Feature #22244: `ruby -UU` should set both internal and external, `ruby -E` should print encoding list

• Status: Open
• Assignee: -
• Target version: -

[zenspider (Ryan Davis)]

10004 $ env -u LANG ruby -U -e 'pp [Encoding.default_internal, Encoding.default_external]'
[#<Encoding:UTF-8>, #<Encoding:US-ASCII>]

10005 $ env -u LANG ruby -EUTF-8 -e 'pp [...]'
[nil, #<Encoding:UTF-8>]

10006 $ env -u LANG ruby -EUTF-8 -U -e 'pp [...]'
[#<Encoding:UTF-8>, #<Encoding:UTF-8>]

10007 $ env -u LANG ruby -EUTF-8:UTF-8 -e 'pp [...]'
[#<Encoding:UTF-8>, #<Encoding:UTF-8>]

10008 $ env -u LANG ruby -UU -e 'pp [...]'
[#<Encoding:UTF-8>, #<Encoding:US-ASCII>]

I think the option processing of encodings is VERY poorly documented and frustrating to try to use.

1. --help doesn't list -U. (The man page does)
2. --help for -E doesn't provide a means to get a list of available encoding names (same with manpage), leading me to try U, UTF8, UTF_8, before finding UTF-8. ruby -E could just print them all out.
3. WHY NOT take UTF8 or UTF_8 (since that's the class name)?
4. Please consider -UU to mean -EUTF-8:UTF-8

[zenspider (Ryan Davis)]

Quick and dirty patch: https://github.com/ruby/ruby/compare/master...zenspider:ruby:zenspider__encodings?expand=1

This is rough. I'm faking an eval early in the option handling. There is probably a better C way to do this. It is probably failing tests.

But the idea is there.

[zenspider (Ryan Davis)]

PR is being worked down with feedback from @nobu (Nobuyoshi Nakada)

https://github.com/ruby/ruby/pull/18319

:heart: