Using sed I want to replace space by newline

Shell Programming and Scripting
1

Input:
--------------------------
123asd 456sdasda 789a
-------------------------

output wanted:
---------------------
123asd
456sdasda
789a
----------------------

I want this by sed in simple way

please help (I know by: tr ' ' '\n' < inputfile )I want it by sed only

2 
sed 's/ /\n/g' infile
xargs -n1 < infile
3

file contain:
This is the best site I have never come across. The best one indeed.
Very best site to post queries.

SED NOT WORKING : sed 's/ /\n/g' file1

ThisnisnthenbestnsitenInhavenneverncomenacross.nThenbestnonenindeed.
Verynbestnsitentonpostnqueries.

other one works but I want in sed only.

4

sed in Solaris ?

sed 's/ /\
> /g' infile

after / /\, type enter

5

In a terminal the second line will be prompted with '>'

$ echo "123asd 456sdasda 789a" | sed 's/ /\
/g'

Result

123asd
456sdasda
789a

Alrady showed by rdcwayx, but his post didn't appezr while writing mine :o

6

To my knowledge, the \n escape sequence in replacement text is a gnu extension to the posix sed standard.