Newlines

What do the text utilities on AIX have against following the manual and manipulating newlines properly? Is it just that AIX is from IBM, and IBM software is half-assed?

$ uname -a
AIX myhost 3 5 00C2D2804C00
$ echo " 1 2 3 4   5 2 1" | tr -s [:space:] '\n'
 1 2 3 4   5 2 1
$ echo " 1 2 3 4   5 2 1" | tr -s [:space:] '\012'
 1 2 3 4   5 2 1

$ echo " 1 2 3 4   5 2 1" | sed 's/ /\n/g'
n1n2n3n4nnn5n2n1

By properly, I of course mean “How GNU does it.”

$ uname -a
Linux myhost 2.6.9-55.ELsmp #1 SMP Fri Apr 20 17:03:35 EDT 2007 i686 i686 i386 GNU/Linux
$ echo " 1 2 3 4   5 2 1" | tr -s [:space:] '\n                                                                             '

1
2
3
4
5
2
1

$ echo " 1 2 3 4   5 2 1" | tr -s [:space:] '\012'

1
2
3
4
5
2
1
$ echo " 1 2 3 4   5 2 1" | sed 's/ /\n/g'

1
2
3
4


5
2
1

Turns out that tr(5) was not matching the class [:space:] or the class [:blank:], but would match and transform the single character ' ' (space). Still not sure WTF is up with sed(5). The simple solution to this problem, of course, is to avoid AIX.