Find Linux users that can log in with password

# www.fduran.com
# Check which Linux users could log in with password, see "man shadow" for the second field in the /etc/shadow file:
# "If the password field contains some string that is not a valid result of crypt(3), for instance ! or *, the user will not be able to use a unix password to log in (but the user may log in the system by other means).
# this awk one-liner will find users that have common used * or ! in the password field or field starts with ! (locked account). It's possible that still found user cannot log in due to other character

awk -F: '$2 != "*" && $2 !~ /^!/ { print $1, " can log in" }' /etc/shadow