#!/usr/bin/perl

use Data::Dumper;
use warnings;
use strict;

die("usage: $0 <key>=<value> [<key>=<value> ...]\n") unless @ARGV;

my %hash;
foreach my $set (@ARGV) {
    my($keys, $value) = split /=/, $set, 2;
    my @keys    = split /\//, $keys;
    my $lastkey = pop @keys;
    my $h       = \%hash;

    foreach my $key (@keys) {
        if (ref $h->{$key} eq 'HASH') { $h = $h->{$key}      }
        else                          { $h = $h->{$key} = {} }
    }

    $h->{$lastkey} = $value;
}

print(
    Data::Dumper
        ->new   ([\%hash])
        ->Useqq (1)
        ->Terse (1)
        ->Indent(1)
        ->Dump
);

[download]
An example usage: 

> ./create-nested-hash.pl foo/bar/baz=10 spam/eggs/ham=hi foo/stuff=20
+ top='Tophat!'
{
  "spam" => {
    "eggs" => {
      "ham" => "hi"
    }
  },
  "top" => "Tophat!",
  "foo" => {
    "bar" => {
      "baz" => 10
    },
    "stuff" => 20
  }
}

[download]

While this sort of thing is fun to write, be careful you don't create an unreadable mess. Data-driven programs are an excellent idea; data-driven data structures have a tendency to become unmanageable. The problem is it's far less understandable what the data structure looks like after you go through a few transformations.

In reply to Re: Assign a value to a hash of unknown nodes by Somni
in thread Assign a value to a hash of unknown nodes by jigglermwm

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.