extract unique pair combination

[Bart2009]

Hello,

I have a file with fields containing:

string1 string2
string1 string3
................
string3 string1
...............

I wish to extract all unique pair combinations like:
string1 string3

but not
string3 string1

using (preferred) ksh.

Thanks in advance,
Bart

[Dennis Handly]

awk '
{
if ($1 > $2) print $2, $1
else print $1, $2
}' file | sort -u

[Bart2009]

Thanks alot,

I was about to write a similar awk solution.
Your email arrived just in time.

Have a nice weekend,
Bart