trampoline/lib/lib9/utf/utfrune.c

45 lines
1.2 KiB
C

/*
* The authors of this software are Rob Pike and Ken Thompson.
* Copyright (c) 2002 by Lucent Technologies.
* Permission to use, copy, modify, and distribute this software for any
* purpose without fee is hereby granted, provided that this entire notice
* is included in all copies of any software which is or includes a copy
* or modification of this software and in all copies of the supporting
* documentation for such software.
* THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR IMPLIED
* WARRANTY. IN PARTICULAR, NEITHER THE AUTHORS NOR LUCENT TECHNOLOGIES MAKE
* ANY REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE MERCHANTABILITY
* OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR PURPOSE.
*/
#include <stdarg.h>
#include <string.h>
#include "plan9.h"
#include "utf.h"
char*
utfrune(char *s, long c)
{
long c1;
Rune r;
int n;
if(c < Runesync) /* not part of utf sequence */
return strchr(s, c);
for(;;) {
c1 = *(uchar*)s;
if(c1 < Runeself) { /* one byte rune */
if(c1 == 0)
return 0;
if(c1 == c)
return s;
s++;
continue;
}
n = chartorune(&r, s);
if(r == c)
return s;
s += n;
}
}