I'm trying to map a hash over a filesystem so that the following is possible: 

    $root = $mysystem->root;
    $proc = $root->{'proc'};
    print "Uptime is ", $proc->{'uptime'}[0], "\n";

[download]

In other words, $mysystem->root returns a tied hash whose keys are the names of the files and directories in the root directory. However, I want the values to depend on the context. In scalar context: 

    $passwd = $root->{'etc'}->{'passwd'};
    $spool  = $root->{'var'}->{'spool'};

[download]
the value should be a reference to another tied hash of the same class.

In array context: 

    $line = $root->{'etc'}->{'passwd'}[0] # First line of passwd file
    @names = $root->{'var'}->{'spool'};   # List of files/dirs

[download]

the value should a tied array representing the entire file as an array of lines (if the key is a file name) or a list of the contents of the directory (if the key is the name of a directory)..

The problem is that using wantarray or looking at the caller() stack, I cannot seem to determine the context within FETCH; it's always scalar.

My question is: Within the FETCH method of a tied hash, is there any other way to distinguish between: 

    $proc->{'/var'}

[download]

and

    $proc->{'/var'}[0]

[download]

Thanks in advance for any help you can give!

In reply to How can one determine context within FETCH? by bluebutton

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.