github.com/benhoyt/goawk@v1.8.1/testdata/p.35 (about)

     1  BEGIN			{ FS = OFS = "\t" }
     2  $4 ~ /^North America$/	{ $4 = "NA" }
     3  $4 ~ /^South America$/	{ $4 = "SA" }
     4  			{ print }