LazUTF8 unit

Routines for managing UTF-8-encoded strings.

lazutf8.pas contains useful routines for managing UTF-8-encoded strings. All routines are thread-safe unless explicitly stated.

lazutf8.pas is part of the LazUtils package.

Classes and records

TStringListUTF8Fast class Implements a string list using fast ASCII comparison functions when its data is pure ASCII.

Procedures and functions

`ConsoleToUTF8`	function	Converts an OEM-encoded string to UTF8.
`ConvertUTF16ToUTF8`	function	Converts values from UTF-16 encoding to UTF-8 encoding.
`ConvertUTF8ToUTF16`	function	Converts values from UTF-8 encoding to UTF-16 encoding.
`FindInvalidUTF8Codepoint`	function	Finds the position where an invalid UTF-8 codepoint is found in the string.
`GetEnvironmentStringUTF8`	function	Returns a system environment string.
`GetEnvironmentVariableCountUTF8`	function	Returns the number of system environment variables.
`GetEnvironmentVariableUTF8`	function	Returns the value of a system environment variable.
`IsAscii`	function	Returns True when the specified string contains only single-byte ASCII characters.
`IsPureAscii`	function	Determines whether the specified string contains only single-byte ASCII characters.
`NeedRTLAnsi`	function	Indicates if the OS requires use of AnsiToUTF8 and UTF8ToAnsi for the RTL.
`ParamStrUTF8`	function	Gets the specified command line parameter and converts it to a UTF-8-encoded string.
`SetNeedRTLAnsi`	procedure	Sets the value for the unit global variable.
`SysErrorMessageUTF8`	function	Gets the UTF-8-encoded system error message for the specified error code.
`SysToUTF8`	function	Converts strings (and format settings) from the system codepage to UTF-8.
`UnicodeToUTF8`	function	Encodes the given code point as an UTF-8 sequence of 1 to 4 bytes.
`UnicodeToUTF8Inline`	function	Encodes the given code point as an UTF-8 sequence of 1 to 4 bytes.
`UnicodeToUTF8SkipErrors`	function	Stores a single Unicode codepoint as a UTF-8-encoded value in the buffer.
`UTF16ToUTF8`	function	Converts a UTF-16-encoded string (system endian) to UTF-8 encoding.
`UTF8AddChar`	function	Adds the specified number of UTF-8 codepoints to a string.
`UTF8AddCharR`	function	Appends the specified number of UTF-8 codepoints to a string.
`UTF8CodepointCount`	function	Gets the number of valid UTF-8 codepoints in the specified value.
`UTF8CodepointSize`	function	Returns the size of the UTF-8 codepoint in bytes.
`UTF8CodepointSizeFast`	function	Fast version of UTF8CodepointSize.
`UTF8CodepointStart`	function	Finds the n-th UTF-8 codepoint.
`UTF8CodepointStrictSize`	function	Gets the number of bytes needed for the UTF-8 codepoint.
`UTF8CodepointToByteIndex`	function	Finds the byte index of the n-th UTF-8 codepoint.
`UTF8CodepointToUnicode`	function	Converts a UTF-8-encoded character to its unique Unicode U+XXXX character value.
`UTF8CompareStr`	function	Compares the UTF-8-encoded string values.
`UTF8CompareStrP`	function	Compares the specified PChar values.
`UTF8CompareText`	function	Case-insensitive comparison of two UTF-8-encoded values.
`UTF8CompareTextP`	function	Performs a case-insensitive comparision for the specified UTF-8-encoded PChar values.
`UTF8Copy`	function	Copies the specified number of codepoints from the UTF-8-encoded string starting at the specified character index.
`UTF8CStringToUTF8String`	function	Copies from a C-style string with UTF-8 encoding to UTF-8 string.
`UTF8Delete`	procedure	Deletes characters (or codepoints) in a UTF-8-encoded string.
`UTF8EndsText`	function	Determines if a string ends with the specified value.
`Utf8EscapeControlChars`	function	Translates control characters in a UTF-8-encoded string into human-readable escaped format.
`UTF8FindNearestCharStart`	function	Finds the start of the UTF-8 character at the specified position.
`UTF8FixBroken`	procedure	Replaces all invalid UTF-8 characters in a string with the specified character.
`UTF8Insert`	procedure	Inserts the specified UTF-8 values into a string at the specified character position.
`UTF8LeftStr`	function	Gets the specified number of characters (codepoints) at the start of the string.
`UTF8Length`	function	Gets the length of a UTF-8-encoded string in codepoints.
`UTF8LengthFast`	function	Fast version of UTF8Length.
`UTF8LowerCase`	function	Converts the specified string to lowercase using Unicode case mapping rules.
`UTF8LowerCaseFast`	function	Gets the lowercase value for the specified text. Optimized to improve speed for ASCII content in the argument.
`UTF8LowerString`	function	Converts the specified string to lowercase using Unicode case mapping rules.
`UTF8PadCenter`	function	Center aligns a string to the specified length.
`UTF8PadLeft`	function	Adds the specified number of values in AUtf8Char to the beginning of a string.
`UTF8PadRight`	function	Appends the specified number of UTF-8 codepoints to the end of a string.
`UTF8Pos`	function	Returns the character index where the search text starts in the string.
`UTF8PosP`	function	Returns a pointer to the position where SearchForText starts in SearchInText, or Nil when not found.
`UTF8ProperCase`	function	Capitalizes the first letter of each word in the UTF-8-encoded string.
`UTF8QuotedStr`	function	Performs safe quoting for the specified UTF-8-encoded string value.
`UTF8ReverseString`	function	Reverses the order of codepoints in the specified string.
`UTF8RightStr`	function	Gets the specified number of characters (codepoints) at the end of the string.
`UTF8RPos`	function	Gets the right-most position in the Source string for the value in Substr.
`UTF8StartsText`	function	Determines if a string starts with the specified value.
`UTF8StringOfChar`	function	Creates a string filled with the specified number of given codepoints.
`UTF8StringReplace`	function	Replaces one or more values in a UTF-8-encoded string which match a given pattern.
`UTF8SwapCase`	function	Converts the case for UTF-8 codepoints in the specified string and returns the converted value.
`UTF8ToConsole`	function	Converts a UTF-8-encoded string to console (OEM) encoding.
`UTF8ToDoubleByte`	function	Converts a UTF-8-encode string to its DBCS representation.
`UTF8ToDoubleByteString`	function	Converts UTF-8 values to their DBCS equivalent.
`UTF8ToSys`	function	Ensures UTF-8 characters (or format settings) are converted to the system code page.
`UTF8ToUTF16`	function	Converts the UTF-8 encoded string to UTF-16 encoding (system endian).
`UTF8ToWinCP`	function	Converts the UTF-8-encoded string to the Windows code page encoding.
`UTF8Trim`	function	Removes leading and trailing whitespace or control characters.
`Utf8TryFindCodepointStart`	function	Tries to find the start of a valid UTF-8 codepoint in a string.
`UTF8UpperCase`	function	Converts the specified string to uppercase using Unicode case mapping rules.
`UTF8UpperCaseFast`	function	Gets the uppercase value for the specified text. Optimized to improve speed for ASCII content in the argument.
`UTF8UpperString`	function	Inline variant of UTF8UpperCase.
`UTF8WrapText`	function	Creates a word-wrapped version of the specified string.
`WinCPToUTF8`	function	Converts the string from Windows code page to UTF-8.

Types

`PEscapedStrings`	type	Pointer to a TEscapedStrings type.
`TControlChars`	type	Specifies a range used to identify control characters.
`TConvertOption`	enumeration	Indicates options enabled during UTF-8 <-> UTF-16 conversions.
`TConvertOptions`	set	Stores values from the TConvertOption enumeration.
`TConvertResult`	enumeration	Indicates the result from UTF-8 <-> UTF-16 conversions.
`TEscapedStrings`	type	Fixed-length array of strings used to convert control characters to an escaped encoding style.
`TEscapeMode`	enumeration	Represents styles used to escape control characters.
`TUTF8TrimFlag`	enumeration	Controls trimming actions performed in UTF8Trim.
`TUTF8TrimFlags`	set	Stores values from the TUTF8TrimFlag enumeration.

Constants

trNoError constant Deprecated. Use trSuccess in TConvertResult instead.

Variables

FPUpChars variable Contains uppercase characters for all values in the char type.

Uses

cwstring
FPCAdds
Classes
SysUtils
StrUtils

An experiment, built from Lazarus main 2dfa93c66e of 10-22-2026. Not the official Lazarus documentation.