|
NAME
| |
runetochar, chartorune, runelen, runenlen, fullrune, utfecpy,
utflen, utfnlen, utfrune, utfrrune, utfutf – rune/UTF conversion
|
SYNOPSIS
| |
#include <u.h>
#include <libc.h>
int runetochar(char *s, Rune *r)
int chartorune(Rune *r, char *s)
int runelen(long r)
int runenlen(Rune *r, int n)
int fullrune(char *s, int n)
char* utfecpy(char *s1, char *es1, char *s2)
int utflen(char *s)
int utfnlen(char *s, long n)
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 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 Runeerror (0xFFFD)
and return 1.
Runelen returns the number of bytes required to convert r into
UTF.
Runenlen returns the number of bytes required to convert the n
runes pointed to by 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.
Utfecpy copies UTF sequences until a null sequence has been copied,
but writes no sequences beyond es1. If any sequences are copied,
s1 is terminated by a null sequence, and a pointer to that sequence
is returned. Otherwise, the original s1 is returned.
Utflen returns the number of runes that are represented by the
UTF string s.
Utfnlen returns the number of complete runes that are represented
by the first n bytes of UTF string s. If the last few bytes of
the string contain an incompletely coded rune, utfnlen will not
count them; in this way, it differs from utflen, which includes
every byte of the string.
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.
|
SOURCE
SEE ALSO
|
|
