echo "cs courses accounts\n"
ypcat passwd | awk -F: '/^cs[5-9][0-9]+/ {print $1,   $5 }'
echo "-------\n"
echo "faculty accounts: print login and name\n"
ypcat passwd | awk -F: '$4 == 13 {print $1  "--> " $5 }' 
echo "-------\n"
echo "faculty accounts: print all fields except the passwd\n"
ypcat passwd | awk -F: '$4 == 13 {$2="" ; {print}}'  
echo "-------\n"
echo "faculty accounts: print line number, loging and name\n"
ypcat passwd | awk -F: '$4 == 13 {print ++count ": "  $1  "--> " $5 }'