string.c:3281
void
Init_String()
{
    rb_cString  = rb_define_class("String", rb_cObject);
    rb_include_module(rb_cString, rb_mComparable);
    rb_include_module(rb_cString, rb_mEnumerable);
    rb_define_alloc_func(rb_cString, str_alloc);
    rb_define_method(rb_cString, "initialize", rb_str_init, -1);
    rb_define_method(rb_cString, "initialize_copy", rb_str_replace, 1); 
    rb_define_method(rb_cString, "<=>", rb_str_cmp_m, 1);
    rb_define_method(rb_cString, "==", rb_str_equal, 1);
    rb_define_method(rb_cString, "eql?", rb_str_eql, 1);
    rb_define_method(rb_cString, "hash", rb_str_hash_m, 0);
    rb_define_method(rb_cString, "casecmp", rb_str_casecmp, 1);
    rb_define_method(rb_cString, "+", rb_str_plus, 1);
    rb_define_method(rb_cString, "*", rb_str_times, 1);
    rb_define_method(rb_cString, "%", rb_str_format, 1);
    rb_define_method(rb_cString, "[]", rb_str_aref_m, -1);
    rb_define_method(rb_cString, "[]=", rb_str_aset_m, -1);
    rb_define_method(rb_cString, "insert", rb_str_insert, 2);
    rb_define_method(rb_cString, "length", rb_str_length, 0);
    rb_define_method(rb_cString, "size", rb_str_length, 0);
    rb_define_method(rb_cString, "empty?", rb_str_empty, 0);
    rb_define_method(rb_cString, "=~", rb_str_match, 1);
    rb_define_method(rb_cString, "~", rb_str_match2, 0);
    rb_define_method(rb_cString, "match", rb_str_match_m, 1);
    rb_define_method(rb_cString, "succ", rb_str_succ, 0);
    rb_define_method(rb_cString, "succ!", rb_str_succ_bang, 0);
    rb_define_method(rb_cString, "next", rb_str_succ, 0);
    rb_define_method(rb_cString, "next!", rb_str_succ_bang, 0);
    rb_define_method(rb_cString, "upto", rb_str_upto_m, 1);
    rb_define_method(rb_cString, "index", rb_str_index_m, -1);
    rb_define_method(rb_cString, "rindex", rb_str_rindex_m, -1);
    rb_define_method(rb_cString, "replace", rb_str_replace, 1);

    rb_define_method(rb_cString, "to_i", rb_str_to_i, -1);
    rb_define_method(rb_cString, "to_f", rb_str_to_f, 0);
    rb_define_method(rb_cString, "to_s", rb_str_to_s, 0);
    rb_define_method(rb_cString, "to_str", rb_str_to_s, 0);
    rb_define_method(rb_cString, "inspect", rb_str_inspect, 0);
    rb_define_method(rb_cString, "dump", rb_str_dump, 0);

    rb_define_method(rb_cString, "upcase", rb_str_upcase, 0);
    rb_define_method(rb_cString, "downcase", rb_str_downcase, 0);
    rb_define_method(rb_cString, "capitalize", rb_str_capitalize, 0);
    rb_define_method(rb_cString, "swapcase", rb_str_swapcase, 0);

    rb_define_method(rb_cString, "upcase!", rb_str_upcase_bang, 0);
    rb_define_method(rb_cString, "downcase!", rb_str_downcase_bang, 0);
    rb_define_method(rb_cString, "capitalize!", rb_str_capitalize_bang, 0);
    rb_define_method(rb_cString, "swapcase!", rb_str_swapcase_bang, 0);

    rb_define_method(rb_cString, "hex", rb_str_hex, 0);
    rb_define_method(rb_cString, "oct", rb_str_oct, 0);
    rb_define_method(rb_cString, "split", rb_str_split_m, -1);
    rb_define_method(rb_cString, "reverse", rb_str_reverse, 0);
    rb_define_method(rb_cString, "reverse!", rb_str_reverse_bang, 0);
    rb_define_method(rb_cString, "concat", rb_str_concat, 1);
    rb_define_method(rb_cString, "<<", rb_str_concat, 1);
    rb_define_method(rb_cString, "crypt", rb_str_crypt, 1);
    rb_define_method(rb_cString, "intern", rb_str_intern, 0);
    rb_define_method(rb_cString, "to_sym", rb_str_intern, 0);

    rb_define_method(rb_cString, "include?", rb_str_include, 1);

    rb_define_method(rb_cString, "scan", rb_str_scan, 1);

    rb_define_method(rb_cString, "ljust", rb_str_ljust, -1);
    rb_define_method(rb_cString, "rjust", rb_str_rjust, -1);
    rb_define_method(rb_cString, "center", rb_str_center, -1);

    rb_define_method(rb_cString, "sub", rb_str_sub, -1);
    rb_define_method(rb_cString, "gsub", rb_str_gsub, -1);
    rb_define_method(rb_cString, "chop", rb_str_chop, 0);
    rb_define_method(rb_cString, "chomp", rb_str_chomp, -1);
    rb_define_method(rb_cString, "strip", rb_str_strip, 0);
    rb_define_method(rb_cString, "lstrip", rb_str_lstrip, 0);
    rb_define_method(rb_cString, "rstrip", rb_str_rstrip, 0);

    rb_define_method(rb_cString, "sub!", rb_str_sub_bang, -1);
    rb_define_method(rb_cString, "gsub!", rb_str_gsub_bang, -1);
    rb_define_method(rb_cString, "chop!", rb_str_chop_bang, 0);
    rb_define_method(rb_cString, "chomp!", rb_str_chomp_bang, -1);
    rb_define_method(rb_cString, "strip!", rb_str_strip_bang, 0);
    rb_define_method(rb_cString, "lstrip!", rb_str_lstrip_bang, 0);
    rb_define_method(rb_cString, "rstrip!", rb_str_rstrip_bang, 0);

    rb_define_method(rb_cString, "tr", rb_str_tr, 2);
    rb_define_method(rb_cString, "tr_s", rb_str_tr_s, 2);
    rb_define_method(rb_cString, "delete", rb_str_delete, -1);
    rb_define_method(rb_cString, "squeeze", rb_str_squeeze, -1);
    rb_define_method(rb_cString, "count", rb_str_count, -1);

    rb_define_method(rb_cString, "tr!", rb_str_tr_bang, 2);
    rb_define_method(rb_cString, "tr_s!", rb_str_tr_s_bang, 2);
    rb_define_method(rb_cString, "delete!", rb_str_delete_bang, -1);
    rb_define_method(rb_cString, "squeeze!", rb_str_squeeze_bang, -1);

    rb_define_method(rb_cString, "each_line", rb_str_each_line, -1);
    rb_define_method(rb_cString, "each", rb_str_each_line, -1);
    rb_define_method(rb_cString, "each_byte", rb_str_each_byte, 0);

    rb_define_method(rb_cString, "sum", rb_str_sum, -1);

    rb_define_global_function("sub", rb_f_sub, -1);
    rb_define_global_function("gsub", rb_f_gsub, -1);

    rb_define_global_function("sub!", rb_f_sub_bang, -1);
    rb_define_global_function("gsub!", rb_f_gsub_bang, -1);

    rb_define_global_function("chop", rb_f_chop, 0);
    rb_define_global_function("chop!", rb_f_chop_bang, 0);

    rb_define_global_function("chomp", rb_f_chomp, -1);
    rb_define_global_function("chomp!", rb_f_chomp_bang, -1);

    rb_define_global_function("split", rb_f_split, -1);
    rb_define_global_function("scan", rb_f_scan, 1);

    rb_define_method(rb_cString, "slice", rb_str_aref_m, -1);
    rb_define_method(rb_cString, "slice!", rb_str_slice_bang, -1);

    id_to_s = rb_intern("to_s");

    rb_fs = Qnil;
    rb_define_variable("$;", &rb_fs);
    rb_define_variable("$-F", &rb_fs);
}
