You are using the  -a switch which splits the fields on whitespace and puts them in  @F so you could write that as: 

echo '48 65 6c 6c 6f 2c 20 77 6f 72 6c 64 21' | perl -lane '$st .= chr
+ hex for @F; print $st;'

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In reply to Re^2: Basic transformations by jwkrahn
in thread Basic transformations by Anonymous Monk

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