On Tue, Jan 31, 2017 at 12:58 AM, Peter Otten <__pete...@web.de> wrote: >> I looked at help(os.link) on Python >> 3.4 and the corresponding current library documentation on the web. I >> saw no mention of what happens when dst exists already. >> >> Also, creating a hard link doesn't seem to work between different file >> systems, which may well be relevant to Steve's case. > > In his example above he operates inside a single directory. Can one > directory spread across multiple file systems?
Yep. Try unionfs. ... make ourselves some scratch space ... $ mkdir space modifier $ dd if=/dev/zero of=space.img bs=4096 count=65536 $ mkfs space.img $ sudo mount space.img space $ dd if=/dev/zero of=modifier.img bs=4096 count=1024\ $ mkfs modifier.img $ sudo mount modifier.img modifier ... put some content into the base directory ... $ sudo -e space/demo.txt ... and now the magic: $ unionfs modifier=RW:space=RO joiner/ $ cd joiner At this point, you're in a directory that is the union of the two directories. One of them is read-only, the other is read/write. It is thus possible to view a file that you can't hard-link to a new name, because the new name would have to be created in the 'modifier' file system, but the old file exists on the 'space' one. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
