Help to compile an opengl shader

[Germán Arias]

Hi all

I'm newbie with OpenGL, so I'm trying to make a simple app to draw the famous 
triangle, using shaders and the "modern" opengl (not using glBegin, glEnd, 
glOrtho, ...). But I'm unable to compile a simple shader. The related code is:

- (BOOL) compileShader: (GLuint *)shader 
                 type: (GLenum)type 
                 file: (NSString *)file
{
    GLint status;
    const GLchar *source;
    int InfoLogLength = 0;
    
    source = 
      (GLchar *)[[NSString stringWithContentsOfFile: file
                                           encoding: NSUTF8StringEncoding 
                                              error: NULL] UTF8String];
    if (!source)
    {
        NSLog(@"Failed to load vertex shader");
        return NO;
    }
    
    *shader = glCreateShader(type);
    glShaderSource(*shader, 1, &source, NULL);
    glCompileShader(*shader);
    
    if (status == GL_TRUE)
      return YES;
    else
      return NO;
}

The shader files (I copied these from internet):

#version 330 core

// Ouput data
out vec3 color;

void main()
{

        // Output color = red 
        color = vec3(1,0,0);

}

And:

#version 330 core

// Input vertex data, different for all executions of this shader.
layout(location = 0) in vec3 vertexPosition_modelspace;

void main(){

    gl_Position.xyz = vertexPosition_modelspace;
    gl_Position.w = 1.0;

}

Any advice? Thanks

Germán