Specifying Program Encoding in Ruby

Types of Encoding:

There are various encoding schemes such as ASCII, UTF-8, UTF-16, Hex, Base64, SJIS, etc. Multiple encoding techniques allow for the incorporation of different languages worldwide. The two famous encoding techniques are discussed below:

• ASCII: It is a macro for American Standard Code for Information Interchange. This is a character encoding standard for digital communication. ASCII codes represent text in computers, communications equipment, and other electronic devices.

ASCII TABLE

• UTF-8: It is a variable byte character encoding standard used for digital communication. The name comes from “Unicode Transformation Format - 8-bit”, defined by Unicode Standard. UTF-8 can encode all 1.112.064 valid character code points. It uses one to four one-byte code units. UTF-8 encoded files are identified if the first three bytes of files are 0xEF 0xBB 0xBF. These bytes are the BOM or “Byte Order Mark” optional in UTF-8-encoded files. 

Specifying program encoding in Ruby

• Ruby interpreter, by default, assumes that programs are encoded in ASCII.
• You may specify a different encoding with the -K command-line option.
• To use UTF-8 encoding in Ruby programs, use the -Ku command.
• -Ke and -Ks options are used to run EUC-JP or SJIS encodings.
• In Ruby 1.9, the script’s author can specify the encoding by using a particular ‘coding comment’ at the beginning of the file. 

For example: # coding: utf-8

• From Ruby 1.9, users don’t have to specify the encoding. It's done from the developer's side.
• The coding comment must be strictly written in ASCII and include the string coding. This must be followed by a colon or equal sign and the name of the desired encoding.
• The coding comment is not case sensitive and can be written in upper or lower case.
• Encoding comments are usually only valid on the first line of the file. Ruby scans for a comment on the first or second line that contains the string ‘encoding’.
• If the first line is a shebang comment, the encoding comment shifts to the second line.

Example: #!/usr/bin/ruby -w 

    # coding: utf-8

• Ruby also supports source encodings such as ASCII-8BIT, US-ASCII, ISO-8859-1, SJIS and EUC-JP.
•  The language keyword __ENCODING__ evaluates the source encoding of the currently executing code.

Frequently Asked Questions

What is the advantage of using Ruby?

It is secure, flexible, and open-source with native multi-threading support.

What is an interpreter?

Interpreters are computer programs that allow direct execution of code or script without the need for compilation first.

What is a shebang comment in Ruby?

This comment makes the Ruby script executable on Unix-like operating systems.

What is a scripting language?

It is a language for run-time systems that automates the execution of tasks.

How many characters are listed in ASCII encoding?

ASCII is a 7-bit character set that contains 128 characters

Conclusion

In this blog, you learned about specifying program encoding, encoding in general, and encoding types. The knowledge gained here will help you write Ruby scripts that will run in various languages.

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