Sort and uniq format to thousand separator

Question

How to format line counts after sort and uniq add thousand separator

Sample Input:

1000 A
3000 B

Output:

1,000 A
3,000 B

Answer 1

Using numfmt from GNU Coreutils:

printf '1000 A\n3000 B\n' | numfmt --field=1 --grouping
1,000 A
3,000 B

The result that you get may depend on your locale.