Shell Programming and Scripting

for username in 'cat /etc/passwd | cut -d: -f1'
do
     # if $username ends in 1 echo $username is in group 1
     # else if $username ends in 2 echo $username is in group 2
     # else $username is in neither group
done

case $username in 
  *1) echo $username is in group 1 ;;
  *2) echo $username is in group 2 ;;
  *)  echo $username is in neither group ;;
esac

while read line
do
  username=${line%%:*}
  case $username in 
    *1) echo $username is in group 1 ;;
    *2) echo $username is in group 2 ;;
    *)  echo $username is in neither group ;;
   esac
done < /etc/passwd

awk -F: '$1 ~ /.*[1-2]$/ {print "Username " $1 " is in group ", substr($1,length($1))}' /etc/passwd

sed -n 's/\([^:]\([1-2]\)\):.*[1-2].*$/\1 is in group \2/p' /etc/passwd