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I am running an OpenGL C++ file with fragment and vertex files. I am on Ubuntu 18.04. The problem is that when I link with g++ command I get errors : my first linking command was :

g++   -o   proj prog.cpp  -lGL -lm

and I am getting these errors :

/tmp/ccdaDttM.o: In function `main':
prog.cpp:(.text+0x18): undefined reference to `glfwInit'
prog.cpp:(.text+0x27): undefined reference to `glfwWindowHint'
prog.cpp:(.text+0x36): undefined reference to `glfwWindowHint'
prog.cpp:(.text+0x45): undefined reference to `glfwWindowHint'
prog.cpp:(.text+0x54): undefined reference to `glfwWindowHint'
prog.cpp:(.text+0x63): undefined reference to `glfwWindowHint'
prog.cpp:(.text+0x84): undefined reference to `glfwCreateWindow'
prog.cpp:(.text+0x9f): undefined reference to `glfwGetFramebufferSize'
prog.cpp:(.text+0xd3): undefined reference to `glfwTerminate'
prog.cpp:(.text+0xe9): undefined reference to `glfwMakeContextCurrent'
prog.cpp:(.text+0xef): undefined reference to `glewExperimental'
prog.cpp:(.text+0xf5): undefined reference to `glewInit'
prog.cpp:(.text+0x22c): undefined reference to `__glewGenVertexArrays'
prog.cpp:(.text+0x241): undefined reference to `__glewGenBuffers'
prog.cpp:(.text+0x256): undefined reference to `__glewBindVertexArray'
prog.cpp:(.text+0x264): undefined reference to `__glewBindBuffer'
prog.cpp:(.text+0x277): undefined reference to `__glewBufferData'
prog.cpp:(.text+0x293): undefined reference to `__glewVertexAttribPointer'
prog.cpp:(.text+0x2bc): undefined reference to `__glewEnableVertexAttribArray'
prog.cpp:(.text+0x2ca): undefined reference to `__glewVertexAttribPointer'
prog.cpp:(.text+0x2f3): undefined reference to `__glewEnableVertexAttribArray'
prog.cpp:(.text+0x301): undefined reference to `__glewBindVertexArray'
prog.cpp:(.text+0x314): undefined reference to `glfwWindowShouldClose'
prog.cpp:(.text+0x326): undefined reference to `glfwPollEvents'
prog.cpp:(.text+0x368): undefined reference to `__glewBindVertexArray'
prog.cpp:(.text+0x38a): undefined reference to `__glewBindVertexArray'
prog.cpp:(.text+0x39d): undefined reference to `glfwSwapBuffers'
prog.cpp:(.text+0x3a9): undefined reference to `__glewDeleteVertexArrays'
prog.cpp:(.text+0x3be): undefined reference to `__glewDeleteBuffers'
prog.cpp:(.text+0x3d1): undefined reference to `glfwTerminate'
/tmp/ccdaDttM.o: In function `Shader::Shader(char const*, char const*)':
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x27b): undefined reference to `__glewCreateShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x28f): undefined reference to `__glewShaderSource'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x2af): undefined reference to `__glewCompileShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x2c0): undefined reference to `__glewGetShaderiv'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x2e7): undefined reference to `__glewGetShaderInfoLog'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x347): undefined reference to `__glewCreateShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x35b): undefined reference to `__glewShaderSource'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x37b): undefined reference to `__glewCompileShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x38c): undefined reference to `__glewGetShaderiv'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x3b3): undefined reference to `__glewGetShaderInfoLog'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x413): undefined reference to `__glewCreateProgram'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x427): undefined reference to `__glewAttachShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x443): undefined reference to `__glewAttachShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x45f): undefined reference to `__glewLinkProgram'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x473): undefined reference to `__glewGetProgramiv'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x49d): undefined reference to `__glewGetProgramInfoLog'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x500): undefined reference to `__glewDeleteShader'
prog.cpp:(.text._ZN6ShaderC2EPKcS1_[_ZN6ShaderC5EPKcS1_]+0x511): undefined reference to `__glewDeleteShader'
/tmp/ccdaDttM.o: In function `Shader::Use()':
prog.cpp:(.text._ZN6Shader3UseEv[_ZN6Shader3UseEv]+0xf): undefined reference to `__glewUseProgram'
collect2: error: ld returned 1 exit status

When I googled, I found this post : undefined reference to `__glewCreateShader` and according to the post, I changed the command to :

g++   -o   proj prog.cpp   -lGLEW  -lm

The long list of errors is reduced but still :

/usr/bin/ld: /tmp/ccSaE0MX.o: undefined reference to symbol 'glDrawArrays'
//usr/lib/x86_64-linux-gnu/libGL.so.1: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

I viewed several posts and they almost say the same thing OpenGL library not linking

The command I tried :

g++   -o   proj prog.cpp   -lGLEW  -lm -lGLU -lglut
g++   -o   proj prog.cpp   -lGL -lGLEW  -lm
g++   -o   proj prog.cpp   -lGLEW  -lGL -lm
g++   -o   proj prog.cpp   -lGLEW -lopengl32 -lm
g++ prog.cpp -lGL -lGLU -lGLEW -lGLFW -lm
g++ prog.cpp -lGL -lGLU -lGLEW -lglut -lm -o   proj

include :

#include <iostream>

#define GLEW_STATIC
#include <GL/glew.h>
#include <GLFW/glfw3.h>
#include "Shader.h"

Update : here is what I am getting now

g++   -o   proj sample.cpp  libglut.a -lGL -lm 

/usr/bin/ld: libglut.a(glut_event.o): undefined reference to symbol 'XWithdrawWindow'
//usr/lib/x86_64-linux-gnu/libX11.so.6: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status

Please tell me what am I doing wrong. Thanks

Sea
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  • I had similar kind of linking errors in the past: it was unclear to me which library I needed to link with. So what I did was that I learned how to use various development tools, like `nm` and `objdump`, to search the libraries on my system for the one that I had to link with. From that point on I was able to figure this out in a few seconds, every time, and I didn't need to post a question to Stackoverflow every this happened, and then wait hours or days hoping for an answer. – Sam Varshavchik Jan 10 '21 at 23:12
  • @httpdigest I used GLFW and it gives me an error /usr/bin/ld: cannot find -lGLFW – Sea Jan 11 '21 at 00:45
  • Are you including the headers GLEW provides? You may need to use those instead of linking against OpenGL directly. (This is a guess, it's been a long time since I used GLEW.) – Andrea Jan 11 '21 at 11:17
  • @httpdigest yeah it is there in /usr/lib/x86_64-linux-gnu/ . Still does not work – Sea Jan 11 '21 at 15:33
  • @Andrea posted the include code above. I really dont know hat I am doing wrong – Sea Jan 11 '21 at 15:34

0 Answers0