shithub: kwa

ref: 11e0cd792213373300d37a6a7ad3157f28416299
dir: /test/p.35/

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