Unix processes want an additional "argument 0" which by default is the name of the program file.
I found that out, however, heres a puzzle then: I am doing exactly the same thing while unzipping uploaded files.... ie in the code replace '/usr/bin/zip' with '/usr/bin/unzip' and hte args and the other stuff... and that seems to work everytime. If agree about the argv[0] thingy, however then my unzipping shouldnt work either. Re: Dennis' solution of using os.system, the docs say if I do a system it replaces the calling thread (I dont yet understand the meaning of replace in this context) and only resumes after returning. In a web server environ wouldnt that be dangerous as it might replace Zope's calling thread even if for some time. I confess I dont know how exactly the calling mechaninsm for external methods work, but if I was right I would have a sequential process which would be bad for a web-site I think. Re:Chris, I will try popen adn Zipfile again. Thanks all. AM