On 15 March 2017 at 06:22, Chris Barker <chris.barker@noaa.gov> wrote:
So the question nis -- is anyone counting on errors in this case? i.e., is a sysadmin thinking:

"I want an ASCII-only system, so I'll set the locale, and now I can expect any program running on this system that is not ascii compatible to fail."

I honestly don't know if this is common -- but I would argue that trying to run a unicode-aware program on an ASCII-only system could be considered a mis-configuration as well.

From a mainstream Linux point of view, it's not common - on systemd-managed systems, for example, the only way to get the C locale these days is to either specify it in /etc/locale.conf, or to set it specifically in the environment. Upstart was a little less reliable about that, and sysvinit was less reliable still, but the trend is definitely towards making C.UTF-8 the assumed default, rather than "C". Even glibc itself would quite like to get to a point where you only get the C locale if you explicitly ask for it: https://sourceware.org/glibc/wiki/Proposals/C.UTF-8

The main practical objection that comes up in relation to "UTF-8 everywhere" isn't to do with UTF-8 per se, but rather with the size of the collation tables needed to do "proper" sorting of Unicode code points. However, there's a neat hack in the design of UTF-8 where sorting the encoded bytes by byte value is equivalent to sorting the decoded text by the Unicode code point values, which means that "LC_COLLATE=C" sorting by byte value, and "LC_COLLATE=C.UTF-8" sorting by "Unicode code point value" give the same results.

Cheers,
Nick.

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Nick Coghlan   |   ncoghlan@gmail.com   |   Brisbane, Australia