did you try
sqlplus username/password@host:port/service
sqlplus x/y@c:a/b
modern versions of sqlplus (version 11 or newer) understand this syntax and you don't need a tnsnames.ora file.
did you try
sqlplus username/password@host:port/service
sqlplus x/y@c:a/b
modern versions of sqlplus (version 11 or newer) understand this syntax and you don't need a tnsnames.ora file.