#command cdx paste -e late $TMP/aaa $TMP/bbb -d zzz
#infile aaa
CDX one two three
111 222 333
11a 22b 33c
11x 22y 33z
#infile bbb
CDX four five six
444 555 666
44d 55e 66f
#stdout
CDX one two three four five six
111 222 333 444 555 666
11a 22b 33c 44d 55e 66f
11x 22y 33z zzz zzz zzz