On 2010-05-04, Cameron Simpson <c...@zip.com.au> wrote: > On 03May2010 15:23, Baz Walter <baz...@ftml.net> wrote:
>| so "here" must always be available somehow, even if getcwd() fails > > Well, yeah. Just like an open file handle on a file you have > subsequently removed still exists. Remember that the directory tree > is a digraph, and (historically at least, and probably for real in > many filesystems) '.' and '..' are just pointers to "here" and "up". > > Your rmdir has detached the current directory from the one that was > "up", but the "up" pointer still references the old parent. > > There's just no filesystem path that refers to your current directory > any more (except '.'). Just like a detached object in python really. Indeed. In fact, CPython uses a pointer/link and reference counting scheme that's pretty much identical to that used by Unix filesystems except that Python objects can form a generalized graph, and Unix filesystems are constrained to be a tree. Though once upon a time SunOS allowed you to create arbitrary graphs within a filesystem by allowing you to create hard links to directories. You had to be root, and you had to use some sort of override option on the command line (probably -f). If you knew enough to gracefully extract yourself from the situation, you probably wouldn't have done it in the first place. IOW, it wasn't something one did a second time. Still, at the time, it _seemed_ like a good way to share a directory of source code amongst multiple projects. I don't remember why symlinks wouldn't accomplish the task -- something to do with RCS... -- Grant -- http://mail.python.org/mailman/listinfo/python-list
