string add indexOf and lastIndexOf function

[jsbxyyx]

op string function

string indexOf(string str, string substr, int fromIndex)

string lastIndexOf(string str, string substr, int fromIndex)

[tezc]

probably you can do it with strstr(), no? something like strstr(str + fromIndex, substr)

[jsbxyyx]

int indexOf(string str, string substr, int fromIndex)

int lastIndexOf(string str, string substr, int fromIndex)

I'm describe error. return value type is int.

[tezc]

/* Returns a pointer to the beginning of the located substring.
   Returns NULL if the substring is not found or 'fromIndex' is larger than the length of str */
char *sc_str_indexof(const char *str, const char *needle, uint32_t fromIndex, int reverse);

maybe we can do something like this, similar to strstr(), it may return located string position.