bug#6903: join: improve paralleles to sort?

[Paul Eggert]

On 08/24/2010 12:39 PM, Bernhard Schiffner wrote:
> Because join uses strtoul() before doing comparisation it is understandable. 
> ("unpairable" is the result.)

No, join doesn't use strtoul.  It compares the numbers as strings.
So if you use plain "sort" on the numbers, join will work, unless the
numbers are numerically equal but textually different (e.g., 0 versus -0).
You can then sort the output of join with "sort -n", if you wish.

> Do you see a chance to extend join with a -n parameter for numeric 
> comparisation as sort has already?

That would be a nice thing to add, if someone had the time to do it.
Generally speaking, any comparison that "sort" can do, "join" should
do too (except for random comparison I suppose).

The comparison code between sort and join should be shared, of course.
Can you write that?