> os.execv('ensight7.sos', 'ensight7.sos', '-c', 'somehost.somewhere.gov') > > That's it. I don't have control over how ensight7...... When I run > ensight7.sos -c somehost.somewhere.gov > from the command line, it works fine. Try launching a shell process that calls your program. -- Dennis Reinhardt DennisR at dair.com http://www.dair.com