Linux: problem linking with SDL

SDL Development
1

Hi,

I have a weird problem…

I installed SDL 1.1.8 and wrote the following program:

—[CUT]—
// main.cpp
#include <stdio.h>
#include <stdlib.h>
#include “SDL.h”

int main()
{
if ( SDL_Init(SDL_INIT_VIDEO) < 0 )
{
fprintf(stderr, “Unable to init SDL: %s\n”, SDL_GetError());
exit(1);
}
atexit(SDL_Quit);
printf(“blabla\n”);
return 0;
}
—[CUT]—

and the following makefile:

—[CUT]—
all: test

CPPFLAGS = -g -I/usr/include/SDL

LIBFLAGS = -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread

test: main.o
g++ $(CPPFLAGS) $(LIBFLAGS) -o test main.o

%.o: %.cpp
g++ $(CPPFLAGS) -c $*.cpp

clean:
rm -f *.o
—[CUT]—

Typing make produces this:

g++ -g -I/usr/include/SDL -c main.cpp
g++ -g -I/usr/include/SDL -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
-o test main.o
main.o: In function main': /home/jakob/tmp2/main.cpp:9: undefined reference toSDL_Init’
/home/jakob/tmp2/main.cpp:11: undefined reference to SDL_GetError' /home/jakob/tmp2/main.cpp:14: undefined reference toSDL_Quit’
collect2: ld returned 1 exit status
make: *** [test] Error 1

Why is that?? I have tried everything, changing the order of the
$(LIBFLAGS) and adding “-L/usr/X11R6/lib -lX11 -lXext -lXmu -lXt -lXi
-lSM -lICE -ldl -lpthread”…

Please help…–
Jakob Frandsen

2

Try using these lines instead and see what you get.

CPPFLAGS = -g sdl-config --cflags
LIBFLAGS = -L/usr/lib -Wl,-rpath,/usr/lib sdl-config --libs

You can run the sdl-config command by hand on a command line to see what
it is actually adding to your build lines.

JoshOn Tue, Mar 20, 2001 at 07:47:19AM -0800, Jakob Frandsen wrote:

CPPFLAGS = -g -I/usr/include/SDL

LIBFLAGS = -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread

3

Jakob Frandsen wrote:

Hi,

I have a weird problem…

I installed SDL 1.1.8 and wrote the following program:

—[CUT]—
// main.cpp
#include <stdio.h>
#include <stdlib.h>
#include “SDL.h”

int main()
{
if ( SDL_Init(SDL_INIT_VIDEO) < 0 )
{
fprintf(stderr, “Unable to init SDL: %s\n”, SDL_GetError());
exit(1);
}
atexit(SDL_Quit);
printf(“blabla\n”);
return 0;
}
—[CUT]—

and the following makefile:

—[CUT]—
all: test

CPPFLAGS = -g -I/usr/include/SDL
^^^^^^^^^^^^^^^^^
LIBFLAGS = -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
^^^^^^^^^^

Per default, SDL is installed in /usr/local/lib. You can change it to

LIBFLAGS = $(shell sdl-config --libs)

and see if it works.

Regards, Sven

4

Jakob Frandsen wrote:

I have a weird problem…
I installed SDL 1.1.8 and wrote the following program:

Same version I’m using.

I have the following includes – you shouldn’t need SDL_image
unless you’re using the SDL Image library. I’m not sure why
I have the SDL Endian include.

#include <SDL.h>
#include <SDL_endian.h>
#include <SDL_image.h>

—[CUT]—
[… code snips omitted …]
—[CUT]—

The Makefile looks right to me, comparing with what I’m
using.

Typing make produces this:

g++ -g -I/usr/include/SDL -c main.cpp
g++ -g -I/usr/include/SDL -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
-o test main.o
main.o: In function main': /home/jakob/tmp2/main.cpp:9: undefined reference toSDL_Init’
/home/jakob/tmp2/main.cpp:11: undefined reference to SDL_GetError' /home/jakob/tmp2/main.cpp:14: undefined reference toSDL_Quit’
collect2: ld returned 1 exit status
make: *** [test] Error 1

Why is that?? I have tried everything, changing the order of the
$(LIBFLAGS) and adding “-L/usr/X11R6/lib -lX11 -lXext -lXmu -lXt -lXi
-lSM -lICE -ldl -lpthread”…

So far, the only thing I can think of is maybe the libraries aren’t
actually where they belong. Mine are in /usr/lib and include:

libSDL-1.1.so.0
libSDL-1.1.so.0.5.3
libSDL.a
libSDL.la
libSDL.so
libSDLmain.a

(some of which are probably from earlier versions, but you should
have something like this there).

Just in case, here’s the text from my makefile, which does work:#
INCLUDE = -I/usr/include/ -I/usr/include/SDL
LIBS = -L/usr/lib/ -lSDL -lSDL_image -lSGE -lpthread

automanga: automanga2.cpp
g++ $(INCLUDE) $(LIBS) automanga2.cpp -o automanga

blits: blits.c seesdl.c seesdl.h
g++ $(INCLUDE) $(LIBS) blits.c seesdl.c -o blits

–
Terry Hancock
@Terry_Hancock

5

Hi,

I have a weird problem…

I installed SDL 1.1.8 and wrote the following program:

—[CUT]—
// main.cpp
#include <stdio.h>
#include <stdlib.h>
#include “SDL.h”

Where is the SDL.h file located? You may want to try

#include <SDL.h>

or

#include <SDL/SDL.h>

instead of `#include “SDL.h”’ if you do not know specifically where the SDL
header files went.

An error such as this could make the following errors:On Tue, 20 Mar 2001, you wrote:

g++ -g -I/usr/include/SDL -c main.cpp
g++ -g -I/usr/include/SDL -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
-o test main.o
main.o: In function main': /home/jakob/tmp2/main.cpp:9: undefined reference toSDL_Init’
/home/jakob/tmp2/main.cpp:11: undefined reference to SDL_GetError' /home/jakob/tmp2/main.cpp:14: undefined reference toSDL_Quit’
collect2: ld returned 1 exit status
make: *** [test] Error 1

–
Sam “Criswell” Hart <@Sam_Hart> AIM, Yahoo!:
Homepage: < http://www.geekcomix.com/snh/ >
PGP Info: < http://www.geekcomix.com/snh/contact/ >
Advogato: < http://advogato.org/person/criswell/ >

6

The FAQ recommends people include “SDL.h” as opposed to <SDL.h> or
<SDL/SDL.h> since it is supposed to be more portable.–

Olivier A. Dagenais - Software Architect and Developer

“Samuel Hart” wrote in message
news:01032011551202.00770 at CX114229-D…

On Tue, 20 Mar 2001, you wrote:

Hi,

I have a weird problem…

I installed SDL 1.1.8 and wrote the following program:

—[CUT]—
// main.cpp
#include <stdio.h>
#include <stdlib.h>
#include “SDL.h”

Where is the SDL.h file located? You may want to try

#include <SDL.h>

or

#include <SDL/SDL.h>

instead of `#include “SDL.h”’ if you do not know specifically where the
SDL
header files went.

An error such as this could make the following errors:

g++ -g -I/usr/include/SDL -c main.cpp
g++ -g -I/usr/include/SDL -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
-o test main.o
main.o: In function main': /home/jakob/tmp2/main.cpp:9: undefined reference toSDL_Init’
/home/jakob/tmp2/main.cpp:11: undefined reference to SDL_GetError' /home/jakob/tmp2/main.cpp:14: undefined reference toSDL_Quit’
collect2: ld returned 1 exit status
make: *** [test] Error 1

–
Sam “Criswell” Hart AIM, Yahoo!:
Homepage: < http://www.geekcomix.com/snh/ >
PGP Info: < http://www.geekcomix.com/snh/contact/ >
Advogato: < http://advogato.org/person/criswell/ >

7

Hi,

CPPFLAGS = -g sdl-config --cflags
LIBFLAGS = -L/usr/lib -Wl,-rpath,/usr/lib sdl-config --libs

You can run the sdl-config command by hand on a command line to see what
it is actually adding to your build lines.

I already tried this…

$ sdl-config --libs
-L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread

$ sdl-config --cflags
-I/usr/include/SDL -D_REENTRANT

And to no avail… :frowning:

I moved the $(LIBFLAGS) to the end of the linker line though and it gave
a buttload of undefined references from the object files within libSDL…
too many to list here.–
Jakob Frandsen

8

Hi,

I installed SDL 1.1.8 and wrote the following program:
Same version I’m using.

Excellent.

The Makefile looks right to me, comparing with what I’m
using.

So far, the only thing I can think of is maybe the libraries aren’t
actually where they belong. Mine are in /usr/lib and include:

libSDL-1.1.so.0
libSDL-1.1.so.0.5.3
libSDL.a
libSDL.la
libSDL.so
libSDLmain.a

Mine are there too…

Just in case, here’s the text from my makefile, which does work:

INCLUDE = -I/usr/include/ -I/usr/include/SDL
LIBS = -L/usr/lib/ -lSDL -lSDL_image -lSGE -lpthread

Great, thanks… but they reveal no libSDL_image.a file or libSGE.a
file, and from your listing of SDL libraries above, I don’t understand
how it compiles on your machine… :slight_smile:

Would it be too much to ask if you would paste my files into files on
your machine and run make to see if it compiles?–
Jakob Frandsen

9

g++ -g -I/usr/include/SDL -c main.cpp
g++ -g -I/usr/include/SDL -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
-o test main.o

since linking processes the arguments from left to right, you must
put the libraries after your own objects (main.o in this case)

10

Mattias Engdeg?rd wrote:

g++ -g -I/usr/include/SDL -c main.cpp
g++ -g -I/usr/include/SDL -L/usr/lib -Wl,-rpath,/usr/lib -lSDL -lpthread
-o test main.o

since linking processes the arguments from left to right, you must
put the libraries after your own objects (main.o in this case)

Yep, realized that, so I tried it and it gives me a heapload of
unresolved dependencies for X11, Xdga, esd, and lots more… way too
much to list here…–
Jakob Frandsen

11

Please help…

I fixed the problem by installing 1.1.7 instead… serves me right for
installing the latest unstable release I guess… :)–
Jakob F