Minor improvements to the string-related functions.

libc/inc/string.h

@@ -173,11 +173,11 @@ char *strtok_r(char *str, const char *delim, char **saveptr);
 /// @brief Parses the string using the separator, and at each call it saves the
 /// parsed token in buffer. The pointer `string` will be modified.
 /// @param string cursor used to parse the string, it will be modified.
-/// @param separator the separator we are using.
+/// @param separators the list of separators we are using.
 /// @param buffer the buffer where we save the parsed token.
 /// @param buflen the length of the buffer.
 /// @return 1 if we still have things to parse, 0 if we finished parsing.
-int tokenize(char **string, char separator, char *buffer, ssize_t buflen);
+int tokenize(char *string, char *separators, size_t *offset, char *buffer, ssize_t buflen);
 
 /// @brief Copies the values of num bytes from the location pointed by source
 /// to the memory block pointed by destination.