Feature #19718: Extend `-0` option

• Status: Rejected
• Assignee: -
• Target version: -

[nobu (Nobuyoshi Nakada)]

Recently I learned that Perl's -0 option is extended to accept a hexadecimal Unicode codepoint.
However it uses -0x, and since -x is used for shebang and cd, it would cause a backward incompatibility if we will incorporate it as it is.

So I propose that -0uCODEPOINT instead.
This can be extended to comma- or colon-separated codepoint list.

Also, another idea is -0:sepaerator which specifies the separator as-is.
Considering many of modern shells provide escaped string form (e.g., `$'\uHHHH'), this may be a more modern answer, except for NUL cannot be represented.

https://github.com/ruby/ruby/pull/7914

[Dan0042 (Daniel DeLorme)]

It's a nifty idea, but -0uCODEPOINT means that the -u option is forever reserved for this usage which no one will ever really use I think, because -0 is meant to be used like xargs -0 option (ex: find . -print0 | ruby -0ne 'p $_.chomp') and I can't imagine why anyone would use anything other than NUL. Although I would love to be shown wrong.
-0:separator doesn't have that downside.

[nobu (Nobuyoshi Nakada)]

I thought the issue about -u is simply a matter of priorities; just the chance of -0x cannot be denied, but -0u should have never been used.

But now I remembered -U has been implemented since 1.9.
My patch allows -0U as well as -0u, and would need to change.
Probably a punctuation (like as :) may be possible.

[Dan0042 (Daniel DeLorme)]

I meant it will not be possible to use -u in the future.
With colon we could write anything after, like -0:$'\t' or -0:011 or -0:x09 or -0:u0009 or -0:b1001 😃
Or use = instead of : ?
Cheers.

[nobu (Nobuyoshi Nakada)]

Dan0042 (Daniel DeLorme) wrote in #note-3:

I meant it will not be possible to use -u in the future.

Yes, and I thought it wouldn’t be a problem, but might not be a good idea.

With colon we could write anything after, like -0:$'\t' or -0:011 or -0:x09 or -0:u0009 or -0:b1001 😃
Or use = instead of : ?

-0=$'\t' and -0:09(= -0:x09)?

[matz (Yukihiro Matsumoto)]

• Status changed from Open to Rejected

Very few users know the existence of -0. If we extend the option, probably no one uses the feature.

Matz.