It is possible to run the Oracle exp or imp (and probably other commands) without getting your tnsnames.ora and your environment variables 100% right.  (You will need them at least part-way right.) Here's how to run exp:

exp userid/password@sidname direct=y recordlength=65535 feedback=1000 file=test1.dmp log=test1.log tables=(TABLENAME)

Note: sidname might be globalname instead; I’m not sure.

SQL*Plus can be run without TNSNAMES by using

sqlplus userid/