COMM and Numerical Sorting

Shell Programming and Scripting
1

Hi,

Hope someone can shed some light on this...
I have two lists of numbers I am comparing using COMM. If the first list is empty, and I sort both lists like so:

DIFF=`comm -3 <(echo "$EMPTY" | sort -n) <(echo "$NUMBERS" | sort -n)`

I get the error: comm: file 2 is not in sorted order

But if I drop the numerical sorting from sort:

DIFF=`comm -3 <(echo "$EMPTY" | sort) <(echo "$NUMBERS" |  sort)`

It works OK. Is there a bug or am I doing something wrong? I have dropped '-n', but I was just wondering if there is a good explanation for this.

Thanks.
Stephen

2

What is $EMPTY and $NUMBERS?
Do they hold filenames?

3

Variables containing the lists. $EMPTY is an empty string.