#command cdx binsearch -ktwo ccc $TMP/foo.txt $TMP/bar.txt
#infile foo.txt
 CDX	one	two	three
stuff	aaa	aaa
junk	bbb	zzz
things	ccc	aaa
aaa	ccc	zzz
zzz	ddd	aaa
aaa	eee	zzz
#infile bar.txt
 CDX	one	two	three
stuff	aaa	aaa
junk	bbb	zzz
111	ccc	222
333	ccc	444
zzz	ddd	aaa
aaa	eee	zzz
#stdout
 CDX	one	two	three
things	ccc	aaa
aaa	ccc	zzz
111	ccc	222
333	ccc	444