strlcpy.cpp
size_t strlcpy(
char *dst,
const
char *src, size_t siz )
{
char* d = dst;
const char* s = src;
size_t n = siz;
if (s == 0 || d == 0) return 0;
/* Copy as many bytes as will fit */
if (n != 0 && --n != 0)
{
do
{
if ((*d++ = *s++) == 0)
break;
} while (--n != 0);
}
/* Not enough room in dst, add NUL and traverse rest of src */
if (n == 0)
{
if (siz != 0)
*d = '\0'; /* NUL-terminate dst */
while (*s++)
;
}
return(s - src - 1); /* count does not include NUL */
}
strlcat.cpp
size_t strlcat(
char* dst,
const
char* src, size_t siz )
{
char* d = dst;
const char* s = src;
size_t n = siz;
size_t dlen;
if (s == 0 || d == 0) return 0;
while (n-- != 0 && *d != '\0')
{
d++;
}
dlen = d - dst;
n = siz - dlen;
if (n == 0)
{
return(dlen + strlen(s));
}
while (*s != '\0')
{
if (n != 1)
{
*d++ = *s;
n--;
}
s++;
}
*d = '\0';
return(dlen + (s - src));
}
略作了修改,增加了对空指针的判断.
size_t strlcpy(
char *dst,
const
char *src, size_t siz )
{ char* d = dst; const char* s = src; size_t n = siz; if (s == 0 || d == 0) return 0; /* Copy as many bytes as will fit */ if (n != 0 && --n != 0) { do { if ((*d++ = *s++) == 0) break; } while (--n != 0); } /* Not enough room in dst, add NUL and traverse rest of src */ if (n == 0) { if (siz != 0) *d = '\0'; /* NUL-terminate dst */ while (*s++) ; } return(s - src - 1); /* count does not include NUL */}
strlcat.cpp
size_t strlcat(
char* dst,
const
char* src, size_t siz )
{ char* d = dst; const char* s = src; size_t n = siz; size_t dlen; if (s == 0 || d == 0) return 0; while (n-- != 0 && *d != '\0') { d++; } dlen = d - dst; n = siz - dlen; if (n == 0) { return(dlen + strlen(s)); } while (*s != '\0') { if (n != 1) { *d++ = *s; n--; } s++; } *d = '\0'; return(dlen + (s - src));}
略作了修改,增加了对空指针的判断.
