base85

Stream encoder and decoder of base85 as used in e.g. Mercurial. Run with “-h”
for synopsis. base85 reads from stdin and writes to stdout. Default operation is
encoding, swithch to decoding with the “-d” flag.

base64.b85encode

Python's base85 API works on bytes-like objects. By chunking the input and
output streams, base85 avoids having to keep the entire file in memory. The
resulting streams are identical to encoding or decoding an entire file in one
invokation, though, as the program would be quite useless otherwise.

PyPy

Running the program with PyPy instead of CPython showed a large increase in
throughput on my system, so the runtime invoked by the hashbang is pypy3.
Changing it to python3 should obviously have no other effects than lower
throughput on large files.

forcedeol

base85 does not prettyprint its output. forcedeol is a small utility which
blindly enforces no more than 80 octets between each newline character. Compile
with something like::

    gcc -Wall -O2 -oforcedeol forcedeol.c

Licence

Copyright 2019, 2020 Steinar Knutsen

Licensed under the EUPL, Version 1.2 or – as soon they will be approved by the
European Commission – subsequent versions of the EUPL (the “Licence”); You may
not use this work except in compliance with the Licence. You may obtain a copy
of the Licence at:

https://joinup.ec.europa.eu/collection/eupl/eupl-text-eupl-12

Unless required by applicable law or agreed to in writing, software distributed
under the Licence is distributed on an “AS IS” basis, WITHOUT WARRANTIES OR
CONDITIONS OF ANY KIND, either express or implied. See the Licence for the
specific language governing permissions and limitations under the Licence.