📚 utf8_decoder

A simple one header solution to decode hex utf8 string in C and C++.

Usage

Just #include "utf8_decoder.h" in your code!

The current supported platforms are Linux, macOS and Windows.

The current supported compilers are GCC, CLANG, MSVC.

API function docs

char hexchr_to_hex(const char hex_chr);

Return a char decimal value greater than or equal to zero and less than zero if char is out of range

Convert hexadecimal char beetwen '0' - 'F' ('a'-'z' & 'A'-'Z') in decimal value

Utf8Type utf8type(const char* hex_str, int32_t* cdp);

Return the Utf8Type

But you can get codepoint (decimal value) of hexadecimal string if you pass an int32_t pointer instead of NULL

Convert hexadecimal string in a decimal value, and determinate what is the range of utf8 string

void utf8decode(const char* hex_str, char* dest);

Convert hexadecimal utf8 string into usable utf8 string and store it in dest

dest will be empty if hexadecimal string is invalid or out of range

NB: min size of dest must be 2 and max 5 with null char

bool utf8valid(const char* str);

Return a bool (true, if valid and false otherwise)

Check if str is a valid utf8 string

int32_t utf8codepoint(const char* str);

Return codepoint greater than or equal to zero and less than zero if char is out of range or if string is NULL

Convert utf8 string in codepoint (decimal value)

void utf8chr(const int32_t codepoint, char* dest);

Convert codepoint into usable utf8 string and store it in dest

dest will be empty if hexadecimal string is invalid or out of range

NB: min size of dest must be 2 and max 5 with null char

Example

#include <stdio.h>
#include "utf8_decoder.h"

int main()
{
    char dst1[5];
    char dst2[5];
    int codepoint;

    // one byte
    utf8decode("0024", dst1);
    printf("decoded result : %s\n", dst1); // decoded : $
    codepoint = utf8codepoint(dst1);
    printf("decoded codepoint : %d\n", codepoint); // codepoint : 36
    utf8chr(codepoint, dst2);
    printf("chr codepoint : %s\n", dst2); // decoded : $

    // two byte
    utf8decode("00A2", dst1);
    printf("decoded result : %s\n", dst1); // decoded : ¢
    codepoint = utf8codepoint(dst1);
    printf("decoded codepoint : %d\n", codepoint); // codepoint : 162
    utf8chr(codepoint, dst2);
    printf("chr codepoint : %s\n", dst2); // decoded : ¢

    // three byte
    utf8decode("D55C", dst1);
    printf("decoded result : %s\n", dst1); // decoded : 한
    codepoint = utf8codepoint(dst1);
    printf("decoded codepoint : %d\n", codepoint); // codepoint : 54620
    utf8chr(codepoint, dst2);
    printf("chr codepoint : %s\n", dst2); // decoded : 한

    // four byte
    utf8decode("1F47A", dst1);
    printf("decoded result : %s\n", dst1); // decoded : 👺
    codepoint = utf8codepoint(dst1);
    printf("decoded codepoint : %d\n", codepoint); // codepoint : 128122
    utf8chr(codepoint, dst2);
    printf("chr codepoint : %s\n", dst2); // decoded : 👺

    return 0;

}

NB : the utf8valid function is based on the function of the same name in the utf8.h repository.