if-then
if command
then
command
fi
if-then-else
if command
then
command
else
command
fi
Nested if
if command
then
command
elif command
then
command
elif command
then
command
else
command
fi
if command
then
command
fi
if command
then
command
else
command
fi
if command
then
command
elif command
then
command
elif command
then
command
else
command
fi