ref: c96fb5471a7dc83f0acd53e1f15da589ea13280a
dir: /sys/src/libc/port/strspn.c/
#include <u.h> #include <libc.h> #define N 256 long strspn(char *s, char *b) { char map[N], *os; memset(map, 0, N); while(*b) map[*(uchar *)b++] = 1; os = s; while(map[*(uchar *)s++]) ; return s - os - 1; }