Think about that for a moment: how might that affect editors (like vim or emacs), Web pages and forms, databases, Perl itself, Perl IO, your Perl source code (if you want to include a character with a multi-byte encoding)? How might that affect passing strings around, if the strings contain characters with multi-byte encodings? Do regular expressions still work?Ĭharacter Encoding Comparison Character EncodingĪs you can see from the table above, codepoints 128-255 (0x80-0xff) are where you need to be careful. So, to reiterate, with UTF-8, not all characters are encoded into a single byte (unlike ASCII and ISO-8859-1). (If only ASCII characters are used, then they are all interchangeable, since ASCII, ISO-8859-1, and UTF-8 all share the same encoding for the first 128 Unicode codepoints.) Therefore, ISO-8859-1 and UTF-8 are not interchangeable. UTF-8 uses two bytes to encode each of these codepoints, whereas ISO-8859-1 only uses one byte for each character in that range. Note that although Unicode codepoints 128-255 are the same as ISO-8859-1, UTF-8 encodes each of these codepoints differently. Three or four bytes are needed to encode the remaining codepoints. The next 1,920 codepoints use two-byte encoding in UTF-8. These byte values are the same as US-ASCII, making UTF-8 encoding and ASCII encoding interchangeable if only ASCII characters are used. In UTF-8 encoding, the first 128 Unicode codepoints use one byte. You will probably want to use UTF-8, if you decide to use Unicode.Īn encoding defines how each Unicode codepoint maps to bits and bytes. Other encodings include UTF-7, UTF-16, UTF-32, etc. UTF-8 is a specific encoding of Unicode - the most popular encoding. Also, because of backward compatibility with legacy encodings, some characters have multiple codepoints. If you view the Unicode character reference, you will notice that not every codepoint has an assigned character. Use Unicode::UCD 'charinfo' use Data::Dumper print Dumper ( charinfo ( 0x263a )) # U+263a To view properties for a particular codepoint: The first 256 code points are the same as ISO-8859-1 to make it trivial to convert existing Western/Latin-1 text. Each character is assigned a unique codepoint, such as U+0030. Unicode is a standard that specifies all of the characters for most of the World's writing systems. See also Perl Unicode Cookbook - 44 recipes for working with Unicode in Perl 5. Unicode (usually in UTF-8 form) is replacing ASCII and the use of 8-bit "code pages" such as ISO-8859-1 and Windows-1252. Multiple languages can even be supported on the same Web page. In the context of application development, Unicode with UTF-8 encoding is the best way to support multiple languages in your application. 3.3 Encode module vs built-in/core utf8::. ![]()
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