[ruby-core:111349] [Ruby master Feature#19191] Implicit console input transcoding is more desirable

Issue #19191 has been updated by YO4 (Yoshinao Muramatsu).


I agree that the IRB issue should be corrected on the part of the IRB.

My point was that for certain devices, external_encoding on read can be fixed to the device's specification.
In that case, external_encoding is not used when internal_encoding is specified,
and if only external_encoding is specified, it is treated as a conversion from device_encoding to external_encoding.

Input from the console will be treated as locale encoding.

----------------------------------------
Feature #19191: Implicit console input transcoding is more desirable
https://bugs.ruby-lang.org/issues/19191#change-100723

* Author: YO4 (Yoshinao Muramatsu)
* Status: Open
* Priority: Normal
----------------------------------------
In response to Bug #18353, STDIN.internal_encoding are set and encoding is converted explcitly on Windows platform.
For example, ```[STDIN.external_encoding, STDIN.internal_encoding] # => [Encoding::Windows-31J, Encoding::UTF-8]``` if STDIN is console.

I feel that internal_encoding should be reserved for specific applications. And I think setting internal_encoding to STDIN is not foreseened.

Today I found irb breaks STDIN encoding, like

```
>ruby -rirb -e "p [$stdin.external_encoding, $stdin.internal_encoding]; IRB.setup(''); IRB::Irb.new(); p [$stdin.external_encoding, $stdin.internal_encoding]"
[#<Encoding:Windows-31J>, #<Encoding:UTF-8>]
[#<Encoding:UTF-8>, nil]
```

We know input has console code page encoding. So we always can convert encoding from console code page to io_input_encoding().

### proposal
when reading from console on Windows, input encoding is enfoced to console code page and encoding conversion is implicitly applied.

when ```set_encoding("UTF-8")``` implicitly converts console code page to UTF-8.
when ```set_encoding("CP437", "UTF-8")``` implicitly converts console code page to UTF-8. external_encoding is ignored.

binmode or binary input method is not affected by these specifications.
set_encoding, etc. will continue to work as before, and this specification will affect only when encoding conversion on read (NEED_READCONV() and make_readconv()).




-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- [e-mail]
 To unsubscribe send an email to [e-mail]
 ruby-core info -- https://ml.ruby-lang.org/mailman3/postorius/lists/ruby-core.ml.ruby-lang.org/