Re: tlug: gcc use

[Takeshi Hakamada <hakamada@example.com>]

From: Muni <fukudam@example.com>
Message-ID: <37FD7F4F.CECECFA2@example.com>
> Hi, I'm a newbie in linux (just installed Vine Linux last week).
> Well, I wanted to learn OpenGL programming, so I downloaded stuffs like
> GL lib and include files from MESA site. The HOWTO says that I'm 
> supposed to copy all the GLlib and includes in /usr/local/lib and
> /usr/local/includes respectively.  Then I tested with demos and they
> didn't run.. So I copied the lib and includes again from the original
> to /usr/lib and /usr/includes. And this time, it worked fine. All the
> demos (except ones which need hardware acceleration) ran.
>    So now I tried to compile one of the sample codes that came with
> the lib. However, it won't compile. gcc returns:
> 
> $ gcc hello.c
> /tmp/cca031351.o: In function `display':
> /tmp/cca031351.o(.text+0x9): undefined reference to `glClear'
> /tmp/cca031351.o(.text+0x20): undefined reference to `glColor3f'
> /tmp/cca031351.o(.text+0x2a): undefined reference to `glBegin'
> /tmp/cca031351.o(.text+0x3e): undefined reference to `glVertex3f'
> /tmp/cca031351.o(.text+0x52): undefined reference to `glVertex3f'
> /tmp/cca031351.o(.text+0x66): undefined reference to `glVertex3f'
> /tmp/cca031351.o(.text+0x7a): undefined reference to `glVertex3f'
> /tmp/cca031351.o(.text+0x82): undefined reference to `glEnd'
> /tmp/cca031351.o(.text+0x87): undefined reference to `glFlush'
> ......
> 
> What am I missing?  Do I need to specify some sort of path to the
> lib or includes?

You need to specify which libraries you link against your program.
Try following compilation:
$ gcc -o hello hello.c -lMesaGLU -lMesaGL -lXext -lXmu -lX11 -lm

'man gcc' tells you about the compile options.

Takeshi

--
Takeshi Hakamada
E-mail: hakamada@example.com, URL: http://reality.sgi.com/hakamada/
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