$ cat  examples/intro/names.txt
Foo 11
Bar 2
Moo 1

$ sort  examples/intro/names.txt
Bar 2
Foo 11
Moo 1

$ sort -k2 examples/intro/names.txt
Moo 1
Foo 11
Bar 2

$ sort -k2 -n examples/intro/names.txt
Moo 1
Bar 2
Foo 11

