#include <fcntl.h>

#include <stdio.h>

#include <stdlib.h>

#include <unistd.h>

#include <string.h>

#include <sys/errno.h>

#include <copyfile.h>      /* for copyfile(3)    */

#include <sys/clonefile.h> /* for clonefileat(2) */

int main(int argc, const char * argv[])

{

    int error;

    int was_cloned;

    copyfile_state_t s;

    if (argc != 3) {

        fprintf(stderr, "usage: %s src_file dst_file ...\n", argv[0]);

        exit(1);

    }

    /* Initailize state */

    s = copyfile_state_alloc();

    /* Copy the file (but clone if available)  */

    error = copyfile(argv[1], argv[2], s, COPYFILE_CLONE);

    if (error < 0) {

        perror("Error in copyfile()");

        exit(1);

    }

    /* Was the file cloned ? */

    if ((copyfile_state_get(s, COPYFILE_STATE_WAS_CLONED, &was_cloned) == 0) && was_cloned) {

        fprintf(stdout, "File was cloned\n");

    } else {

        fprintf(stdout, "File was copied and not cloned\n");

    }

    /* Release the state variable */

    copyfile_state_free(s);

    /* clone the file, this time using clonefileat(2) instead of copyfile(3) */

    (void)unlink(argv[2]);

    error = clonefileat(AT_FDCWD, argv[1], AT_FDCWD, argv[2], 0);

    if (error < 0) {

        perror("Error in clonefileat()");

        exit(1);

    }

    return (0);

}