Porter gets caught by him (4)
I believe the answer is:
alec
'him' is the definition.
'porter gets caught' is the wordplay.
'porter' becomes 'ale' (I've seen this in other clues).
'gets' is a charade indicator (letters next to each other).
'caught' becomes 'c' (cricket abbreviation).
'ale'+'c'='ALEC'
'by' is the link.
(Other definitions for alec that I've seen before include "A smart . . . . is a know-all in lace" , "Smart chap" , "Guinness (a smart lad?)" , "Boy's name (a smart one?)" , "Smart boy?" .)