9 * UTF-8 utility functions
11 * (c) 2010-2019 Steve Bennett <steveb@workware.net.au>
13 * See utf8.c for licence details.
19 #define MAX_UTF8_LEN 1
21 /* No utf-8 support. 1 byte = 1 char */
22 #define utf8_strlen(S, B) ((B) < 0 ? (int)strlen(S) : (B))
23 #define utf8_strwidth(S, B) utf8_strlen((S), (B))
24 #define utf8_tounicode(S, CP) (*(CP) = (unsigned char)*(S), 1)
25 #define utf8_index(C, I) (I)
26 #define utf8_charlen(C) 1
27 #define utf8_width(C) 1
31 #define MAX_UTF8_LEN 4
34 * Converts the given unicode codepoint (0 - 0x1fffff) to utf-8
35 * and stores the result at 'p'.
37 * Returns the number of utf-8 characters
39 int utf8_fromunicode(char *p, unsigned uc);
42 * Returns the length of the utf-8 sequence starting with 'c'.
44 * Returns 1-4, or -1 if this is not a valid start byte.
46 * Note that charlen=4 is not supported by the rest of the API.
48 int utf8_charlen(int c);
51 * Returns the number of characters in the utf-8
52 * string of the given byte length.
54 * Any bytes which are not part of an valid utf-8
55 * sequence are treated as individual characters.
57 * The string *must* be null terminated.
59 * Does not support unicode code points > \u1fffff
61 int utf8_strlen(const char *str, int bytelen);
64 * Calculates the display width of the first 'charlen' characters in 'str'.
67 int utf8_strwidth(const char *str, int charlen);
70 * Returns the byte index of the given character in the utf-8 string.
72 * The string *must* be null terminated.
74 * This will return the byte length of a utf-8 string
75 * if given the char length.
77 int utf8_index(const char *str, int charindex);
80 * Returns the unicode codepoint corresponding to the
81 * utf-8 sequence 'str'.
83 * Stores the result in *uc and returns the number of bytes
86 * If 'str' is null terminated, then an invalid utf-8 sequence
87 * at the end of the string will be returned as individual bytes.
89 * If it is not null terminated, the length *must* be checked first.
91 * Does not support unicode code points > \u1fffff
93 int utf8_tounicode(const char *str, int *uc);
96 * Returns the width (in characters) of the given unicode codepoint.
97 * This is 1 for normal letters and 0 for combining characters and 2 for wide characters.
99 int utf8_width(int ch);