#command cdx uniq -k two -a three,min
#stdin
 CDX	one	two	three
aaa	bbb	ccc
ddd	bbb	eee
fff	bbb	ggg
hhh	ccc	iii
jjj	ccc	kkk
lll	ccc	111
#stdout
 CDX	one	two	three
aaa	bbb	ccc
hhh	ccc	111