ruby-script-encoding

ref: https://ruby-doc.org/core-3.0.0/Encoding.html#class-Encoding-label-Script+encoding

终于知道了ruby script里encoding这个magic comment是什么作用了

这个magic comment不是被编辑器解析的, 而是由ruby解释器解析的(not 100% sure)

All Ruby script code has an associated Encoding which any String literal created in the source code will be associated to.

The default script encoding is Encoding::UTF_8 after v2.0, but it can be changed by a magic comment on the first line of the source code file (or second line, if there is a shebang line on the first).
The comment must contain the word coding or encoding, followed by a colon, space and the Encoding name or alias:

The __ENCODING__ keyword returns the script encoding of the file which the keyword is written:

  • file1.rb

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    # encoding: ASCII-8BIT

    p "hello".encoding # #<Encoding:ASCII-8BIT>
    p __ENCODING__ # #<Encoding:ASCII-8BIT>

  • file2.rb

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    # encoding: UTF-8

    p "hello".encoding # #<Encoding:UTF-8>
    p __ENCODING__ # #<Encoding:UTF-8>