There is Filesys::Virtual (and its subclasses), but I think not even that supports readdir on itself.

I'm not sure a string would be a good approach as an API. I would expect more something like a tied FH, calling various methods on the tied object to return directory entries. But so far, I have not seen a good abstraction for filesystems.

> Filesys::Virtual

does it implement anything? I looked into the code b/c of missing documentation and all subs look like this

sub login {
        my ($self, $username, $password) = @_;
         
        carp ref($self)."::login() Unimplemented";
         
        return 0;
}
[download]

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}

I think you want to look at its subclasses, like Filesys::Virtual::Plain or Filesys::Virtual::SSH for actual implementations.

secondary: Powershell has some cool features based on directory abstraction of recursive structures, like cd registry-key and navigating it like a filesystem.

Actually, I think porting Perl to work on top of GVfs, could be an interesting project.

primary: this question "glob an array?" would be trivial if we could chdir DH to a directory-handle which abstracts an array and glob it

Note that glob under the hood is loading and calling File::Glob, and if you study the code for this module you will see it already has hooks in place to support user defined opendir, readdir and closedir operations. But then, those hooks are not exposed at the Perl level!

Then you also have Text::Glob.

But is there a way to do it with opendir ,too?

No; the ability to open a variable as a file is derived from PerlIO (and is only available if your perl was built with PerlIO, which has been default since 5.8) and PerlIO only handles byte-streams and not directory-streams. On a related note, you cannot tie directory handles either when I last checked.

$ perl -e '$str="foo";' \
       -e 'open FH, "<", \$str or die "open: $!";' \
       -e 'print "var:   ",join(":",PerlIO::get_layers(FH)),"\n";' \
       -e 'print "STDIN: ",join(":",PerlIO::get_layers(STDIN)),"\n";'
var:   scalar
STDIN: unix:perlio

I assume that you would have to have some way to specify what file system the directory entries in your string are based on?   Or would you assume that they are the same as the root file system?

And what would the inode numbers point to?

> I assume that you would have to have some way to specify what file system the directory entries in your string are based on?

No, rather a minimal abstraction of a file system.

Kind of a nested data-structure like a AoA or HoH, not the full implementation.

> And what would the inode numbers point to?

nowhere? stat doesn't work on abstracted FH either, hence no "inode"

  DB<410> $str = join "\n", a..d

  DB<411> open AFH, "<",\$str

  DB<412> p "".<AFH>
a

  DB<413> p "".<AFH>
b

  DB<414> @stat = stat AFH

  DB<415> x @stat
  empty array
  DB<416>
[download]

see also stat: "Not all fields are supported on all filesystem types."

Cheers Rolf
_{(addicted to the Perl Programming Language :)
Wikisyntax for the Monastery}