Non-standard Ascii Character Changed To Unicode In ANSI File #52642

UTF-16 is also variable length character encoding but either takes 2 or 4 bytes. On the other hand UTF-32 is fixed 4 bytes. UTF-8 has an advantage where ASCII are most used characters, in that case most characters only need one byte. UTF-8 file containing only ASCII characters has the same...Handling special characters in C(UTF-8 encoding) (3). I'm writing a small application in C that reads a simple text file and then outputs the lines one by one. Remember that the width of a code-point or character in UTF-8 is variable. This means you can't just seek to a byte and begin reading like with...The replacement encoding, listed in the Encoding specification, is not actually an encoding; it is a fallback that maps every octet to the Unicode code The x-user-defined encoding is a single-byte encoding whose lower half is ASCII and whose upper half is mapped into the Unicode Private Use...Their goal is to replace the existing character sets with its standard Unicode Transformation Format (UTF). The Unicode standard is also supported in many operating systems and all modern browsers. UTF-8 is backwards compatible with ASCII. UTF-8 is the preferred encoding for e-mail...The Unicode standard defines code points (numbers) for each of the characters it defines. UTF-8 is a variable length encoding that is compatible with ASCII in those important senses. That doesn't mean that all UTF-8 characters are ASCII characters, or even that string processing libraries are equipped...

used - why did utf-8 replace ascii character encoding standard

UTF-8 is a variable-width character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from Unicode (or Universal Coded Character Set)...Unicode simply uses all character codes in ASCII and adds more. Although character codes are UTF-8 is not a character set but an encoding used with Unicode. It happens to be compatible with ASCII too, because the codes used for multiple byte encodings lie in the part of the ASCII character...Unicode-based encodings implement the Unicode standard and include UTF-8, UTF-16 andreplacing UTF-8 with whatever your embedded encoding is. This code must come before any This character encoding will then be set for any file directly in or in the subdirectories of directory you...UTF-8 supports any unicode character, which pragmatically means any natural language (Coptic, Sinhala, Phonecian, Cherokee etc), as well as many non-spoken languages (Music notation Typically a character set corresponds to a language family, but the correspondence is not exactly one-to-one.

Choosing & applying a character encoding | Why use UTF-8?

We will assume the standard definition of ASCII that is limited to 128 characters (namely, byte values whose most significant bit is 0). Unicode was designed Note that this method is not entirely safe. If there exists a multi-byte encoding that does fancy mappings of consecutive bytes or characters...ASCII - American Standard Code for Information Interchange. Character encoding is the American Standard Code for Information Interchange, and is the US precursor to ISO 646 ASCII is still widely used today, even though UTF-8 has become more important when presenting a text.Both ASCII UTF-8 are used for encoding characters in computer communication. UTF-8 was favored over ASCII because it provided more characters than is available in ASCII making it more acceptable world over.1 point ASCII can store a character in more than one byte. UTF-8 only uses 128 values. Why join Brainly? ask questions about your assignment. get answers with explanations.But how do we represent these characters in memory? Enter, the grand daddy of character sets, ASCII (yes, we Since the ASCII only incorporated English letters, many people had the same idea to incorporate their own UTF-8 is an encoding system used for storing the unicode Code Points, like...

Jump to navigation Jump to go looking UTF-8StandardUnicode StandardClassificationUnicode Transformation Format, prolonged ASCII, variable-width encodingExtendsUS-ASCIITransforms / EncodesISO 10646 (Unicode)Preceded byUTF-1vte

UTF-8 is a variable-width personality encoding used for electronic conversation. Defined by way of the Unicode Standard, the identify is derived from Unicode (or Universal Coded Character Set) Transformation Format – 8-bit.[1]

UTF-Eight is able to encoding all 1,112,064[nb 1] legitimate character code points in Unicode using one to 4 one-byte (8-bit) code gadgets. Code points with lower numerical values, which have a tendency to occur extra often, are encoded using fewer bytes. It was designed for backward compatibility with ASCII: the first 128 characters of Unicode, which correspond one-to-one with ASCII, are encoded using a unmarried byte with the same binary value as ASCII, in order that valid ASCII text is legitimate UTF-8-encoded Unicode as properly. Since ASCII bytes don't happen when encoding non-ASCII code issues into UTF-8, UTF-Eight is safe to use inside of most programming and document languages that interpret certain ASCII characters in a special method, equivalent to / (slash) in filenames, \ (backslash) in break out sequences, and % in printf.

UTF-8 was designed as a superior alternative to UTF-1, a proposed variable-width encoding with partial ASCII compatibility which lacked some options including self-synchronization and entirely ASCII-compatible handling of characters comparable to slashes. Ken Thompson and Rob Pike produced the first implementation for the Plan 9 running system in September 1992.[2][3] This ended in its adoption via X/Open as its specification for FSS-UTF, which might first be officially introduced at USENIX in January 1993 and subsequently adopted through the Internet Engineering Task Force (IETF) in RFC 2277 (BCP 18) for long run Internet standards paintings, replacing Single Byte Character Sets equivalent to Latin-1 in older RFCs.

UTF-Eight is by way of some distance the most commonplace encoding for the World Wide Web, accounting for 97% of all internet pages, and as much as 100% for some languages, as of 2021.[4]

Naming

The reputable Internet Assigned Numbers Authority (IANA) code for the encoding is "UTF-8".[5] All letters are upper-case, and the name is hyphenated. This spelling is utilized in all the Unicode Consortium paperwork in terms of the encoding.

Alternatively, the identify "utf-8" could also be used by all standards conforming to the IANA checklist (which come with CSS, HTML, XML, and HTTP headers),[6] as the declaration is case insensitive.[5]

Other variants, similar to those that omit the hyphen or replace it with an area, i.e. "utf8" or "UTF 8", aren't approved as proper by way of the governing standards.[7] Despite this, most internet browsers can understand them, and so criteria supposed to describe current observe (corresponding to HTML5) would possibly effectively require their recognition.[8]

Unofficially, UTF-8-BOM and UTF-8-NOBOM are every now and then used for textual content information which comprise or don't include a byte order mark (BOM), respectively. In Japan particularly, UTF-Eight encoding and not using a BOM is often referred to as "UTF-8N".[9][10]

Windows 7 and later, i.e. all supported Windows versions, have codepage 65001, as a synonym for UTF-8 (with better support than in older Windows),[11] and Microsoft has a script for Windows 10, to permit it by way of default for its program Microsoft Notepad.[12]

In PCL, UTF-Eight is known as Symbol-ID "18N" (PCL supports 183 persona encodings, referred to as Symbol Sets, which probably might be lowered to one, 18N, that is UTF-8).[13]

Encoding

Since the restriction of the Unicode code-space to 21-bit values in 2003, UTF-8 is explained to encode code points in a single to 4 bytes, depending on the selection of important bits in the numerical value of the code point. The following table displays the construction of the encoding. The x characters are replaced through the bits of the code level.

Code level <-> UTF-Eight conversion First code point Last code point Byte 1 Byte 2 Byte 3 Byte 4 U+0000 U+007F 0xxxxxxx U+0080 U+07FF 110xxxxx 10xxxxxx U+0800 U+FFFF 1110xxxx 10xxxxxx 10xxxxxx U+10000 [nb 2]U+10FFFF 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx

The first 128 characters (US-ASCII) need one byte. The next 1,920 characters need two bytes to encode, which covers the remainder of nearly all Latin-script alphabets, and also Greek, Cyrillic, Coptic, Armenian, Hebrew, Arabic, Syriac, Thaana and N'Ko alphabets, as well as Combining Diacritical Marks. Three bytes are needed for characters in the remainder of the Basic Multilingual Plane, which contains virtually all characters in not unusual use,[14] including most Chinese, Japanese and Korean characters. Four bytes are wanted for characters in the different planes of Unicode, which include much less commonplace CJK characters, more than a few ancient scripts, mathematical symbols, and emoji (pictographic symbols).

A "character" can in truth take greater than Four bytes, e.g. an emoji flag persona takes Eight bytes since it's "constructed from a pair of Unicode scalar values".[15] Byte-count can pass as much as no less than 17 for valid sets of combining characters.[16]

Examples

Consider the encoding of the Euro sign, €:

The Unicode code point for "€" is U+20AC. As this code point lies between U+0800 and U+FFFF, this will likely take 3 bytes to encode. Hexadecimal 20AC is binary 0010 0000 1010 1100. The two main zeros are added as a result of a three-byte encoding needs precisely sixteen bits from the code level. Because the encoding can be 3 bytes long, its leading byte begins with 3 1s, then a nil (1110...) The four most vital bits of the code level are stored in the last low order four bits of this byte (11100010), leaving 12 bits of the code point but to be encoded (...0000 1010 1100). All continuation bytes comprise precisely six bits from the code level. So the subsequent six bits of the code level are stored in the low order six bits of the next byte, and 10 is saved in the excessive order two bits to mark it as a continuation byte (so 10000010). Finally the ultimate six bits of the code point are saved in the low order six bits of the final byte, and again 10 is stored in the high order two bits (10101100).

The three bytes 11100010 10000010 10101100 can also be extra concisely written in hexadecimal, as E2 Eighty two AC.

The following table summarises this conversion, in addition to others with different lengths in UTF-8. The colours point out how bits from the code level are disbursed amongst the UTF-Eight bytes. Additional bits added via the UTF-8 encoding process are proven in black.

Examples of UTF-Eight encoding Character Binary code point Binary UTF-8 Hex UTF-8 $ U+0024 010 0100 00100100 24 ¢ U+00A2 000 1010 0010 11000010 10100010 C2 A2 ह U+0939 0000 1001 0011 1001 11100000 10100100 10111001 E0 A4 B9 € U+20AC 0010 0000 1010 1100 11100010 10000010 10101100 E2 Eighty two AC 한 U+D55C 1101 0101 0101 1100 11101101 10010101 10011100 ED Ninety five 9C 𐍈 U+10348 Zero 0001 0000 0011 0100 1000 11110000 10010000 10001101 10001000 F0 ninety 8D 88 Octal

UTF-8's use of six bits in step with byte to constitute the actual characters being encoded, implies that octal notation (which makes use of 3-bit teams) can support in the comparability of UTF-Eight sequences with one any other and in handbook conversion.[17]

Octal code level <-> Octal UTF-8 conversion First code point Last code level Byte 1 Byte 2 Byte 3 Byte 4 0 177 xxx 200 3777 3xx 2xx 4000 77777 34x 2xx 2xx 100000 177777 35x 2xx 2xx 200000 4177777 36x 2xx 2xx 2xx

With octal notation, the arbitrary octal digits, marked with x in the table, will stay unchanged when converting to or from UTF-8.

Example: € = U+20AC = 02 02 54 is encoded as 342 202 254 in UTF-8 (E2 Eighty two AC in hex).Codepage structure

The following desk summarizes usage of UTF-8 code units (person bytes or octets) in a code page format. The upper half (0_ to 7_) is for bytes used solely in single-byte codes, so it looks like an ordinary code web page; the decrease part is for continuation bytes (8_ to B_) and leading bytes (C_ to F_), and is defined additional in the legend beneath.

UTF-8 _0 _1 _2 _3 _4 _5 _6 _7 _8 _9 _A _B _C _D _E _F (1 byte)0_ .mw-parser-output span.smallcapsfont-variant:small-caps.mw-parser-output span.smallcaps-smallerfont-size:85%NUL0000 SOH0001 STX0002 ETX0003 EOT0004 ENQ0005 ACK0006 BEL0007 BS0008 HT0009 LF000A VT000B FF000C CR000D SO000E SI000F (1)1_ DLE0010 DC10011 DC20012 DC30013 DC40014 NAK0015 SYN0016 ETB0017 CAN0018 EM0019 SUB001A ESC001B FS001C GS001D RS001E US001F (1)2_ SP0020 !0021 "0022 #0023 [scrape_url:1]

{title}

{content}

[/scrape_url]24 %0025 &0026 '0027 (0028 )0029 *002A +002B ,002C -002D .002E /002F (1)3_ 00030 10031 20032 30033 40034 50035 60036 70037 80038 90039 :003A ;003B <003C =003D >003E ?003F (1)4_ @0040 A0041 B0042 C0043 D0044 E0045 F0046 G0047 H0048 I0049 J004A K004B L004C M004D N004E O004F (1)5_ P0050 Q0051 R0052 S0053 T0054 U0055 V0056 W0057 X0058 Y0059 Z005A [005B [scrape_url:1]

{title}

{content}

[/scrape_url]5C ]005D ^005E _005F (1)6_ `0060 a0061 b0062 c0063 d0064 e0065 f0066 g0067 h0068 i0069 j006A k006B l006C m006D n006E o006F (1)7_ p0070 q0071 r0072 s0073 t0074 u0075 v0076 w0077 x0078 y0079 z007A 007B 007D ~007E DEL007F 8_ •+00 •+01 •+02 •+03 •+04 •+05 •+06 •+07 •+08 •+09 •+0A •+0B •+0C •+0D •+0E •+0F 9_ •+10 •+11 •+12 •+13 •+14 •+15 •+16 •+17 •+18 •+19 •+1A •+1B •+1C •+1D •+1E •+1F A_ •+20 •+21 •+22 •+23 •+24 •+25 •+26 •+27 •+28 •+29 •+2A •+2B •+2C •+2D •+2E •+2F B_ •+30 •+31 •+32 •+33 •+34 •+35 •+36 •+37 •+38 •+39 •+3A •+3B •+3C •+3-d •+3E •+3F (2)C_ 20000 20040 Latin0080 Latin00C0 Latin0100 Latin0140 Latin0180 Latin01C0 Latin0200 IPA0240 IPA0280 IPA02C0 accents0300 accents0340 Greek0380 Greek03C0 (2)D_ Cyril0400 Cyril0440 Cyril0480 Cyril04C0 Cyril0500 Armeni0540 Hebrew0580 Hebrew05C0 Arabic0600 Arabic0640 Arabic0680 Arabic06C0 Syriac0700 Arabic0740 Thaana0780 N'Ko07C0 (3)E_ Indic0800 Misc.1000 Symbol2000 Kana…3000 CJK4000 CJK5000 CJK6000 CJK7000 CJK8000 CJK9000 AsianA000 HangulB000 HangulC000 HangulD000 PUAE000 FormsF000 (4)F_ SMP…10000 񀀀40000 򀀀80000 SSP…C0000 SPU…100000 4140000 4180000 41C0000 5200000 51000000 52000000 53000000 64000000 640000000

  Blue cells are 7-bit (single-byte) sequences. They will have to now not be followed through a continuation byte.[18]

  Orange cells with a large dot are a continuation byte.[19] The hexadecimal quantity shown after the + image is the worth of the 6 bits they add. This character never happens as the first byte of a multi-byte sequence.

  White cells are the leading bytes for a chain of a couple of bytes,[20] the length proven at the left fringe of the row. The textual content shows the Unicode blocks encoded via sequences beginning with this byte, and the hexadecimal code point proven in the cell is the lowest persona worth encoded using that leading byte.

  Red cells will have to never appear in a valid UTF-8 collection. The first two purple cells (C0 and C1) may well be used just for a 2-byte encoding of a 7-bit ASCII persona which will have to be encoded in 1 byte; as described underneath, such "overlong" sequences are disallowed.[21] To perceive why that is, believe the character 128, hex 80, binary One thousand 0000. To encode it as 2 characters, the low six bits are saved in the 2d character as 128 itself 10 000000, but the higher two bits are stored in the first character as 110 00010, making the minimal first personality C2. The pink cells in the F_ row (F5 to FD) point out main bytes of 4-byte or longer sequences that can't be valid as a result of they'd encode code points larger than the U+10FFFF prohibit of Unicode (a limit derived from the most code level encodable in UTF-16 [22]). FE and FF don't fit any allowed character development and are subsequently now not valid get started bytes.[23]

  Pink cells are the main bytes for a sequence of multiple bytes, of which some, but now not all, possible continuation sequences are valid. E0 and F0 may get started overlong encodings, on this case the lowest non-overlong-encoded code point is proven. F4 can start code issues greater than U+10FFFF that are invalid. ED can start the encoding of a code level in the range U+D800–U+DFFF; these are invalid since they're reserved for UTF-16 surrogate halves.[24]

Overlong encodings

In concept, it would be conceivable to inflate the number of bytes in an encoding via padding the code point with leading 0s. To encode the Euro sign € from the above instance in four bytes as a substitute of three, it might be padded with main 0s till it was once 21 bits lengthy – 000 000010 000010 101100, and encoded as 11110000 10000010 10000010 10101100 (or F0 82 Eighty two AC in hexadecimal). This is known as an overlong encoding.

The standard specifies that the right kind encoding of a code level uses solely the minimum collection of bytes required to hold the significant bits of the code point. Longer encodings are referred to as overlong and don't seem to be valid UTF-Eight representations of the code point. This rule maintains a one-to-one correspondence between code issues and their legitimate encodings, so that there's a distinctive legitimate encoding for every code level. This ensures that string comparisons and searches are well-defined.

Invalid sequences and blunder dealing with

Not all sequences of bytes are valid UTF-8. A UTF-Eight decoder should be prepared for:

invalid bytes an sudden continuation byte a non-continuation byte sooner than the end of the personality the string finishing earlier than the finish of the character (which will happen in easy string truncation) an overlong encoding a series that decodes to an invalid code point

Many of the first UTF-Eight decoders would decode these, ignoring flawed bits and accepting overlong results. Carefully crafted invalid UTF-Eight could lead them to both skip or create ASCII characters equivalent to NUL, slash, or quotes. Invalid UTF-Eight has been used to avoid security validations in high-profile merchandise together with Microsoft's IIS web server[25] and Apache's Tomcat servlet container.[26]RFC 3629 states "Implementations of the decoding algorithm MUST protect against decoding invalid sequences."[7]The Unicode Standard calls for decoders to "...treat any ill-formed code unit sequence as an error condition. This guarantees that it will neither interpret nor emit an ill-formed code unit sequence."

Since RFC 3629 (November 2003), the low and high surrogate halves utilized by UTF-16 (U+D800 through U+DFFF) and code points not encodable by means of UTF-16 (the ones after U+10FFFF) are not legal Unicode values, and their UTF-8 encoding should be treated as an invalid byte sequence. Not deciphering unpaired surrogate halves makes it inconceivable to retailer invalid UTF-16 (such as Windows filenames or UTF-16 that has been split between the surrogates) as UTF-8.

Some implementations of decoders throw exceptions on mistakes.[27] This has the drawback that it will probably flip what would in a different way be harmless mistakes (equivalent to a "no such file" error) into a denial of service. For example early variations of Python 3.Zero would go out immediately if the command line or environment variables contained invalid UTF-8.[28] An selection observe is to replace mistakes with a alternative persona. Since Unicode 6[29] (October 2010), the standard (bankruptcy 3) has really helpful a "best practice" the place the error ends once a disallowed byte is encountered. In those decoders E1,A0,C0 is 2 mistakes (2 bytes in the first one). This approach an error is not more than three bytes lengthy and not contains the start of a legitimate persona, and there are 21,952 other imaginable errors.[30] The standard additionally recommends changing every error with the substitute persona "�" (U+FFFD).

Byte order mark

If the UTF-16 Unicode byte order mark (BOM, U+FEFF) personality is at the start of a UTF-8 report, the first 3 bytes can be 0xEF, 0xBB, 0xBF.

The Unicode Standard neither requires nor recommends the use of the BOM for UTF-8, however warns that it may be encountered at the get started of a record trans-coded from every other encoding.[31] While ASCII textual content encoded the use of UTF-8 is backward like minded with ASCII, this isn't true when Unicode Standard suggestions are disregarded and a BOM is added. A BOM can confuse device that's not prepared for it however can differently settle for UTF-8, e.g. programming languages that permit non-ASCII bytes in string literals but no longer at the start of the record. Nevertheless, there used to be and still is instrument that always inserts a BOM when writing UTF-8, and refuses to accurately interpret UTF-8 until the first persona is a BOM (or the report only comprises ASCII).

Adoption

Use of the major encodings on the web from 2001 to 2012 as recorded via Google,[32] with UTF-Eight overtaking all others in 2008 and over 60% of the internet in 2012 (since then coming near 100%). The ASCII-only determine includes all web pages that solely include ASCII characters, without reference to the declared header.

UTF-8 is the advice from the WHATWG for HTML and DOM specifications,[33] and the Internet Mail Consortium recommends that every one e mail techniques have the ability to show and create mail the use of UTF-8.[34][35] The World Wide Web Consortium recommends UTF-Eight as the default encoding in XML and HTML (and now not just the usage of UTF-8, also stating it in metadata), "even when all characters are in the ASCII range .. Using non-UTF-8 encodings can have unexpected results".[36] Many other criteria only improve UTF-8, e.g. open JSON exchange requires it.[37] Microsoft now recommends the use of UTF-Eight for applications the usage of the Windows API, while continuing to handle a legacy "Unicode" (that means UTF-16) interface.[38]

See additionally: Popularity of text encodings

UTF-Eight has been the most commonplace encoding for the World Wide Web since 2008.[39] As of April 2021, UTF-Eight accounts for on moderate 96.7% of all web pages; and 975 of the best 1,000 best possible ranked web pages.[4] This takes into consideration that ASCII is valid UTF-8.[40]

For native text recordsdata UTF-8 usage is lower, and plenty of legacy single-byte (and CJK multi-byte) encodings stay in use. The primary cause is editors that don't display or write UTF-8 until the first persona in a report is a byte order mark, making it impossible for other instrument to use UTF-Eight with out being rewritten to forget about the byte order mark on enter and add it on output.[41][42] Recently there has been some improvement, Notepad now writes UTF-Eight without a BOM by default.[43]

Internally in software usage is even decrease, with UCS-2, UTF-16, and UTF-32 in use, specifically in the Windows API, but additionally via Python,[44]JavaScript, Qt, and plenty of other cross-platform software libraries. This is due to a trust that direct indexing of code points is extra important than 8-bit compatibility (UTF-Sixteen doesn't in fact have direct indexing but it is like minded with the out of date UCS-2 which did). In recent software inner use of UTF-Eight has change into a lot higher, as this avoids the overhead of changing from/to UTF-Eight on I/O and dealing with UTF-Eight encoding errors: the default string primitive utilized in Go,[45]Julia, Rust, Swift 5,[46] and PyPy[47] are UTF-8.

History

See also: Universal Coded Character Set § History

The International Organization for Standardization (ISO) got down to compose a universal multi-byte personality set in 1989. The draft ISO 10646 standard contained a non-required annex called UTF-1 that equipped a byte circulation encoding of its 32-bit code points. This encoding was once not satisfactory on efficiency grounds, amongst other problems, and the largest problem was once more than likely that it did not have a transparent separation between ASCII and non-ASCII: new UTF-1 tools could be backward like minded with ASCII-encoded text, however UTF-1-encoded text may confuse existing code expecting ASCII (or extended ASCII), as a result of it could include continuation bytes in the vary 0x21–0x7E that supposed something else in ASCII, e.g., 0x2F for '/', the Unix trail directory separator, and this situation is reflected in the identify and introductory text of its replacement. The table below was once derived from a textual description in the annex.

UTF-1 Numberof bytes Firstcode level Lastcode level Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 1 U+0000 U+009F 00–9F 2 U+00A0 U+00FF A0 A0–FF 2 U+0100 U+4015 A1–F5 21–7E, A0–FF 3 U+4016 U+38E2D F6–FB 21–7E, A0–FF 21–7E, A0–FF 5 U+38E2E U+7FFFFFFF FC–FF 21–7E, A0–FF 21–7E, A0–FF 21–7E, A0–FF 21–7E, A0–FF

In July 1992, the X/Open committee XoJIG was searching for a better encoding. Dave Prosser of Unix System Laboratories submitted a suggestion for one who had sooner implementation characteristics and offered the development that 7-bit ASCII characters would only constitute themselves; all multi-byte sequences would come with only bytes the place the high bit was once set. The title File System Safe UCS Transformation Format (FSS-UTF) and most of the text of this proposal were later preserved in the final specification.[48][49][50][51]

FSS-UTF FSS-UTF proposal (1992) Numberof bytes Firstcode level Lastcode point Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 1 U+0000 U+007F 0xxxxxxx 2 U+0080 U+207F 10xxxxxx 1xxxxxxx 3 U+2080 U+8207F 110xxxxx 1xxxxxxx 1xxxxxxx 4 U+82080 U+208207F 1110xxxx 1xxxxxxx 1xxxxxxx 1xxxxxxx 5 U+2082080 U+7FFFFFFF 11110xxx 1xxxxxxx 1xxxxxxx 1xxxxxxx 1xxxxxxx

In August 1992, this proposal used to be circulated by way of an IBM X/Open consultant to parties. A modification by way of Ken Thompson of the Plan 9 running system workforce at Bell Labs made it somewhat less bit-efficient than the previous proposal but crucially allowed it to be self-synchronizing, letting a reader start any place and instantly stumble on byte series obstacles. It also deserted the use of biases and as a substitute added the rule that solely the shortest possible encoding is allowed; the further loss in compactness is fairly insignificant, but readers now have to appear out for invalid encodings to steer clear of reliability and especially security problems. Thompson's design was once outlined on September 2, 1992, on a placemat in a New Jersey diner with Rob Pike. In the following days, Pike and Thompson implemented it and up to date Plan Nine to make use of it all the way through, after which communicated their good fortune again to X/Open, which authorised it as the specification for FSS-UTF.[50]

FSS-UTF (1992) / UTF-8 (1993)[2] Numberof bytes Firstcode point Lastcode level Byte 1 Byte 2 Byte 3 Byte 4 Byte 5 Byte 6 1 U+0000 U+007F 0xxxxxxx 2 U+0080 U+07FF 110xxxxx 10xxxxxx 3 U+0800 U+FFFF 1110xxxx 10xxxxxx 10xxxxxx 4 U+10000 U+1FFFFF 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx 5 U+200000 U+3FFFFFF 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 6 U+4000000 U+7FFFFFFF 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx

UTF-8 used to be first officially introduced at the USENIX convention in San Diego, from January 25 to 29, 1993. The Internet Engineering Task Force adopted UTF-8 in its Policy on Character Sets and Languages in RFC 2277 (BCP 18) for long run Internet criteria paintings, changing Single Byte Character Sets akin to Latin-1 in older RFCs.[52]

In November 2003, UTF-8 was limited through RFC 3629 to check the constraints of the UTF-Sixteen personality encoding: explicitly prohibiting code points comparable to the low and high surrogate characters got rid of greater than 3% of the three-byte sequences, and finishing at U+10FFFF got rid of more than 48% of the four-byte sequences and all five- and six-byte sequences.

Standards

There are several current definitions of UTF-8 in various standards paperwork:

RFC 3629 / STD 63 (2003), which establishes UTF-8 as a standard Internet protocol component RFC 5198 defines UTF-Eight NFC for Network Interchange (2008) ISO/IEC 10646:2014 §9.1 (2014)[53] The Unicode Standard, Version 11.0 (2018)[54]

They supersede the definitions given in the following out of date works:

The Unicode Standard, Version 2.0, Appendix A (1996) ISO/IEC 10646-1:1993 Amendment 2 / Annex R (1996) RFC 2044 (1996) RFC 2279 (1998) The Unicode Standard, Version 3.0, §2.3 (2000) plus Corrigendum #1 : UTF-8 Shortest Form (2000) Unicode Standard Annex #27: Unicode 3.1 (2001)[55] The Unicode Standard, Version 5.0 (2006)[56] The Unicode Standard, Version 6.0 (2010)[57]

They are all the similar in their normal mechanics, with the main differences being on problems corresponding to allowed vary of code point values and protected dealing with of invalid input.

Comparison with different encodings

See also: Comparison of Unicode encodings

Some of the necessary options of this encoding are as follows:

Backward compatibility: Backward compatibility with ASCII and the enormous amount of software designed to process ASCII-encoded text used to be the main driving force at the back of the design of UTF-8. In UTF-8, single bytes with values in the range of Zero to 127 map immediately to Unicode code issues in the ASCII range. Single bytes in this vary represent characters, as they do in ASCII. Moreover, 7-bit bytes (bytes the place the most vital bit is 0) never seem in a multi-byte collection, and no valid multi-byte sequence decodes to an ASCII code-point. A chain of 7-bit bytes is both valid ASCII and legitimate UTF-8, and under both interpretation represents the same collection of characters. Therefore, the 7-bit bytes in a UTF-Eight flow constitute all and solely the ASCII characters in the move. Thus, many textual content processors, parsers, protocols, record codecs, text show techniques, and so on., which use ASCII characters for formatting and regulate functions, will proceed to work as supposed by treating the UTF-8 byte flow as a sequence of single-byte characters, without deciphering the multi-byte sequences. ASCII characters on which the processing turns, corresponding to punctuation, whitespace, and keep an eye on characters will never be encoded as multi-byte sequences. It is therefore secure for such processors to easily forget about or pass-through the multi-byte sequences, with out deciphering them. For example, ASCII whitespace could also be used to tokenize a UTF-8 circulation into words; ASCII line-feeds could also be used to separate a UTF-8 flow into strains; and ASCII NUL characters can be utilized to split UTF-8-encoded data into null-terminated strings. Similarly, many layout strings used by library functions like "printf" will as it should be deal with UTF-8-encoded enter arguments. Fallback and auto-detection: Only a small subset of imaginable byte strings are a valid UTF-8 string: the bytes C0, C1, and F5 through FF can't appear, and bytes with the high bit set should be in pairs, and other necessities. It is very unlikely that a readable text in any extended ASCII is valid UTF-8. Part of the popularity of UTF-8 is due to it offering a type of backward compatibility for these as well. A UTF-8 processor which erroneously receives prolonged ASCII as input can thus "auto-detect" this with very high reliability. Fallback mistakes can be false negatives, and those will be uncommon. Moreover, in lots of programs, such as text display, the end result of unsuitable fallback is normally slight. A UTF-Eight flow might merely include mistakes, resulting in the auto-detection scheme producing false positives; but auto-detection is a hit in the majority of cases, especially with longer texts, and is widely used. It also works to "fall back" or replace 8-bit bytes the use of the appropriate code-point for a legacy encoding only when errors in the UTF-8 are detected, allowing restoration although UTF-8 and legacy encoding is concatenated in the same report. Prefix code: The first byte indicates the choice of bytes in the sequence. Reading from a circulate can instantaneously decode each particular person totally won collection, without first having to watch for both the first byte of a next series or an end-of-stream indication. The length of multi-byte sequences is easily determined by people as it's simply the selection of high-order 1s in the main byte. An wrong character will not be decoded if a circulate ends mid-sequence. Self-synchronization: The main bytes and the continuation bytes don't proportion values (continuation bytes start with the bits 10 while unmarried bytes get started with 0 and longer lead bytes get started with 11). This way a seek is not going to by accident find the sequence for one persona beginning in the middle of some other character. It additionally means the get started of a personality will also be found from a random place by way of backing up at maximum Three bytes to seek out the leading byte. An incorrect personality is probably not decoded if a flow starts mid-sequence, and a shorter collection won't ever seem inside an extended one. Sorting order: The selected values of the main bytes implies that a listing of UTF-8 strings can be looked after in code level order by sorting the corresponding byte sequences.Single-byte UTF-8 can encode any Unicode character, keeping off the wish to figure out and set a "code page" or in a different way indicate what personality set is in use, and allowing output in a couple of scripts at the identical time. For many scripts there have been more than one single-byte encoding in usage, so even understanding the script used to be insufficient data to show it accurately. The bytes 0xFE and 0xFF do not appear, so a legitimate UTF-Eight flow never fits the UTF-16 byte order mark and thus can't be at a loss for words with it. The absence of 0xFF (0377) also removes the want to get away this byte in Telnet (and FTP keep watch over connection). UTF-8 encoded textual content is larger than specialised single-byte encodings excluding for plain ASCII characters. In the case of scripts which used 8-bit personality sets with non-Latin characters encoded in the higher part (similar to most Cyrillic and Greek alphabet code pages), characters in UTF-Eight can be double the size. For some scripts, equivalent to Thai and Devanagari (which is used by various South Asian languages), characters will triple in size. There are even examples where a single byte turns into a composite personality in Unicode and is thus six times greater in UTF-8. This has led to objections in India and different international locations. It is conceivable in UTF-8 (or some other variable-length encoding) to separate or truncate a string in the heart of a character. If the two items don't seem to be re-appended later sooner than interpretation as characters, it will introduce an invalid sequence at both the finish of the previous segment and the get started of the subsequent, and some decoders is not going to keep those bytes and result in knowledge loss. Because UTF-8 is self-synchronizing this will on the other hand by no means introduce a unique legitimate persona, and it is also relatively simple to transport the truncation point backward to the start of a personality. If the code issues are all the same length, measurements of a hard and fast number of them is straightforward. Due to ASCII-era documentation the place "character" is used as a synonym for "byte" this is regularly thought to be important. However, by means of measuring string positions the use of bytes instead of "characters" maximum algorithms may also be easily and efficiently tailored for UTF-8. Searching for a string inside a long string can for example be performed byte by byte; the self-synchronization assets prevents false positives.Other multi-byte UTF-8 can encode any Unicode persona. Files in different scripts will also be displayed as it should be without having to choose the proper code page or font. For instance, Chinese and Arabic can be written in the same report without specialised markup or guide settings that explain an encoding. UTF-Eight is self-synchronizing: personality boundaries are simply known via scanning for well-defined bit patterns in both route. If bytes are misplaced because of error or corruption, one can always find the subsequent valid character and resume processing. If there's a wish to shorten a string to suit a specified field, the earlier legitimate personality can simply be discovered. Many multi-byte encodings comparable to Shift JIS are much more difficult to resynchronize. This also means that byte-oriented string-searching algorithms can be used with UTF-8 (as a character is the similar as a "word" made up of that many bytes), optimized variations of byte searches can be a lot faster due to hardware improve and look up tables that experience solely 256 entries. Self-synchronization does however require that bits be reserved for those markers in each and every byte, increasing the size. Efficient to encode the usage of simple bitwise operations. UTF-Eight does not require slower mathematical operations similar to multiplication or division (not like Shift JIS, GB 2312 and other encodings). UTF-Eight will take more room than a multi-byte encoding designed for a particular script. East Asian legacy encodings typically used two bytes per personality yet take 3 bytes in keeping with personality in UTF-8.UTF-16 Byte encodings and UTF-Eight are represented by means of byte arrays in systems, and steadily not anything must be accomplished to a function when converting supply code from a byte encoding to UTF-8. UTF-16 is represented by way of 16-bit word arrays, and changing to UTF-Sixteen while keeping up compatibility with current ASCII-based techniques (equivalent to was once achieved with Windows) calls for every API and information construction that takes a string to be duplicated, one model accepting byte strings and every other model accepting UTF-16. If backward compatibility isn't needed, all string dealing with nonetheless will have to be changed. Text encoded in UTF-Eight will be smaller than the identical textual content encoded in UTF-Sixteen if there are extra code points under U+0080 than in the range U+0800..U+FFFF. This is true for all modern European languages. It is frequently true even for languages like Chinese, due to the large selection of areas, newlines, digits, and HTML markup in conventional files. Most verbal exchange (e.g. HTML and IP) and storage (e.g. for Unix) used to be designed for a circulate of bytes. A UTF-16 string must use a couple of bytes for every code unit: The order of the ones two bytes turns into an issue and should be laid out in the UTF-Sixteen protocol, such as with a byte order mark. If an unusual number of bytes is lacking from UTF-16, the entire remainder of the string will be meaningless textual content. Any bytes missing from UTF-8 will nonetheless allow the textual content to be recovered accurately starting with the subsequent personality after the missing bytes.

Derivatives

The following implementations show slight differences from the UTF-8 specification. They are incompatible with the UTF-Eight specification and could also be rejected by way of conforming UTF-Eight applications.

CESU-8 Main article: CESU-8

Unicode Technical Report #26[58] assigns the title CESU-8 to a nonstandard variant of UTF-8, in which Unicode characters in supplementary planes are encoded the usage of six bytes, somewhat than the 4 bytes required through UTF-8. CESU-8 encoding treats every half of a four-byte UTF-Sixteen surrogate pair as a two-byte UCS-2 character, yielding two three-byte UTF-8 characters, which in combination constitute the authentic supplementary personality. Unicode characters inside the Basic Multilingual Plane seem as they would most often in UTF-8. The Report was once written to recognize and formalize the life of information encoded as CESU-8, despite the Unicode Consortium discouraging its use, and notes that a conceivable intentional reason why for CESU-8 encoding is preservation of UTF-Sixteen binary collation.

CESU-Eight encoding may result from changing UTF-16 data with supplementary characters to UTF-8, using conversion strategies that assume UCS-2 information, which means they are unaware of four-byte UTF-16 supplementary characters. It is primarily a subject on working methods which broadly use UTF-16 internally, reminiscent of Microsoft Windows.

In Oracle Database, the UTF8 personality set uses CESU-8 encoding, and is deprecated. The AL32UTF8 personality set uses standards-compliant UTF-Eight encoding, and is most well-liked.[59][60]

CESU-Eight is illegitimate to be used in HTML5 paperwork.[61][62][63]

MySQL utf8mb3

In MySQL, the utf8mb3 personality set is defined to be UTF-8 encoded information with a maximum of 3 bytes consistent with persona, that means solely Unicode characters in the Basic Multilingual Plane (i.e. from UCS-2) are supported. Unicode characters in supplementary planes are explicitly now not supported. utf8mb3 is deprecated in want of the utf8mb4 persona set, which makes use of standards-compliant UTF-Eight encoding. utf8 is an alias for utf8mb3, however is meant to become an alias to utf8mb4 in a future free up of MySQL.[64] It is possible, despite the fact that unsupported, to retailer CESU-Eight encoded data in utf8mb3, via handling UTF-16 information with supplementary characters as regardless that it's UCS-2.

Modified UTF-8

Modified UTF-8 (MUTF-8) originated in the Java programming language. In Modified UTF-8, the null personality (U+0000) uses the two-byte overlong encoding 11000000 10000000 (hexadecimal C0 80), as a substitute of 00000000 (hexadecimal 00).[65] Modified UTF-8 strings by no means include any exact null bytes but can comprise all Unicode code points together with U+0000,[66] which permits such strings (with a null byte appended) to be processed through conventional null-terminated string functions. All known Modified UTF-8 implementations additionally treat the surrogate pairs as in CESU-8.

In standard usage, the language helps standard UTF-Eight when studying and writing strings through InputStreamReader and OutputStreamAuthor (whether it is the platform's default persona set or as asked by way of the program). However it uses Modified UTF-Eight for object serialization[67] among other applications of DataInput and DataOutput, for the Java Native Interface,[68] and for embedding constant strings in school recordsdata.[69]

The dex layout explained through Dalvik also makes use of the same changed UTF-8 to constitute string values.[70]Tcl additionally makes use of the identical modified UTF-8[71] as Java for inside representation of Unicode knowledge, however uses strict CESU-Eight for exterior data.

WTF-8

In WTF-8 (Wobbly Transformation Format, 8-bit) unpaired surrogate halves (U+D800 by way of U+DFFF) are allowed.[72] This is essential to retailer possibly-invalid UTF-16, corresponding to Windows filenames. Many systems that handle UTF-8 paintings this way without making an allowance for it a unique encoding, as it is simpler.[73]

(The term "WTF-8" has also been used humorously to check with erroneously doubly-encoded UTF-8[74][75] every now and then with the implication that CP1252 bytes are the solely ones encoded)[76]

PEP 383

Version 3 of the Python programming language treats each and every byte of an invalid UTF-Eight bytestream as an error (see additionally adjustments with new UTF-8 mode in Python 3.7[77]); this offers 128 other imaginable mistakes. Extensions were created to permit any byte sequence that is assumed to be UTF-Eight to be losslessly transformed to UTF-Sixteen or UTF-32, by means of translating the 128 possible error bytes to reserved code points, and remodeling those code points again to error bytes to output UTF-8. The maximum commonplace way is to translate the codes to U+DC80...U+DCFF which are low (trailing) surrogate values and thus "invalid" UTF-16, as used by Python's PEP 383 (or "surrogateescape") means.[78] Another encoding known as MirBSD OPTU-8/16 converts them to U+EF80...U+EFFF in a Private Use Area.[79] In both way, the byte value is encoded in the low eight bits of the output code level.

These encodings are very useful because they keep away from the want to deal with "invalid" byte strings until a lot later, if at all, and allow "text" and "data" byte arrays to be the identical object. If a program desires to make use of UTF-Sixteen internally those are required to maintain and use filenames that may use invalid UTF-8;[80] as the Windows filesystem API uses UTF-16, the want to fortify invalid UTF-Eight is less there.[78]

For the encoding to be reversible, the standard UTF-8 encodings of the code points used for misguided bytes will have to be considered invalid. This makes the encoding incompatible with WTF-8 or CESU-8 (even though only for 128 code issues). When re-encoding it is vital to watch out of sequences of error code points which convert back to valid UTF-8, that may be utilized by malicious instrument to get unexpected characters in the output, regardless that this can not produce ASCII characters so it is regarded as comparatively protected, since malicious sequences (reminiscent of cross-site scripting) generally rely on ASCII characters.[80]

See additionally

Alt code Character encodings in HTML Comparison of e-mail shoppers#Features Comparison of Unicode encodings GB 18030 UTF-EBCDIC Iconv Specials (Unicode block) Unicode and electronic mail Unicode and HTML Percent-encoding#Current standard

Notes

^ 17 planes occasions 216 code points in keeping with airplane, minus 211 technically-invalid surrogates. ^ You may expect better code points than U+10FFFF to be expressible, but in RFC3629 §3 UTF-8 is limited to compare the limits of UTF-16. (As §12 notes, this is changed from RFC 2279.)

References

^ .mw-parser-output cite.citationfont-style:inherit.mw-parser-output .citation qquotes:"\"""\"""'""'".mw-parser-output .id-lock-free a,.mw-parser-output .citation .cs1-lock-free abackground:linear-gradient(transparent,clear),url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat.mw-parser-output .id-lock-limited a,.mw-parser-output .id-lock-registration a,.mw-parser-output .citation .cs1-lock-limited a,.mw-parser-output .quotation .cs1-lock-registration abackground:linear-gradient(transparent,clear),url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em middle/9px no-repeat.mw-parser-output .id-lock-subscription a,.mw-parser-output .quotation .cs1-lock-subscription abackground:linear-gradient(clear,transparent),url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat.mw-parser-output .cs1-subscription,.mw-parser-output .cs1-registrationcolour:#555.mw-parser-output .cs1-subscription span,.mw-parser-output .cs1-registration spanborder-bottom:1px dotted;cursor:help.mw-parser-output .cs1-ws-icon abackground:linear-gradient(clear,clear),url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")correct 0.1em heart/12px no-repeat.mw-parser-output code.cs1-codecolor:inherit;background:inherit;border:none;padding:inherit.mw-parser-output .cs1-hidden-errorshow:none;font-size:100%.mw-parser-output .cs1-visible-errorfont-size:100%.mw-parser-output .cs1-maintdisplay:none;colour:#33aa33;margin-left:0.3em.mw-parser-output .cs1-formatfont-size:95%.mw-parser-output .cs1-kern-left,.mw-parser-output .cs1-kern-wl-leftpadding-left:0.2em.mw-parser-output .cs1-kern-right,.mw-parser-output .cs1-kern-wl-rightpadding-right:0.2em.mw-parser-output .citation .mw-selflinkfont-weight:inherit"Chapter 2. General Structure". The Unicode Standard (6.0 ed.). Mountain View, California, US: The Unicode Consortium. ISBN 978-1-936213-01-6. ^ a b Pike, Rob (30 April 2003). "UTF-8 history". ^ Pike, Rob; Thompson, Ken (1993). "Hello World or Καλημέρα κόσμε or こんにちは 世界" (PDF). Proceedings of the Winter 1993 USENIX Conference. ^ a b "Usage Survey of Character Encodings broken down by Ranking". w3techs.com. Retrieved 2021-04-01. ^ a b "Character Sets". Internet Assigned Numbers Authority. 2013-01-23. Retrieved 2013-02-08. ^ Dürst, Martin. "Setting the HTTP charset parameter". W3C. Retrieved 2013-02-08. ^ a b Yergeau, F. (2003). UTF-8, a transformation structure of ISO 10646. Internet Engineering Task Force. doi:10.17487/RFC3629. RFC 3629. Retrieved 2015-02-03. ^ "Encoding Standard § 4.2. Names and labels". WHATWG. Retrieved 2018-04-29. ^ "BOM". suikawiki (in Japanese). Retrieved 2013-04-26. ^ Davis, Mark. "Forms of Unicode". IBM. Archived from the original on 2005-05-06. Retrieved 2013-09-18. ^ Liviu (2014-02-07). "UTF-8 codepage 65001 in Windows 7 - part I". Retrieved 2018-01-30. ^ "Script How to set default encoding to UTF-8 for notepad by PowerShell". gallery.technet.microsoft.com. Retrieved 2018-01-30. ^ "HP PCL Symbol Sets | Printer Control Language (PCL & PXL) Support Blog". 2015-02-19. Archived from the authentic on 2015-02-19. Retrieved 2018-01-30. ^ Allen, Julie D.; Anderson, Deborah; Becker, Joe; Cook, Richard, eds. (2012). "The Unicode Standard, Version 6.1". Mountain View, California: Unicode Consortium. Cite magazine requires |magazine= (lend a hand) ^ "Apple Developer Documentation". developer.apple.com. Retrieved 2021-03-15. ^ "It's not wrong that "🤦🏼‍♂️".length == 7". hsivonen.fi. Retrieved 2021-03-15. zero width joiner persona in |identify= at place 24 (lend a hand) ^ "BinaryString (flink 1.9-SNAPSHOT API)". ci.apache.org. Retrieved 2021-03-24. ^ "Chapter 3" (PDF), The Unicode Standard, p. 54 ^ "Chapter 3" (PDF), The Unicode Standard, p. 55 ^ "Chapter 3" (PDF), The Unicode Standard, p. 55 ^ "Chapter 3" (PDF), The Unicode Standard, p. 54 ^ Yergeau, F. (November 2003). UTF-8, a change format of ISO 10646. IETF. doi:10.17487/RFC3629. STD 63. RFC 3629. Retrieved August 20, 2020. ^ "Chapter 3" (PDF), The Unicode Standard, p. 55 ^ Yergeau, F. (November 2003). UTF-8, a transformation layout of ISO 10646. IETF. doi:10.17487/RFC3629. STD 63. RFC 3629. Retrieved August 20, 2020. ^ Marin, Marvin (2000-10-17). "Web Server Folder Traversal MS00-078". ^ "Summary for CVE-2008-2938". National Vulnerability Database. ^ "DataInput (Java Platform SE 8)". medical doctors.oracle.com. Retrieved 2021-03-24. ^ "Non-decodable Bytes in System Character Interfaces". python.org. 2009-04-22. Retrieved 2014-08-13. ^ "Unicode 6.0.0". ^ 128 1-byte, (16+5)×Sixty four 2-byte, and 5×64×64 3-byte. There is also somewhat fewer if extra actual checks are executed for each continuation byte. ^ "Chapter 2" (PDF), The Unicode Standard, p. 30 ^ Davis, Mark (2012-02-03). "Unicode over 60 percent of the web". Official Google Blog. Archived from the unique on 2018-08-09. Retrieved 2020-07-24. ^ "Encoding Standard". encoding.spec.whatwg.org. Retrieved 2020-04-15. ^ "Using International Characters in Internet Mail". Internet Mail Consortium. 1998-08-01. Archived from the original on 2007-10-26. Retrieved 2007-11-08. ^ "Encoding Standard". encoding.spec.whatwg.org. Retrieved 2018-11-15. ^ "Specifying the document's character encoding". HTML5.2. World Wide Web Consortium. 14 December 2017. Retrieved 2018-06-03. ^ "The JavaScript Object Notation (JSON) Data Interchange Format". IETF. December 2017. Retrieved 16 February 2018. ^ "Use the Windows UTF-8 code page". UWP programs. docs.microsoft.com. Retrieved 2020-06-06. ^ Davis, Mark (2008-05-05). "Moving to Unicode 5.1". Retrieved 2021-02-19. ^ "Usage Statistics and Market Share of US-ASCII for Websites, August 2020". w3techs.com. Retrieved 2020-08-28. ^ "How can I make Notepad to save text in UTF-8 without the BOM?". Stack Overflow. Retrieved 2021-03-24. ^ Galloway, Matt. "Character encoding for iOS developers. Or UTF-8 what now?". www.galloway.me.uk. Retrieved 2021-01-02. in truth, you most often just assume UTF-Eight since this is by means of far the maximum commonplace encoding. ^ "Windows 10 Notepad is Getting Better UTF-8 Encoding Support". BleepingComputer. Retrieved 2021-03-24. Microsoft is now defaulting to saving new textual content recordsdata as UTF-Eight without BOM as proven underneath. ^ "PEP 623 -- Remove wstr from Unicode". Python.org. Retrieved 2020-11-21. Until we drop legacy Unicode object, it is very onerous to take a look at other Unicode implementation like UTF-Eight based implementation in PyPy ^ "The Go Programming Language Specification". Retrieved 2021-02-10. ^ Tsai, Michael J. "Michael Tsai - Blog - UTF-8 String in Swift 5". Retrieved 2021-03-15. ^ Mattip (2019-03-24). "PyPy Status Blog: PyPy v7.1 released; now uses utf-8 internally for unicode strings". PyPy Status Blog. Retrieved 2020-11-21. ^ "Appendix F. FSS-UTF / File System Safe UCS Transformation format" (PDF). The Unicode Standard 1.1. Archived (PDF) from the unique on 2016-06-07. Retrieved 2016-06-07. ^ Whistler, Kenneth (2001-06-12). "FSS-UTF, UTF-2, UTF-8, and UTF-16". Archived from the original on 2016-06-07. Retrieved 2006-06-07. ^ a b Pike, Rob (2003-04-30). "UTF-8 history". Retrieved 2012-09-07. ^ Pike, Rob (2012-09-06). "UTF-8 turned 20 years old yesterday". Retrieved 2012-09-07. ^ Alvestrand, Harald (January 1998). IETF Policy on Character Sets and Languages. doi:10.17487/RFC2277. BCP 18. ^ ISO/IEC 10646:2014 §9.1, 2014. ^ The Unicode Standard, Version 11.0 §3.Nine D92, §3.10 D95, 2018. ^ Unicode Standard Annex #27: Unicode 3.1, 2001. ^ The Unicode Standard, Version 5.0 §3.9–§3.10 ch. 3, 2006. ^ The Unicode Standard, Version 6.0 §3.9 D92, §3.10 D95, 2010. ^ McGowan, Rick (2011-12-19). "Compatibility Encoding Scheme for UTF-16: 8-Bit (CESU-8)". Unicode Consortium. Unicode Technical Report #26. ^ "Character Set Support". Oracle Database 19c Documentation, SQL Language Reference. Oracle Corporation. ^ "Supporting Multilingual Databases with Unicode § Support for the Unicode Standard in Oracle Database". Database Globalization Support Guide. Oracle Corporation. ^ "8.2.2.3. Character encodings". HTML 5.1 Standard. W3C. ^ "8.2.2.3. Character encodings". HTML 5 Standard. W3C. ^ "12.2.3.3 Character encodings". HTML Living Standard. WHATWG. ^ "The utf8mb3 Character Set (3-Byte UTF-8 Unicode Encoding)". MySQL 8.0 Reference Manual. Oracle Corporation. ^ "Java SE documentation for Interface java.io.DataInput, subsection on Modified UTF-8". Oracle Corporation. 2015. Retrieved 2015-10-16. ^ "The Java Virtual Machine Specification, section 4.4.7: "The CONSTANT_Utf8_info Structure"". Oracle Corporation. 2015. Retrieved 2015-10-16. ^ "Java Object Serialization Specification, chapter 6: Object Serialization Stream Protocol, section 2: Stream Elements". Oracle Corporation. 2010. Retrieved 2015-10-16. ^ "Java Native Interface Specification, chapter 3: JNI Types and Data Structures, section: Modified UTF-8 Strings". Oracle Corporation. 2015. Retrieved 2015-10-16. ^ "The Java Virtual Machine Specification, section 4.4.7: "The CONSTANT_Utf8_info Structure"". Oracle Corporation. 2015. Retrieved 2015-10-16. ^ "ART and Dalvik". Android Open Source Project. Archived from the authentic on 2013-04-26. Retrieved 2013-04-09. ^ "Tcler's Wiki: UTF-8 bit by bit (Revision 6)". 2009-04-25. Retrieved 2009-05-22. ^ Sapin, Simon (2016-03-11) [2014-09-25]. "The WTF-8 encoding". Archived from the original on 2016-05-24. Retrieved 2016-05-24. ^ Sapin, Simon (2015-03-25) [2014-09-25]. "The WTF-8 encoding § Motivation". Archived from the unique on 2016-05-24. Retrieved 2020-08-26. ^ "WTF-8.com". 2006-05-18. Retrieved 2016-06-21. ^ Speer, Robyn (2015-05-21). "ftfy (fixes text for you) 4.0: changing less and fixing more". Archived from the original on 2015-05-30. Retrieved 2016-06-21. ^ "WTF-8, a transformation format of code page 1252". Archived from the original on 2016-10-13. Retrieved 2016-10-12. ^ "PEP 540 -- Add a new UTF-8 Mode". Python.org. Retrieved 2021-03-24. ^ a b von Löwis, Martin (2009-04-22). "Non-decodable Bytes in System Character Interfaces". Python Software Foundation. PEP 383. ^ "RTFM optu8to16(3), optu8to16vis(3)". www.mirbsd.org. ^ a b Davis, Mark; Suignard, Michel (2014). "3.7 Enabling Lossless Conversion". Unicode Security Considerations. Unicode Technical Report #36.

External links

Original UTF-Eight paper (or pdf) for Plan 9 from Bell Labs UTF-8 test pages: Andreas Prilop Jost Gippert World Wide Web Consortium Unix/Linux: UTF-8/Unicode FAQ, Linux Unicode HOWTO, 8.xml UTF-Eight and Gentoo Characters, Symbols and the Unicode Miracle on YouTubevteUnicodeUnicode Unicode Consortium ISO/IEC 10646 (Universal Character Set) VersionsCode issues Block List Universal Character Set Character charts Character assets Plane Private Use AreaCharactersSpecial objective BOM Combining Grapheme Joiner Left-to-right mark / Right-to-left mark Soft hyphen Variant form Word joiner Zero-width joiner Zero-width non-joiner Zero-width areaLists Characters CJK Unified Ideographs Combining personality Duplicate characters Numerals Scripts Spaces Symbols Halfwidth and fullwidth Alias names and abbreviationsProcessingAlgorithms Bidirectional text Collation ISO/IEC 14651 Equivalence Variation sequences International Ideographs CoreComparison BOCU-1 CESU-8 Punycode SCSU UTF-1 UTF-7 UTF-8 UTF-16/UCS-2 UTF-32/UCS-4 UTF-EBCDICOn pairs ofcode points Combining personality Compatibility characters Duplicate characters Equivalence Homoglyph Precomposed persona list Z-variant Variation sequences Regional Indicator Symbol Emoji pores and skin colorUsage Domain names (IDN) Email Fonts HTML entity references numeric references Input International Ideographs CoreRelated criteria Common Locale Data Repository (CLDR) GB 18030 ISO/IEC 8859 ISO 15924Related subjects Anomalies ConScript Unicode Registry Ideographic Research Group International Components for Unicode People concerned with Unicode Han unificationScripts and emblems in UnicodeCommon and inherited scripts Combining marks Diacritics Punctuation Space NumbersModern scripts Adlam Arabic Armenian Balinese Bamum Batak Bengali Bopomofo Braille Buhid Burmese Canadian Aboriginal Chakma Cham Cherokee CJK Unified Ideographs (Han) Cyrillic Deseret Devanagari Geʽez Georgian Greek Gujarati Gunjala Gondi Gurmukhi Hangul Hanifi Rohingya Hanja Hanunuo Hebrew Hiragana Javanese Kanji Kannada Katakana Kayah Li Khmer Lao Latin Lepcha Limbu Lisu (Fraser) Lontara Malayalam Masaram Gondi Mende Kikakui Medefaidrin Miao (Pollard) Mongolian Mru N'Ko New Tai Lue Nüshu Nyiakeng Puachue Hmong Odia Ol Chiki Osage Osmanya Pahawh Hmong Pau Cin Hau Pracalit (Newa) Ranjana Rejang Samaritan Saurashtra Shavian Sinhala Sorang Sompeng Sundanese Syriac Tagbanwa Tai Le Tai Tham Tai Viet Tamil Telugu Thaana Thai Tibetan Tifinagh Tirhuta Vai Wancho Warang Citi YiAncient andhistoric scripts Ahom Anatolian hieroglyphs Ancient North Arabian Avestan Bassa Vah Bhaiksuki Brāhmī Carian Caucasian Albanian Coptic Cuneiform Cypriot Dives Akuru Dogra Egyptian hieroglyphs Elbasan Elymaic Glagolitic Gothic Grantha Hatran Imperial Aramaic Inscriptional Pahlavi Inscriptional Parthian Kaithi Kharosthi Khitan small script Khojki Khudawadi Khwarezmian (Chorasmian) Linear A Linear B Lycian Lydian Mahajani Makasar Mandaic Manichaean Marchen Meetei Mayek Meroitic Modi Multani Nabataean Nandinagari Ogham Old Hungarian Old Italic Old Permic Old Persian cuneiform Old Sogdian Old Turkic Palmyrene ʼPhags-pa Phoenician Psalter Pahlavi Runic Sharada Siddham Sogdian South Arabian Soyombo Sylheti Nagri Tagalog (Baybayin) Takri Tangut Ugaritic Yezidi Zanabazar Sq.Notational scripts Duployan SignWritingSymbols, emojis Cultural, political, and spiritual symbols Currency Mathematical operators and logos Phonetic symbols (together with IPA) Emoji  Category: Unicode  Category: Unicode blocks vteCharacter encodingsEarly telecommunications Telegraph code Needle Morse Non-Latin Wabun/Kana Chinese Cyrillic Korean Baudot and Murray FIELDATA ASCII ISO/IEC 646 BCDIC 353 355 357 358 359 360 EBCDIC Teletex and Videotex/Teletext ISO/IEC 6937 / ITU T.51 ITU T.61 ITU T.101 World System Teletext background setsISO/IEC 8859 Approved -1 -2 -3 -4 -5 -6 -7 -8 -9 -10 -11 -13 -14 -15 -16 Abandoned -12 Adaptations ISO-IR-182 ISO-IR-200 ISO-IR-201 Proposed but now not authorized ISO-IR-111 ISO-IR-197 French/Dutch/Turkish draftBibliographic use MARC-8 ANSEL CCCII/EACC ISO 5426 / 5426-2 / 5427 / 5428 / 6438 / 6861 / 6862 / 10585 / 10586 / 10754 / 11822National standards ArmSCII BraSCII CNS 11643 ELOT 927 GOST 10859 GB 2312 GB 12052 GB 18030 HKSCS I.S. 434 ISCII JIS X 0201 JIS X 0208 JIS X 0212 JIS X 0213 KOI-7 KPS 9566 KS X 1001 KS X 1002 LST 1284 LST 1564 LST 1590-1 LST 1590-2 LST 1590-3 LST 1590-4 PASCII RUSCII SI 960 TIS-620 TSCII VISCII VSCII YUSCIIISO/IEC 2022 7-bit CN CN-EXT JP JP-EXT JP-1 JP-2 JP-3 KR ISO/IEC 4873 ISO/IEC 8859 ISO/IEC 10367 Extended Unix Code / EUC CN KR JP TWMac OS code pages("scripts") Armenian Arabic Barents Cyrillic Celtic CentEuro ChineseSimp / EUC-CN ChineseTrad / Big5 Croatian Cyrillic Devanagari / ISCII Dingbats Farsi (Persian) Gaelic Georgian Greek Gujarati / ISCII Gurmukhi / ISCII Hebrew Iceland Inuit Japanese / Shift JIS Keyboard Korean / EUC-KR Latin (Kermit) Maltese/Esperanto Ogham / I.S. 434 Roman Romanian Sámi Symbol Thai / TIS-620 Turkish Turkic Cyrillic Ukrainian VT100DOS code pages 100 111 112 113 151 152 161 162 163 164 165 166 210 220 301 437 449 489 620 667 668 707 708 709 710 711 714 715 720 721 737 768 770 771 772 773 774 775 776 777 778 790 850 851 852 853 854 855/872 856 857 858 859 860 861 862 863 864 865 866/808 867 868 869 874/1161/1162 876 877 878 881 882 883 884 885 891 895 896 897 898 899 900 903 904 906 907 909 910 911 926 927 928 929 932 934 936 938 941 942 943 944 946 947 948 949 950/1370 951 966 991 1034 1039 1040 1041 1042 1043 1044 1046 1086 1088 1092 1093 1098 1108 1109 1114 1115 1116 1117 1118 1119 1125/848 1126 1127 1131/849 1139 1167 1168 1300 1351 1361 1362 1363 1372 1373 1374 1375 1380 1381 1385 1386 1391 1392 1393 1394 3012 3021 3843 3844 3845 3846 3847 3848 30000 30001 30002 30003 30004 30005 30006 30007 30008 30009 30010 30011 30012 30013 30014 30015 30016 30017 30018 30019 30020 30021 30022 30023 30024 30025 30026 30027 30028 30029 30030 30031 30032 30033 30034 30039 30040 58152 58210 58335 59234 59829 60258 60853 61282 62306 CS Indic CSX Indic CSX+ Indic CWI-2 Iran System Kamenický KOI8 Mazovia MIKIBM AIX code pages 367 371 806 813 819 895 896 912 913 914 915 916 919 920 921/901 922/902 923 952 953 954 955 956 957 958 959 960 961 963 964 965 970 971 1004 1006 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1029 1036 1089 1111 1124 1129/1163 1133 1350 1382 1383IBM code pages forother distributors' encodings Apple Macintosh 1275 1280 1281 1282 1283 1284 1285 1286 Adobe 1038 1276 1277 DEC 1020 1021 1023 1090 1100 1101 1102 1103 1104 1105 1106 1107 1287 1288 HP 1050 1051 1052 1053 1054 1055 1056 1057 1058Windows code pages CER-GS 874/1162 (TIS-620) 932/943 (Shift JIS) 936/1386 (GBK) 950/1370 (Big5) 949/1363 (EUC-KR) 1169 1174 Extended Latin-8 1200 (UTF-16LE) 1201 (UTF-16BE) 1250 1251 1252 1253 1254 1255 1256 1257 1258 1261 1270 54936 (GB18030) Armenian Cyrillic + Finnish Cyrillic + French Cyrillic + German Polytonic Greek 65001 (UTF-8)Microsoft code pages forother distributors' encodings Apple Macintosh 10000 10001 10002 10003 10004 10005 10006 10007 10008 10010 10017 10021 10029 10079 10081 10082EBCDIC code pages 37 390 391 392 393 394 395 435 829 834 835 837 839 881 882 883 884 885 886 887 888 889 890 931 933/1364 935/1388 937/1371 939/1399 1001 1003 1005 1007 1024 1027 1028 1030 1031 1032 1033 1037 1068 1071 1073 1074 1075 1076 1077 1078 1080 1082 1083 1085 1087 1091 1136 1150 1151 1152 1278 1279 1303 1364 1376 1377DEC terminals (VTx) Multinational (MCS) National Replacement (NRCS) French Canadian Swiss Spanish United Kingdom Dutch Finnish French Norwegian and Danish Swedish Norwegian and Danish (choice) 8-bit Greek 8-bit Turkish 7-bit Hebrew 8-bit Hebrew Special Graphics Technical (TCS)Platform specific Acorn Adobe Standard Adobe Latin 1 Amstrad CPC Apple I Apple II Apple III ATASCII Atari ST BICS Casio calculators CDC Compucolor II CP/M+ DEC RADIX 50 DEC MCS/NRCS DG International ELWRO-Junior FIELDATA GEM GEOS GSM 03.38 HP Roman Extension HP Roman-8 HP Roman-9 HP FOCAL HP RPL IBM SQUOZE LICS LMBCS Mattel Aquarius Minitel MSX NEC APC NeXT OricSCII PCW PETSCII Sega SC-3000 Sharp calculators Sharp MZ Sinclair QL Teletext TI calculators TRS-80 Ventura International Ventura Symbol WISCII XCCS ZX80 ZX81 ZX SpectrumUnicode / ISO/IEC 10646 UTF-1 UTF-7 UTF-8 UTF-16 (UTF-16LE/UTF-16BE) / UCS-2 UTF-32 (UTF-32LE/UTF-32BE) / UCS-4 UTF-EBCDIC GB 18030 BOCU-1 CESU-8 SCSUTeX typesetting gadget Cork IL1 IL2 IL3 L7X LGR LY1 OML OMS OMX OT1 OT2 OT3 OT4 PL0 QX T2A T2B T2C T2D T3 T4 T5 TS1 TS3 U X2Miscellaneous code pages ABICOMP APL 293 310 (Graphic Escape) 351 (GDDM) 907 (OEM) ISO-IR-68 ARIB STD-B24 HZ IEC-P27-1 INIS 7-bit 8-bit Cyrillic ISO-IR-169 ISO 2033 Johab Mojikyō SEASCII Stanford/ITS TACE16 TRON UTF-5 UTF-6 WTF-8Control and nonprinting character units Morse prosigns C0 and C1 keep watch over codes ISO/IEC 6429 / ANSI X3.64 / ECMA-48 / JIS X 0211 ISO 6630 DIN 31626 JIS X 0207 ITU T.101 C0 C1 EBCDIC regulate codes Unicode control, layout and separator characters Whitespace charactersRelated subjects Code web page Windows code web page CCSID Character encodings in HTML Charset detection Han unification Hardware MojibakeCharacter units vteRob PikeRunning methods Plan Nine from Bell Labs InfernoProgramming languages Newsqueak Limbo Go SawzallSoftware acme Blit sam rio 8½Publications The Practice of Programming The Unix Programming EnvironmentOther Renée French Mark V. Shaney UTF-8 vteKen ThompsonRunning programs Unix Plan Nine from Bell Labs InfernoProgramming languages B Bon GoSoftware Belle ed grep sam Space Travel Thompson shellOther UTF-8 Retrieved from "https://en.wikipedia.org/w/index.php?title=UTF-8&oldid=1015446145"

2.png - 3 Why did UTF-8 replace the ASCII character ...

2.png - 3 Why did UTF-8 replace the ASCII character ...

2.png - 3 Why did UTF-8 replace the ASCII character ...

Technical Support Fundamental Flashcards | Quizlet

Share this

artnews