[EMAIL PROTECTED] wrote: > Hi, > > there are many ways of solving the problem of finite buffer sizes when > talking to a subprocess. I'd usually suggest using select() but today I > was looking for a more readable/understandable way of doing this. Back > in 1997 Guido himself posted a very nice solution, write your input to > a temporary file and then read that from your new process. His posting > can be found here: > http://groups.google.com/group/comp.lang.python/tree/browse_frm/thread/2b31d990a8613d93/17d3dea9089aad00?rnum=1&q=subprocess+deadlock&_done=%2Fgroup%2Fcomp.lang.python%2Fbrowse_frm%2Fthread%2F2b31d990a8613d93%2F63b0a786d87ba23b%3Flnk%3Dgst%26q%3Dsubprocess+deadlock%26rnum%3D6%26#doc_63b0a786d87ba23b > > Being a bit puzzled over this usage of tempfile I read its > documentation and as expected it says: > > [...] The file is created using mkstemp. It will be destroyed as soon > as it is closed (including an implicit close when the object is garbage > collected). [...] your code should not rely on a temporary file created > using this function having or not having a visible name in the file > system. > > so how was Guido planning to get the contents of the file after closing > it? Should we do a tf.flush() instead of the close to ensure everything > is written, then read from it, using subprocess.Popen(....,stdin=tf,..) > and only close it afterwards? > > Is it correct to assume that a named temporary file will be (sometimes) > accesible while it has not been closed yet? > > cheers, > tim
When GvR wrote that around a decade ago, tempfile.mktemp() had not yet been deprecated. It returns "an absolute pathname of a file that did not exist at the time the call is made". It does not create a file, you have to do that yourself. You're quoting the docs for tempfile.TemporaryFile(). It returns a "file (or file-like) object", and I'd assume that you would have to pass this object around without closing it in order to use it in the manner described in GvR's post. http://docs.python.org/lib/module-tempfile.html -- http://mail.python.org/mailman/listinfo/python-list
