shithub: kwa

ref: a288969bf6c2d73cb8e77ece798a6009ffb57d99
dir: /test/p.35/

BEGIN			{ FS = OFS = "\t" }
$4 ~ /^North America$/	{ $4 = "NA" }
$4 ~ /^South America$/	{ $4 = "SA" }
			{ print }