blob: a0c617bd7cdb7d2f0a75476e9f0ac3a86149aa70 (
plain) (
blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
#include <string.h>
#define BITOP(a,b,op) \
((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a))))
size_t strcspn(const char *s, const char *c)
{
const char *a = s;
size_t byteset[32/sizeof(size_t)];
if (!c[0] || !c[1]) return __strchrnul(s, *c)-a;
memset(byteset, 0, sizeof byteset);
for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++);
for (; *s && !BITOP(byteset, *(unsigned char *)s, &); s++);
return s-a;
}
|