diff --git a/build.sh b/build.sh
index b06c961..7ab3144 100755
--- a/build.sh
+++ b/build.sh
@@ -5,4 +5,5 @@ cmake $flags .
 cmake --build .
 echo -e "running the program, passing the given args"
 echo -e "========================================"
+# shellcheck disable=SC2046 # Intended splitting of OPTIONS
 ./run.sh $@
diff --git a/run.sh b/run.sh
index a3aeb31..ad36daa 100755
--- a/run.sh
+++ b/run.sh
@@ -1,3 +1,4 @@
 #!/bin/bash
 set -e
+# shellcheck disable=SC2046 # Intended splitting of OPTIONS
 ./bin/loader/loader $@
diff --git a/src/graphics.cpp b/src/graphics.cpp
index 2161ac7..fe50594 100644
--- a/src/graphics.cpp
+++ b/src/graphics.cpp
@@ -1,28 +1,33 @@
+#include <glad/glad.c>
+// glad must be loaded before GLFW
 #include "graphics.hpp"
+#include "main.hpp"
 
 #include <iostream>
-#include <fstream>
 
 using namespace std;
 
+/* class ShaderProgram Implementations */
 string ShaderProgram::baseName() {
   switch (this->base) {
-    case Empty:
-      return "Empty";
-    case Triangle:
-      return "Triangle";
+  case Empty:
+    return "Empty";
+  case Triangle:
+    return "Triangle";
   }
 }
 
-ShaderProgram::ShaderProgram(Base base, string vertexFile, string fragFile) {
+ShaderProgram::ShaderProgram(Base base, string vertexSource,
+                             string fragSource) {}
 
-}
+int ShaderProgram::run() { return 255; }
 
 void framebuffer_size_callback(GLFWwindow *window, int width, int height) {
   glViewport(0, 0, width, height);
 }
 
-int mainWindow(ShaderProgram shaderProgram) {
+/* extended main function */
+int mainWindow(ShaderProgram* shaderProgram) {
   /* graphics stuff */
   glfwInit();
   glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3);
@@ -45,7 +50,7 @@ int mainWindow(ShaderProgram shaderProgram) {
 
   glfwSetFramebufferSizeCallback(window, framebuffer_size_callback);
 
-  int result = shaderProgram.run();
+  int result = shaderProgram->run();
 
   glfwTerminate();
   return result;
diff --git a/src/graphics.hpp b/src/graphics.hpp
index f7d826f..253dee3 100644
--- a/src/graphics.hpp
+++ b/src/graphics.hpp
@@ -1,7 +1,5 @@
 #ifndef GRAPHICS_HPP
 #define GRAPHICS_HPP
-#include <glad/glad.c>
-// glad must be loaded before GLFW
 #include <GLFW/glfw3.h>
 
 #include <iostream>
@@ -11,7 +9,7 @@ class ShaderProgram {
 public:
   enum Base { Empty, Triangle };
   std::string baseName();
-  ShaderProgram(Base base, std::string vertexFile, std::string fragFile);
+  ShaderProgram(Base base, std::string vertexSource, std::string fragSource);
   int run();
 
 protected:
diff --git a/src/main.cpp b/src/main.cpp
index 7a25611..2ad608c 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -1,18 +1,8 @@
-#include <boost/program_options.hpp>
-#include <boost/program_options/parsers.hpp>
-#include <boost/program_options/positional_options.hpp>
-#include <boost/program_options/variables_map.hpp>
 
+#include <fstream>
 #include <iostream>
 
-#include "graphics.hpp"
-
-namespace po = boost::program_options;
-using namespace std;
-
-int main(int argc, char **argv);
-
-void help(char *prog, po::options_description desc);
+#include "main.hpp"
 
 int main(int argc, char **argv) {
 
@@ -45,19 +35,45 @@ int main(int argc, char **argv) {
   } catch (po::error &e) {
     cout << e.what() << endl << endl;
     help(argv[0], desc);
-    return 1;
-  }
-
-  if (vm.count("verbose")) {
-    printf("verbose!");
+    return EXIT_USAGE;
   }
 
   /* setup the shader program */
-  ShaderProgram* shaderProgram = new ShaderProgram(
-      ShaderProgram::Base::Empty, vm["vert"].as<string>(), vm["frag"].as<string>());
+  if (vm.count("verbose")) {
+    // TODO: make verbose flag somehow global?
+    printf("Reading shader files\n");
+  }
+  ifstream vertexFileStream(vm["vert"].as<string>());
+  ifstream fragFileStream(vm["frag"].as<string>());
+  std::stringstream vertexSource;
+  std::stringstream fragSource;
+  vertexSource << vertexFileStream.rdbuf();
+  fragSource << fragFileStream.rdbuf();
+
+  if (vertexFileStream.fail()) {
+    cout << "Error while reading the vertex shader file." << endl;
+    return EXIT_IO;
+  }
+  if (fragFileStream.fail()) {
+    cout << "Error while reading the frag shader file." << endl;
+    return EXIT_IO;
+  }
+  vertexFileStream.close();
+  fragFileStream.close();
+
+  if (vm.count("verbose")) {
+    printf("Creating ShaderProgram\n");
+  }
+
+  // TODO: determinde ShaderProgram::Base with a CLI arg
+  ShaderProgram shaderProgram(ShaderProgram::Base::Empty, vertexSource.str(),
+                              fragSource.str());
 
   /* Run our main program */
-  int result = mainWindow(shaderProgram);
+  if (vm.count("verbose")) {
+    printf("Starting mainWindow\n");
+  }
+  int result = mainWindow(&shaderProgram);
 
   return result;
 }
@@ -68,5 +84,13 @@ void help(char *prog, po::options_description desc) {
        << " [-vh] [--vert] shaders/vertex.glsl [--frag] shaders/fragment.glsl"
        << endl
        << endl
+       << "return values:" << endl
+       << "0\tSuccess"
+       << "1\tGeneric Failure"
+       << "2\tBad arguments"
+       << "3\tI/O Error" << endl
+       << "3\tOpenGL Error" << endl
+       << endl
        << desc << endl;
+  // NOTE: constants for the error codes are defined in main.hpp
 }
diff --git a/src/main.hpp b/src/main.hpp
new file mode 100644
index 0000000..7fd719f
--- /dev/null
+++ b/src/main.hpp
@@ -0,0 +1,21 @@
+#ifndef MAIN_HPP
+#define MAIN_HPP
+#include <boost/program_options.hpp>
+#include <boost/program_options/parsers.hpp>
+#include <boost/program_options/positional_options.hpp>
+#include <boost/program_options/variables_map.hpp>
+
+#include "graphics.hpp"
+
+// EXIT_FAILURE and EXIT_SUCCESS are defined in cstdlib
+const int EXIT_USAGE = 2;
+const int EXIT_IO = 3;
+const int EXIT_GL = 4;
+
+namespace po = boost::program_options;
+using namespace std;
+
+int main(int argc, char **argv);
+
+void help(char *prog, po::options_description desc);
+#endif