I was looking for a value of "100.100.100.100"

Huh? From the code you gave, I assumed you were looking for a value of (100, 100, 100, 100) (i.e., a list of four values).

$;=sub{$/};@;=map{my($a,$b)=($_,$;);$;=sub{$a.$b->()}}
split//,".rekcah lreP rehtona tsuJ";$\=$ ;->();print$/
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