#include <stdio.h>
#include <unistd.h>
#include <assert.h>
#include <fcntl.h>
#include <sys/types.h>
#include <string.h>

void
dowork()
{
    int fd = open("/tmp/file", O_WRONLY | O_CREAT | O_TRUNC, S_IRWXU);
    assert(fd >= 0);

    char buffer[20];
    sprintf(buffer, "hello world\n");

    int rc = write(fd, buffer, strlen(buffer));
    assert(rc == (strlen(buffer)));

    printf("wrote %d bytes\n", rc);

    fsync(fd);
    close(fd);
}

int
main(int argc, char *argv[])
{
    dowork();
    return 0;
}