1 /* 2 * charset conversion utils 3 * 4 * Copyright (c) 2017 Rob Clark 5 * 6 * SPDX-License-Identifier: GPL-2.0+ 7 */ 8 9 #ifndef __CHARSET_H_ 10 #define __CHARSET_H_ 11 12 #define MAX_UTF8_PER_UTF16 3 13 14 /** 15 * utf16_strlen() - Get the length of an utf16 string 16 * 17 * Returns the number of 16 bit characters in an utf16 string, not 18 * including the terminating NULL character. 19 * 20 * @in the string to measure 21 * @return the string length 22 */ 23 size_t utf16_strlen(const uint16_t *in); 24 25 /** 26 * utf16_strnlen() - Get the length of a fixed-size utf16 string. 27 * 28 * Returns the number of 16 bit characters in an utf16 string, 29 * not including the terminating NULL character, but at most 30 * 'count' number of characters. In doing this, utf16_strnlen() 31 * looks at only the first 'count' characters. 32 * 33 * @in the string to measure 34 * @count the maximum number of characters to count 35 * @return the string length, up to a maximum of 'count' 36 */ 37 size_t utf16_strnlen(const uint16_t *in, size_t count); 38 39 /** 40 * utf16_strcpy() - UTF16 equivalent of strcpy() 41 */ 42 uint16_t *utf16_strcpy(uint16_t *dest, const uint16_t *src); 43 44 /** 45 * utf16_strdup() - UTF16 equivalent of strdup() 46 */ 47 uint16_t *utf16_strdup(const uint16_t *s); 48 49 /** 50 * utf16_to_utf8() - Convert an utf16 string to utf8 51 * 52 * Converts 'size' characters of the utf16 string 'src' to utf8 53 * written to the 'dest' buffer. 54 * 55 * NOTE that a single utf16 character can generate up to 3 utf8 56 * characters. See MAX_UTF8_PER_UTF16. 57 * 58 * @dest the destination buffer to write the utf8 characters 59 * @src the source utf16 string 60 * @size the number of utf16 characters to convert 61 * @return the pointer to the first unwritten byte in 'dest' 62 */ 63 uint8_t *utf16_to_utf8(uint8_t *dest, const uint16_t *src, size_t size); 64 65 #endif /* __CHARSET_H_ */ 66