Steven D'Aprano wrote: > Open "the" file? There are potentially two files -- the source > and destination. I only want to do the rename if the > destination *doesn't* exist, so there is no destination file to > open. How will it help me to lock the source file? Have I > misunderstood?
I forgot to say, to open the source file with O_CREAT | O_EXCL. The open will fail if the file already exists. By locking the file no other process will be able to access it, but the process that holds the lock can do with it anything. This includes to rename an existing file to the name of the opened one - the previously created placeholder file will get unlinked before, but there is _probably_ no way that any process can intercept this. It is an interesting thing, that files that are opened remain fully usable and accessible if you unlink them as long you don't close them. You have to close it, to remove all remains of it. Wolfgang Draxinger -- E-Mail address works, Jabber: [EMAIL PROTECTED], ICQ: 134682867 GPG key FP: 2FC8 319E C7D7 1ADC 0408 65C6 05F5 A645 1FD3 BD3E -- http://mail.python.org/mailman/listinfo/python-list
