Solution: The error was in my GLSL shader code, not the code I was using to compile the shaders. That being said, I also made changes to properly check for compilation and linking errors based on @Rabbid76 and @David Sullivan's responses.

Shader* createShader(char* vertexfile, char* fragmentfile) { const char* vertexcode = loadshader(vertexfile); unsigned int vertex = glCreateShader(GL_VERTEX_SHADER); glShaderSource(vertex, 1, &vertexcode, NULL); glCompileShader(vertex); { char log[1024]; int success; glGetShaderiv(vertex, GL_COMPILE_STATUS, &success); if (!success) { glGetShaderInfoLog(vertex, 1024, NULL, log); printf("Vertex Shader Failed to Compile!\n> OpenGL Error: %s\n", log); } } const char* fragmentcode = loadshader(fragmentfile); unsigned int fragment = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(fragment, 1, &fragmentcode, NULL); glCompileShader(fragment); { char log[1024]; int success; glGetShaderiv(fragment, GL_COMPILE_STATUS, &success); if (!success) { glGetShaderInfoLog(fragment, 1024, NULL, log); printf("Fragment Shader Failed to Compile!\n> OpenGL Error: %s\n", log); } } unsigned int data = glCreateProgram(); glAttachShader(data, vertex); glAttachShader(data, fragment); glLinkProgram(data); { char log[1024]; int success; glGetProgramiv(data, GL_LINK_STATUS, &success); if (!success) { glGetProgramInfoLog(data, 1024, NULL, log); printf("Shader Failed to Link!\n> OpenGL Error: %s", log); } } glDeleteShader(vertex); glDeleteShader(fragment); free((void*) vertexcode); free((void*) fragmentcode); Shader* shader = (Shader*) malloc(sizeof(Shader)); shader -> data = data; return shader; } 

#define GLEW_STATIC #include <GL/glew.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #define BUFFSIZE 1024 #define MAXSIZE 1048576 typedef struct Shader { unsigned int data; } Shader; char* loadshader(char*); Shader* createShader(char* vertexfile, char* fragmentfile) { char msg[512]; char log[512]; int success;  const char* vertexcode = loadshader(vertexfile); unsigned int vertex = glCreateShader(GL_VERTEX_SHADER); glShaderSource(vertex, 1, &vertexcode, NULL); glCompileShader(vertex); { glGetProgramiv(vertex, GL_LINK_STATUS, &success); if (!success) {   printf("Vertex File Name: %s\n", vertexfile); printf("Vertex Code: %d\n", vertexcode);  printf("Vertex Value: %d\n", vertex); glGetProgramInfoLog(vertex, 512, NULL, log);   printf(strcat(strcpy(msg, "Vertex Shader Failed to Compile!\n> OpenGL Error: "), log));  } } const char* fragmentcode = loadshader(fragmentfile); unsigned int fragment = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(fragment, 1, &fragmentcode, NULL); glCompileShader(fragment); { glGetProgramiv(fragment, GL_LINK_STATUS, &success); if (!success) { printf("\n\nFragment File Name: %s\n", fragmentfile); printf("Fragment Code: %d\n", fragmentcode);  printf("Fragment Value: %d\n", fragment); glGetProgramInfoLog(fragment, 512, NULL, log);   printf(strcat(strcpy(msg, "Fragment Shader Failed to Link!\n> OpenGL Error"), log));  } } unsigned int data = glCreateProgram(); glAttachShader(data, vertex); glAttachShader(data, fragment); glLinkProgram(data); { glGetProgramiv(data, GL_LINK_STATUS, &success); if (!success) {   printf("Program Value: %d\n", data); glGetProgramInfoLog(data, 512, NULL, log);   printf(strcat(strcpy(msg, "\n\nShader Program Failed to Link!\n> OpenGL Error: "), log)); } } glDeleteShader(vertex); glDeleteShader(fragment); free((void*) vertexcode); free((void*) fragmentcode); Shader* shader = (Shader*) malloc(sizeof(Shader)); shader -> data = data; return shader; } int main(int argc, char const *argv[]) { glewInit(); Shader* shader = createShader("data/test.vs", "data/test.fs"); printf("%s\n", shader ? "Shader Successfully Created!" : "Failed to Create Shader!"); return 0; } char* loadshader(char* filename) { FILE* file = fopen(filename, "r"); if (!file) return NULL; int flag = 0; char* shader = (char*) malloc(MAXSIZE); char* buffer = (char*) malloc(BUFFSIZE); while (fgets(buffer, BUFFSIZE, file) != NULL) strcat(shader, buffer); free(buffer); fclose(file); return shader; } 

Vertex File Name: data/test.vs Vertex Code: 81465408 Vertex Value: 1 Vertex Shader Failed to Compile! > OpenGL Error: ░☻ Fragment File Name: data/test.fs Fragment Code: 82587712 Fragment Value: 2 Fragment Shader Failed to Compile! > OpenGL Error: ░☻ [process exited with code 4294967295 (0xffffffff)] 

#define GLEW_STATIC #define NO_SDL_GLEXT #include <GL/glew.h> #include <SDL2/SDL.h> #include <SDL2/SDL_opengl.h> #include <stdio.h> #include <stdlib.h> #include <string.h> #define BUFFSIZE 1024 #define MAXSIZE 1048576 typedef struct Shader { unsigned int data; } Shader; char* loadshader(char*); Shader* createShader(char* vertexfile, char* fragmentfile) { const char* vertexcode = loadshader(vertexfile); unsigned int vertex = glCreateShader(GL_VERTEX_SHADER); glShaderSource(vertex, 1, &vertexcode, NULL); glCompileShader(vertex); {   char log[512]; int success; glGetProgramiv(vertex, GL_COMPILE_STATUS, &success); printf("Vertex File Name: %s\n", vertexfile); printf("Vertex Code: %d\n", vertexcode); printf("Vertex Value: %d\n", vertex);  glGetProgramInfoLog(vertex, 512, NULL, log); printf("Vertex Shader Failed to Compile!\n> OpenGL Error: %s\n\n - - - - - \n\n", log); } const char* fragmentcode = loadshader(fragmentfile); unsigned int fragment = glCreateShader(GL_FRAGMENT_SHADER); glShaderSource(fragment, 1, &fragmentcode, NULL); glCompileShader(fragment); { char log[512]; int success; glGetProgramiv(fragment, GL_COMPILE_STATUS, &success); printf("Fragment File Name: %s\n", fragmentfile); printf("Fragment Code: %d\n", fragmentcode); printf("Fragment Value: %d\n", fragment);  glGetProgramInfoLog(fragment, 512, NULL, log); printf("Fragment Shader Failed to Compile!\n> OpenGL Error: %s\n\n - - - - - \n\n", log); } unsigned int data = glCreateProgram(); glAttachShader(data, vertex); glAttachShader(data, fragment); glLinkProgram(data); {   char log[512]; int success; glGetProgramiv(data, GL_LINK_STATUS, &success); printf("Program Value: %d\n", data); glGetProgramInfoLog(data, 512, NULL, log); printf("Shader Failed to Link!\n> OpenGL Error: %s", log); } glDeleteShader(vertex); glDeleteShader(fragment); free((void*) vertexcode); free((void*) fragmentcode); Shader* shader = (Shader*) malloc(sizeof(Shader)); shader -> data = data; return shader; } int WinMain(int argc, char const *argv[]) { SDL_Init(SDL_INIT_VIDEO); SDL_Window* window = SDL_CreateWindow("Basic Window", 660, 240, 600, 600, SDL_WINDOW_OPENGL | SDL_WINDOW_SHOWN); SDL_GLContext context = SDL_GL_CreateContext(window);  glewInit();  Shader* shader = createShader("data/test.vs", "data/test.fs"); return 0; } char* loadshader(char* filename) { FILE* file = fopen(filename, "r"); if (!file) return NULL; int flag = 0; char* shader = (char*) malloc(MAXSIZE); char* buffer = (char*) malloc(BUFFSIZE); while (fgets(buffer, BUFFSIZE, file) != NULL) strcat(shader, buffer); free(buffer); fclose(file); printf("\"%s\" Content:\n%s\n", filename, shader); return shader; } 

"data/test.vs" Content: #version 330 core layout (location = 0) in vec3 POSITION; void main() { gl_Position = vec4(POSITION, 1.0); } Vertex File Name: data/test.vs Vertex Code: -1521078208 Vertex Value: 1 Vertex Shader Failed to Compile! > OpenGL Error: ░╗x¥j☻ - - - - - "data/test.fs" Content: #version 330 core out vec4 COLOR; void main() { COLOR = vec4((1.0f, 0.5f, 0.2f, 1.0f); } Fragment File Name: data/test.fs Fragment Code: -1486147520 Fragment Value: 2 Fragment Shader Failed to Compile! > OpenGL Error: ░╗x¥j☻ - - - - - Program Value: 3 Shader Failed to Link! > OpenGL Error: Fragment shader(s) were not successfully compiled before glLinkProgram() was called. Link failed.