C code for OpenGL 3.3 and GLSL 3.3

//MAIN SOURCE

#include <SDL.h>
#include <GL/glew.h>
#include <SDL_opengl.h>
#include <stdio.h>
#include <conio.h>


#define SCREEN_HEIGHT 480
#define SCREEN_WIDTH 640


SDL_Renderer *mainrenderer;
SDL_Window *mainwindow;
SDL_Event event;
bool running = true;

const char *GetStringFromFile(const char *stringfilename)
{

	FILE *file;
	errno_t err;
	err = fopen_s(&file, stringfilename, "ab"); // open the file at the end and binary
	if (err != 0 )
	{
		printf("can't be opened");
	}


	long length = ftell(file);// Ask the size of the file
	printf("file length is %ld \n", length);
	fseek(file, 0, SEEK_SET); // return to the beginning of the file
	char *buffer = calloc(length + 1, sizeof(char)); // alloc the buffer with the end 0
	fread(buffer, sizeof(char), length, file); // read the file
	fclose(file);
	printf(buffer);

	//FILE *stringfile = fopen_s(&stringfile, stringfilename, "ab"); // open the file at the end and binary
	//int length = ftell(stringfile); // Ask the size of the file
	//fseek(stringfile, 0, SEEK_SET); // return to the beginning of the file
	//char *buffer = calloc(length + 1, sizeof(char)); // alloc the buffer with the end 0
	//fread(buffer, sizeof(char), length, stringfile); // read the file
	//fclose(stringfile);
	//return buffer;
	//printf(buffer);
	//return buffer;
};
GLuint LoadShaders(const char *fragshaderfn, const char *vertshaderfn, GLuint vertshader, GLuint fragshader)
{
	const char * vertfilesource = GetStringFromFile(vertshaderfn);

	int vertlenofstr = strlen(vertfilesource);
	printf("\n\n\n\n this is the length -> %d", vertlenofstr);

	glShaderSource(vertshader, 1,
		&vertfilesource, &vertlenofstr);

	glCompileShader(vertshader);

	const char *vertshaderinfolog[256] = { 0 };
	int vertlenofils = strlen(vertshaderinfolog);

	glGetShaderInfoLog(vertshader, sizeof(char) * 256, vertlenofils, vertshaderinfolog);

	printf(vertshaderinfolog);

	GLuint vertprogram = glCreateProgram();

	glAttachShader(vertprogram, vertshader);

	glLinkProgram(vertprogram);

	const char *vertproginfolog[256] = { 0 };
	int vertlenoffp = strlen(vertproginfolog);
	glGetProgramInfoLog(vertprogram, sizeof(char) * 256, vertlenoffp, vertproginfolog);

	printf(vertproginfolog);

	glUseProgram(vertprogram);


	const char * fragfilesource = GetStringFromFile(fragshaderfn);

	int fraglenofstr = strlen(fragfilesource);
	printf("\n\n\n\n this is the length -> %d", fraglenofstr);


	glShaderSource(fragshader,1,
		&fragfilesource, &fraglenofstr);

	glCompileShader(fragshader);

	const char *fragshaderinfolog[256] = { 0 };
	int fraglenofils = strlen(fragshaderinfolog);

	glGetShaderInfoLog(fragshader, sizeof(char) * 256, fraglenofils, fragshaderinfolog);

	printf("\n\n\n\n FRAG SHADER INFO LOG", fragshaderinfolog);

	GLuint fragprogram = glCreateProgram();

	glAttachShader(fragprogram, fragshader);

	glLinkProgram(fragprogram);


	const char *fragproginfolog[256] = { 0 };
	int fraglenoffp = strlen(fragproginfolog);
	glGetProgramInfoLog(fragprogram, sizeof(char) * 256, fraglenoffp, fragproginfolog);

	printf("\n\n\n\n FRAG PROG INFO LOG",fragproginfolog);

	glUseProgram(fragprogram);

	return fragshader;
	return vertshader;
};


int main(int argc , char **argv)
{
	SDL_Init(SDL_INIT_EVERYTHING);

	mainwindow = SDL_CreateWindow(
		"C OpenGL Engine",
		300, 300, 640, 480,
		SDL_WINDOW_SHOWN | SDL_WINDOW_OPENGL );

	SDL_GLContext maincontext = SDL_GL_CreateContext(mainwindow);
	SDL_GL_MakeCurrent(mainwindow, maincontext);

	glewExperimental = GL_TRUE;
	GLenum err = glewInit();
	GLuint vertshaderhandle = glCreateShader(GL_VERTEX_SHADER),
		fragshaderhandle = glCreateShader(GL_FRAGMENT_SHADER);
	if (GLEW_OK != err)
	{
		/* Problem: glewInit failed, something is seriously wrong. */
		fprintf(stderr, "Error: %s\n", glewGetErrorString(err));
	}
	printf(stdout, "Status: Using GLEW %s\n", glewGetString(GLEW_VERSION));

	if (SDL_GL_SetSwapInterval(1) < 0)
	{
		printf("Warning: Unable to set VSync! SDL Error: %s\n", SDL_GetError());
	}

	//LoadShaders("cunt.frag", "cunter.vert", vertshaderhandle, fragshaderhandle);
	GetStringFromFile("cunt.frag");

	glClearColor(0.0, 0.0, 0.0, 1.0);

	GLuint projmat = glGetUniformLocation(vertshaderhandle, "projection");
	//printf("\n\n\n\n\n\n\n Projmat : %d",projmat);
	while (running == true)
	{
		while (SDL_PollEvent(&event))
		{
			switch (event.type)
			{
				case SDL_QUIT:
					SDL_GL_DeleteContext(maincontext);
					SDL_Quit();

					return 0;
				break;
			}
		}

		glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );

		SDL_GL_SwapWindow(mainwindow);
	}

	SDL_GL_DeleteContext(maincontext);
	SDL_DestroyWindow(mainwindow);
	SDL_Quit();
	return 0;
}


/*int errorflag = glGetError();
if (errorflag == GL_NO_ERROR)
{
printf("something happend maybe?");
}*/
/*char fragfilecontents[500] = { 0 };
char fragshadercompilelogcontents[500] = { 0 };
char fragshaderlength[500] = { 0 };
char fragshadercompilestatus[500] = { 0 };
while ((fragfilecontents[0] = fgetc(fragfile)) != EOF)
{
printf(fragfilecontents);

}

GLuint fragshader = glCreateShader(GL_FRAGMENT_SHADER);

glShaderSource(fragshader, 0,
(const GLchar **)&fragfilecontents, NULL);*/

//glCompileShader(fragshader);
//GLint compile_status;
//glGetShaderiv(fragshader, GL_COMPILE_STATUS, &fragshadercompilestatus);
//printf("%s",fragshadercompilestatus);
//	glGetShaderiv(fragshader, GL_INFO_LOG_LENGTH, &fragshaderlength);
//glGetShaderInfoLog(fragshader, 256, &fragshaderlength, fragshadercompilelogcontents[0]);
//printf("%s",fragshaderlength[0]);

//PROPER READ AND WRITE :
//const char *getStringFromFile(char const *path) {
//	FILE *file = fopen(path, "ab"); // open the file at the end and binary
//	int length = ftell(file); // Ask the size of the file
//	fseek(file, 0, SEEK_SET); // return to the beginning of the file
//	char *buffer = calloc(length + 1, sizeof(char)); // alloc the buffer with the end 0
//	fread(buffer, sizeof(char), length, file); // read the file
//	fclose(file);
//	return buffer;
//}


//CUNT.FRAG
#version 330

out vec4 color;

void main()
{
    color = vec4(1.0, 0.0, 0.0, 1.0);
}