src/lib9/utf/utfecpy.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.
 */
#define _BSD_SOURCE 1	/* memccpy */
#include <stdarg.h>
#include <string.h>
#include "plan9.h"
#include "utf.h"

char*
utfecpy(char *to, char *e, char *from)
{
	char *end;

	if(to >= e)
		return to;
	end = memccpy(to, from, '\0', e - to);
	if(end == nil){
		end = e-1;
		while(end>to && (*--end&0xC0)==0x80)
			;
		*end = '\0';
	}else{
		end--;
	}
	return end;
}