(was slashes, now NFS devices)

[David Zink]

Or how's this common bit of code:

FILE *
get_temp_handle()
{
    static char tmpl[] = "./cctmpXXXXXX";
    char tmp[sizeof(tmpl)], *ptr;
    FILE *fp = 0;

    strcpy(tmp, tmpl); /* Initialize our template */
    ptr = mktemp(tmp); /* Get the tmp file name */

    if (ptr) /* If all possible names were not used up */
    {
        fp = fopen(ptr, "w+");  /* Open the file for update */
        unlink(ptr); /* Clean-up if we exit suddenly */
    }
    return fp;
}

Never mind the old-timey style, equivalent things are still valid nowadays,
and it does serve one useful added feature.

It test whether the current directory is remotely mounted with NFS.

-- David
If you've been around long, you know this technique.