PHP:
awk -F: '{ print $1 }' /etc*/passwd | sort
awk -F: '{ print $1 " "$2 " " $3" "$4" "$5 " "$6" "$7" "}' /etc*/passwd | sort
cd /etc;cat passwd
cat /etc/valiases/xxx.com
awk -F":" '{ print "user****: " $1 "\t\tuid:" $3 }' /etc/passwd
grep -v -E "^#" /etc/passwd | awk -F: '$3 == 0 { print $1}'