The first element of the list returned by stat will be different on a directory and its parent directory if and only if the directory is a mountpoint.

#!/usr/bin/perl

use strict;
use warnings;

use Cwd qw/realpath/;
use File::Spec;

my $Dir = realpath(shift || File::Spec->curdir);
my $Parent = realpath(File::Spec->catdir($Dir, File::Spec->updir));

my $Dir_fsid = (stat($Dir))[0];
my $Parent_fsid = (stat($Parent))[0];

printf 'dir: [on %4x] %s%s', $Dir_fsid,$Dir,"\n";
printf ' up: [on %4x] %s%s', $Parent_fsid,$Parent,"\n";

if ($Dir_fsid == $Parent_fsid) {
  print "$Dir is not a mountpoint\n"
} else {
  print "$Dir is a mountpoint\n"
}

__END__

[download]

In reply to Re: Check that a ramdisk is mounted by jcb
in thread Check that a ramdisk is mounted by pmilne

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.