Users\Ahmed\Desktop>cl test.c
Microsoft (R) C/C   Optimizing Compiler Version 17.00.50727.1 for x86
Copyright (C) Microsoft Corporation.  All rights reserved.

test.c
Microsoft (R) Incremental Linker Version 11.00.50727.1
Copyright (C) Microsoft Corporation.  All rights reserved.

/out:test.exe
test.obj

C:\Users\Ahmed\Desktop>test.exe
adkjlad
asldkjasd
18
C:\Users\Ahmed\Desktop>