shithub: kwa

ref: 279f78a86cbff3f526fe1a1debd4d4f5766f96b0
dir: /test/p.35/

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