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| | #include <string.h>
#include <stdlib.h>
#include <stdint.h>
#include <limits.h>
#include "libc.h"
#define ALIGN (sizeof(size_t)-1)
#define ONES ((size_t)-1/UCHAR_MAX)
#define HIGHS (ONES * (UCHAR_MAX/2+1))
#define HASZERO(x) ((x)-ONES & ~(x) & HIGHS)
size_t strlcpy(char *d, const char *s, size_t n)
{
char *d0 = d;
size_t *wd;
const size_t *ws;
if (!n--) goto finish;
if (((uintptr_t)s & ALIGN) == ((uintptr_t)d & ALIGN)) {
for (; ((uintptr_t)s & ALIGN) && n && (*d=*s); n--, s++, d++);
if (n && *s) {
wd=(void *)d; ws=(const void *)s;
for (; n>=sizeof(size_t) && !HASZERO(*ws);
n-=sizeof(size_t), ws++, wd++) *wd = *ws;
d=(void *)wd; s=(const void *)ws;
}
}
for (; n && (*d=*s); n--, s++, d++);
*d = 0;
finish:
return d-d0 + strlen(s);
}
|