making a text file to an hash array

changma_ha has asked for the wisdom of the Perl Monks concerning the following question:

hello all, I am a newbie in perl. i have a text file like:

a
2
b
4,5,6
c
d
e
45,657,-67
[download]

i want an output like

a => [2]
b =>[4,5,6]
c =>[]
d=> []
e=> [45,657,-67]
[download]

is it possible to make the text data into complex structure of hash array?.plz help me out asap.

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