Extract dates from /etc/shadow

Question

The file /etc/shadow has a couple date fields that are expressed as the number of days since Jan 1, 1970. Is there an easy way using to get a list of users and the calendar date of the last password change, and the expiration?

Ref: man shadow(5)

Answer 1

There was an answer that got deleted, while somewhat wrong, did lead me in the correct direction.

Using gawk's strftime combined with some arithmetic gives me what I wanted.

cat shadow | gawk -F: '{ print $1 ":" strftime("%Y%m%d",86400*$3) ":" strftime("%Y%m%d",86400*$4)}'

root:20120304:19691231
daemon:20100203:19691231
bin:20100203:19691231
sys:20100203:19691231

Answer 2

report password status on the named account passwd -S username

for user in $(cut -d: -f1 /etc/passwd); do sudo passwd -S $user; done

Answer 3

for n in $(sudo cat /etc/shadow | awk '{FS=":";print $3}'); do date -d "01/01/1970 +${n}days" +%F; done