Add build system scaffolding and libc headers

1 files changed, 40 insertions, 0 deletions

diff --git a/lib/libc/string/strtok.c b/lib/libc/string/strtok.c
new file mode 100644
index 00000000..33d0d685
--- /dev/null
+++ b/lib/libc/string/strtok.c
@@ -0,0 +1,40 @@
+#include <stddef.h>
+#include <string.h>
+
+char *strtok(char *restrict s, const char *restrict sep)
+{
+	static _Thread_local char *state = NULL;
+
+	if (s != NULL) {
+		state = s;
+	}
+
+	if (state == NULL) {
+		return NULL;
+	}
+
+	char *token = state;
+	while (*token && strchr(sep, *token)) {
+		token++;
+	}
+
+	if (*token == '\0') {
+		state = NULL;
+		return NULL;
+	}
+
+	char *start = token;
+
+	while (*token && strchr(sep, *token) == NULL) {
+		token++;
+	}
+
+	if (*token) {
+		*token = '\0';
+		state = token + 1;
+	} else {
+		state = NULL;
+	}
+
+	return start;
+}