$ ls -s | sort -n
96 Nov1.txt
128 _arch_backup.lst
128 _arch_backup.lst.tmp
1708 NMON
$ cat phonebook
Smith, Brett 555-4321
Doe, John 555-1234
Doe, Jane 555-3214
Avery, Cory 555-4321
Fogarty, Suzie 555-2314
$ sort phonebook
Avery, Cory 555-4321
Doe, Jane 555-3214
Doe, John 555-1234
Fogarty, Suzie 555-2314
Smith, Brett 555-4321
$ du /bin/* | sort -n
4 /bin/domainname
24 /bin/ls
102 /bin/sh
304 /bin/csh
$ cat zipcode
Adam 12345
Bob 34567
Joe 56789
Sam 45678
Wendy 23456
$ sort -nk 2 zipcode
Adam 12345
Wendy 23456
Bob 34567
Sam 45678
Joe 56789
$ sort -nrk 2 zipcode
Joe 56789
Sam 45678
Bob 34567
Wendy 23456
Adam 12345