CODEWITHSUNDEEP
cbashkill
Francesco Mantovani
Francesco Mantovani

Reputation: 12197

CTRL + C doesn't kill C script

I'm reading Operating Systems: Three Easy Pieces and I'm finding a problem is not mentioned in the book.

This is the C script:

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
/*#include "common.h"*/
#include <unistd.h>
#include <assert.h>


int
main(int argc, char *argv[])
{
    int *p = malloc(sizeof(int));
    assert(p != NULL);
    printf("(%d address pointed to by p: %p\n",
            getpid(), p);
            *p = 0;
            while (1) {
                sleep(1);
                *p = *p +1;
                printf("(%d) p: %d\n", getpid(), *p);
            }
            return 0;
}

It allocates some memory, prints out the address memory, puts the number 0 into it and finally loops to increment the value.

I compile it through gcc -o mem mem.c -Wall and I have no problem running it with ./mem, if I press CRTL+C it will stop:

enter image description here

But then problems come when I run the script twice in parallel with the command ./mem & ./mem, look at the GIF:

enter image description here

No matter how many times I try to kill the process the scripts keeps hammering.

How to kill my C which project?

Upvotes: 1

Views: 859

Answers (1)

John Kugelman
John Kugelman

Reputation: 361527

Use fg to bring the backgrounded process to the foreground, then it will respond to Ctrl-C.

You can also use jobs to see a numbered list of backgrounded jobs, and kill %<number> to kill a specific job, e.g. kill %1.

Upvotes: 1

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