root:$1$yOVPpScN$MlmYppDEYfwMMuDnthdIj.:18100:0:99999:7:::Login name and / etc / passwd file name of the landing field corresponding
password encrypted
since the last days of the past to change the password password (since 1970.1.1 calculated)
number of days to change the password
must change the password number of days
before the password expires how many days in advance to remind the user to change the password
password expires after the number of days to disable a user account
user account is disabled date (from 1970.1.1 by the number of days to the day)
a reserved field for future use