I need to read in a plain text file representing an arbitrary hierarchy of elements, where the elements are separated by newlines and the hierarchy structure is defined by tabs, like so: 
foo
    sub1
    sub2
        sub21
        sub22
bar
    camel

[download]
I would like to have my program generate the following hash tree from that text data: 
my $hash_tree = {
    foo => {
        sub1 => '',
        sub2 => {
            sub21 => '',
            sub22 => ''
        }
    },    
    bar => {
        camel => ''
    }
}

[download]
I have contemplated various recursive and iterative approaches to this problem, but have yet to come up with anything viable (ergo no code here).

Has anyone here done something similar before, or have a good idea of how to do it?

Thanks in advance, Bill

PS: if it makes a difference in how you would respond to such a question, I'll tell you that I'm proficient with C/C++, but am a relative beginner with Perl.

In reply to Reading an arbitrary hierarchy into a hash tree by XPhiNermal

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.