I want to be able to run expdp and impdp by directly specifying the connection parameters instead of a TNS name that resides in tnsnames.ora. Is this possible?
You may be able to specify it all on the command line with a Connection String instead of a TNSName. Remove the whitespace from your TNS entry you would have used to connect, here is an example that works with SQLPLUS...
Here is how to connect to a local OracleXE install on Windows:
sqlplus scott/tiger@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SID=xe)))
On *Nix you may need to quote the entry so the parens aren't interpreted incorrectly:
sqlplus 'scott/tiger@(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=localhost.localdomain)(PORT=1521)))(CONNECT_DATA=(SERVER=DEDICATED)(SID=xe)))'