Thanks,
Jim
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/mman.h>
int main(void)
{
void *ptr;
char *fname = "/tmp/_my_test";
int fd = open(fname, O_WRONLY /*O_RDWR*/, 0600);
printf("Opened \"%s\" and got fd %d\n", fname, fd);
ftruncate(fd, 8192);
ptr = mmap(0, 8192, PROT_WRITE, MAP_SHARED, fd, 0);
printf("mmap of file returns 0x%lx\n", (unsigned long) ptr);
}