From 0b44a0315b47dd8eced9f3b7f31580cf14bbfc01 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Sat, 12 Feb 2011 00:22:29 -0500 Subject: initial check-in, version 0.5.0 --- src/string/strcspn.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) create mode 100644 src/string/strcspn.c (limited to 'src/string/strcspn.c') diff --git a/src/string/strcspn.c b/src/string/strcspn.c new file mode 100644 index 00000000..439b7be4 --- /dev/null +++ b/src/string/strcspn.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 strcspn(const char *_s, const char *_c) +{ + const unsigned char *s = _s; + const unsigned char *c = _c; + const unsigned 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, *c, |=); c++); + for (; *s && !BITOP(byteset, *s, &); s++); + return s-a; +} -- cgit v1.2.1