blob: c843ff97476aedb4821fc41091689bfc8652fea2 [file] [log] [blame]
#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]) return strlen(s);
if (!c[1]) return (s=strchr(s, *c)) ? s-a : strlen(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;
}