From 4abab5ad6c8465a7528ccdd5f49367da05f78bbd Mon Sep 17 00:00:00 2001 From: Vladimir Azarov Date: Tue, 1 Oct 2024 15:47:05 +0200 Subject: Initial version --- src/string/strspn.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 src/string/strspn.c (limited to 'src/string/strspn.c') diff --git a/src/string/strspn.c b/src/string/strspn.c new file mode 100644 index 0000000..9543dad --- /dev/null +++ b/src/string/strspn.c @@ -0,0 +1,20 @@ +#include + +#define BITOP(a,b,op) \ + ((a)[(size_t)(b)/(8*sizeof *(a))] op (size_t)1<<((size_t)(b)%(8*sizeof *(a)))) + +size_t strspn(const char *s, const char *c) +{ + const char *a = s; + size_t byteset[32/sizeof(size_t)] = { 0 }; + + if (!c[0]) return 0; + if (!c[1]) { + for (; *s == *c; s++); + return s-a; + } + + for (; *c && BITOP(byteset, *(unsigned char *)c, |=); c++); + for (; *s && BITOP(byteset, *(unsigned char *)s, &); s++); + return s-a; +} -- cgit v1.2.3