Is it possible to write a self-destructive program in C?

Question

Is it possible to write a program in C that upon execution deletes itself (the binary) and then terminates successfully. If so, what's the easiest way of doing this?

Answer 1

Yes.

#include <unistd.h>
int main(int argc, char* argv[])
{
  return unlink(argv[0]);
}

(Tested and works.)

Note that if argv[0] does not point to the binary (rewritten by caller) this will not work. Similarly if run through a symlink then the symlink, not the binary, will be deleted.

Also if the file has multiple hard links, only the called link will be removed.

Answer 2

I do not know that one can conveniently do it in a truly platform-independent way, but you didn't specify platform independence, so try the following, Linux-style code:

#include <stdio.h>
#include <unistd.h>

int main(int argc, char **argv) {
    printf("Read carefully!  You cannot print this message again.\n");
    return unlink(argv[0]);
}

How close is that to what you want?

Answer 3

If you operating system allows a running program to delete its own binary, then just look for the API for file deletion, or execute a corresponding system() command.

If the OS doesn't allow this, your program (let's call it A) could construct another binary, containing another program (let's call it B). Then, A would immediately quit.

Program B would have a single loop checking if A is still running and as soon as A quits, B would erase A's binary.