> -----Original Message----- > From: dn <pythonl...@danceswithmice.info> > Sent: Saturday, April 23, 2022 6:05 PM > To: python-list@python.org > Subject: Re: tail > <Snipped> > NB quite a few of IBM's (extensively researched) algorithms which formed > utility > program[me]s on mainframes, made similar such algorithmic choices, in the > pursuit of efficiencies.
WRT the mentioned IBM utility program[me]s, the non-Posix part of the IBM mainframe file system has always provided record-managed storage since the late 1960's (as opposed to the byte-managed storage of *ix systems) so searching for line endings was (and is) irrelevant and unnecessary in that environment. That operating system also provides basic "kernel-level" read-backwards API's for the record-managed file system, so there was never any need to build reverse-read into your code for that environment. The byte-managed file storage used by the Posix kernel running under the actually-in-charge IBM mainframe operating system is, of course, subject to the same constraints and (in)efficiencies discussed in this thread. Peter -- -- https://mail.python.org/mailman/listinfo/python-list
