Using Bash shell you may use the following construct:

{

echo "DROP VIEW v1;"

echo "CREATE VIEW..."

} | isql -user SYSDBA -pass masterkey srv:db

each echo statement outputs newline at the end.

Because that's a lot of writing, use the so called 'document here' feature of the shell:

cat <<- _END_ | isql user SYSDBA -pass masterkey srv:db

DROP VIEW v1;

CREATE VIEW ...

...

_END_