[Tutor] Through a glass, darkly: the datetime module
eryksun at gmail.com
Mon Oct 8 04:33:08 CEST 2012
On Sat, Oct 6, 2012 at 11:56 PM, Steven D'Aprano <steve at pearwood.info> wrote:
> The C programming language on Unix systems.
> "ls" instead of "list"
"LS" is an abbreviation for "list segments", not "list". It goes back
to Multics in the late 60s and 70s. In Multics, every segment is a
file, and every file is a segment (basically a memory mapped file with
an 18-bit address space, and using 36-bit words -- or 1.125 MiB) or a
28-bit, page-aligned 'windowed' segment -- or so I've read. It was
quite an odd system compared to what I'm used to. But it was also
fairly modern for a system developed in the late 60s -- it had hot
swappable processors/peripherals, paged virtual memory, dynamic
linking of segments/files into a process by symbolic (file system)
pathname, process security rings (e.g. ring 0 for privileged
supervisor code), directories and symbolic links in the file/segment
tree, user access control lists, and who knows what else (I'm still
reading a lot of the old papers available at multicians.org).
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