diff --git a/buffer.hpp b/buffer.hpp
index 8e48592..df2fb52 100644
--- a/buffer.hpp
+++ b/buffer.hpp
@@ -20,6 +20,10 @@ private:
     }
 
 public:
+    // so that i can create a  vecotr of set size, without the .reserve(), and other stuff
+    SubBuffer()
+    {
+    }
     // for std::sort support
     using iterator = Record*;
     iterator begin() { return data_; }
diff --git a/main.cpp b/main.cpp
index f621e2c..e833509 100644
--- a/main.cpp
+++ b/main.cpp
@@ -1,5 +1,6 @@
 #include "config.hpp"
 #include "record.hpp"
+#include "sort.cpp"
 #include "writer.hpp"
 #include <fstream>
 #include <iostream>
@@ -17,13 +18,6 @@ void generate_file(int N, const std::string& filename)
     }
 }
 
-int sort_file(const Configuration& opts)
-{
-    // TODO: Implement sorting with new buffer classes
-    std::cout << "Sorting not yet implemented\n";
-    return 0;
-}
-
 int main(int argc, char** argv)
 {
     try {
diff --git a/makefile b/makefile
index 6f37da3..0446cba 100644
--- a/makefile
+++ b/makefile
@@ -1,15 +1,15 @@
 CFLAGS = -g -lc++ -std=c++17
 
-build/main: main.cpp build
+build/main: main.cpp sort.cpp buffer.hpp reader.hpp writer.hpp build
 	clang $(CFLAGS) main.cpp -o build/main
 
 build:
 	mkdir -p build
 
-build/run: build
+build/run:
 	mkdir -p build/run
 
-build/run/tmp: build/run
+build/run/tmp:
 	mkdir -p build/run/tmp
 
 clean:
@@ -17,11 +17,12 @@ clean:
 
 generate: build/run/1.in
 
-build/run/1.in: build/run build/main
+# actually should depend on build/main and build/run, but that will trigger it every recompile, and i don't need that
+build/run/1.in: build/run/tmp
 	build/main -g -o build/run/1.in
 
 run: build/main build/run/1.in build/run/tmp
-	build/main -i build/run/1.in -d build/run/tmp | less
+	build/main -i build/run/1.in -d build/run/tmp
 
 debug: build/main tests/1.in
 	lldb -- build/main
diff --git a/reader.hpp b/reader.hpp
index c9432fb..2c69b3e 100644
--- a/reader.hpp
+++ b/reader.hpp
@@ -1,3 +1,4 @@
+// #todo maybe overload >> operators insted of read()
 #pragma once
 #include "record.hpp"
 #include <istream>
@@ -16,16 +17,21 @@ private:
     // returns true if at least one record was returned
     bool refill_buffer()
     {
+        std::cout << "refilling buffer\n";
         last_element_idx = -1;
         current_idx = 0;
 
         for (size_t i = 0; i < buffer_size; i++) {
+            std::cout << "buffer refill: i: " << i << '\n';
             if (!(input_stream >> read_buffer[i])) {
+                std::cout << "input stream error\n";
+                std::cout << read_buffer[i] << '\n';
                 break;
             }
-            last_element_idx = static_cast<int>(i);
+            last_element_idx = i;
         }
 
+        std::cout << "buffer refill successfull\n";
         return last_element_idx >= 0;
     }
 
diff --git a/sort.cpp b/sort.cpp
new file mode 100644
index 0000000..8e8fdec
--- /dev/null
+++ b/sort.cpp
@@ -0,0 +1,55 @@
+#pragma once
+#include "buffer.hpp"
+#include "config.hpp"
+#include "reader.hpp"
+#include "writer.hpp"
+#include <fstream>
+//
+// returns amount of records read
+size_t read_chunk(Reader& reader, SubBuffer& buff)
+{
+    for (size_t i = 0; i < buff.size(); i++) {
+        std::optional<Record> in = reader.read();
+        if (!in.has_value()) {
+            return i;
+        }
+        buff[i] = in.value();
+    }
+    return buff.size();
+}
+
+void write_to_file(const std::string& filename, SubBuffer& buff, size_t n)
+{
+    std::ofstream out_stream(filename);
+    Writer output_writer(out_stream);
+    for (size_t j = 0; j < n; j++) {
+        output_writer.write(buff[j]);
+    }
+}
+
+void create_initial_runs(const std::string& input_filename, const std::string& directory, Buffer& main_buffer)
+{
+    auto buff = main_buffer.divide(1)[0];
+
+    std::ifstream in_stream(input_filename, std::ios::binary);
+    Reader input_reader(in_stream);
+    for (size_t run_index = 0;; run_index++) {
+        std::cout << "creating run " << run_index << '\n';
+        size_t size = read_chunk(input_reader, buff);
+        std::cout << "read " << size << " records\n";
+        if (size == 0) {
+            break;
+        }
+        std::sort(buff.begin(), buff.begin() + size);
+        write_to_file(directory + "/" + std::to_string(run_index) + ".run", buff, size);
+    }
+}
+
+int sort_file(const Configuration& opts)
+{
+    Buffer main_buffer(opts.n * opts.b);
+    create_initial_runs(opts.input_file, opts.directory, main_buffer);
+    // TODO: Implement sorting with new buffer classes
+    std::cout << "Sorting not yet implemented\n";
+    return 0;
+}
diff --git a/writer.hpp b/writer.hpp
index 149b71e..28e089d 100644
--- a/writer.hpp
+++ b/writer.hpp
@@ -1,3 +1,4 @@
+// #todo maybe overload << operators insted of write()
 #pragma once
 #include "record.hpp"
 #include <ostream>
@@ -17,7 +18,7 @@ private:
     bool flush_buffer()
     {
         for (size_t i = 0; i < current_index; ++i) {
-            if (!(output_stream << write_buffer[i])) {
+            if (!(output_stream << write_buffer[i] << " ")) {
                 return false;
             }
         }