int chartorune(Rune *r, char *s)

int runelen(long r)

int fullrune(char *s, int n)

int utflen(char *s)

char* utfrune(char *s, long c)

char* utfrrune(char *s, long c)

char* utfutf(char *s1, char *s2)

Runetochar copies one rune at r to at most UTFmax bytes starting at s and returns the number of bytes copied. UTFmax, defined as 3 in <libc.h>, is the maximum number of bytes required to represent a rune.

Chartorune copies at most UTFmax bytes starting at s to one rune at r and returns the number of bytes copied. If the input is not exactly in UTF format, chartorune will convert to 0x80 and return 1.

Runelen returns the number of bytes required to convert r into UTF.

Fullrune returns 1 if the string s of length n is long enough to be decoded by chartorune and 0 otherwise. This does not guarantee that the string contains a legal UTF encoding. This routine is used by programs that obtain input a byte at a time and need to know when a full rune has arrived.

The following routines are analogous to the corresponding string routines with utf substituted for str and rune substituted for chr.

Utflen returns the number of runes that are represented by the UTF string s.

Utfrune (utfrrune) returns a pointer to the first (last) occurrence of rune c in the UTF string s, or 0 if c does not occur in the string. The NUL byte terminating a string is considered to be part of the string s.

Utfutf returns a pointer to the first occurrence of the UTF string s2 as a UTF substring of s1, or 0 if there is none. If s2 is the null string, utfutf returns s1.