Shell Programming and Scripting

echo -n "Username "
stty -echo
read username
stty echo
echo ""         # force a carriage return to be output
echo You entered $username
correct = "$( cat /root/file cut -d: f1)"
if [ $username = $correct ] ; then 
echo -e "username is correct"
else 
echo -e "username is wrong"
fi
echo -n "Password: "
stty -echo
read password
stty echo
echo ""         # force a carriage return to be output
echo You entered $password
correct = "$( cat /root/file cut -d: f2)"
if [ $password = $correct ] ; then 
echo -e "passsword is correct"
else 
echo -e "password is wrong"
fi

username is coorect
password is correct..

if [ $a == 5 ] || ( [ $a == 4 ] && [ $b == 5 ] )

if [ "$a" == 5  -o "$a" == 4 -a "$b" == 5 ]

if [ "$a" -eq "5" ] || [ "$a" -eq "4" -a "$b" -eq "5" ]

if (( $a == 5 || ( $a == 4 && $b == 5 ) ))