RUNE(3)

NAME
runetochar, chartorune, runelen, fullrune, utflen, utfrune, utfrrune, utfutf - rune/UTF conversion

SYNOPSIS
#include <libc.h>
int	runetochar(char *s, Rune *r)

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)

DESCRIPTION
These routines convert to and from a UTF byte stream and runes.

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

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

Runelen returns the number of characters 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 character 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 character 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.

SEE ALSO
utf(4)