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Futura97 · 09-12-2002, 20:03

I'm just new to C and im having an error pop up and waas wondering if you guys could help.

This is the program I have

Quote:

#include
#include
#include
#include

int main(void)
{
int gdriver = DETECT, gmode, errorcode;
initgraph(&gdriver, &gmode, "");
errorcode = graphresult();
if (errorcode != grOk) /* an error occurred */
{
printf("Graphics error: %s\n", grapherrormsg(errorcode));
printf("Press any key to halt:");
getch();
exit(1); /* return with error code */
}
line(0, 0, getmaxx(), getmaxy());
getch();
closegraph();
return 0;
}

And these are the Error messages...

Quote:

Linking ..\OUTPUT\NONAME00.EXE:
Linker Error: Undefined symbol _closegraph in module NONAME00.CPP
Linker Error: Undefined symbol _line in module NONAME00.CPP
Linker Error: Undefined symbol _getmaxx in module NONAME00.CPP
Linker Error: Undefined symbol _getmaxy in module NONAME00.CPP
Linker Error: Undefined symbol _grapherrormsg in module NONAME00.CPP
Linker Error: Undefined symbol _graphresult in module NONAME00.CPP
�Linker Error: Undefined symbol _initgraph in module NONAME00.CPP

The program is copied exactly out of the help file in C... its the initgraph function that i got it from.

I'm using turbo c++

Cheers

3Toed · 09-12-2002, 22:16

Firstly, you're missing some filenames after the #include statements. But I'm guessing they removed from the post because they were enclosed in greater than and less than characters.

Since it's a linker error, you need to link the compiled C code with the appropriate link library. Look through the doco that came with that example and see what linker libraries it needs. It'll be some kind of math and/or graphing library. I've never used Turbo C so I don't know that the library names are or what the options are.

EDIT: Another thing I thought of is that examples sometimes are not newbie-friendly. It could be that the functions called by your program (that failed the linker) are supposed to be defined by you in one of the include files or in the main program file itself.

au2_xpack · 09-13-2002, 02:20

I just had a quick look at that example. There's a couple of things you'll probably have to do:

1) One of the include statements refers to "graphics.h", which has an associated graphics library (as 3Toed was saying). So when you compile you need to link it to that library. To do that (assuming you're using the gui not the command line): From the menu click -> [Options] -> [Linker] -> [Libraries] -> and tick the "Graphics Library" box. (make sure the "standard runtime library" is ticked as well (but it usually is)).

2)Try and compile / run the program now. It should at least compile / link and generate a ".exe" file. When you run it, you'll probably get an error, that "egavga.bgi couldn't be found". So to fix that, there's a directory called "bgi" under the directory where your turbo c++ is installed. Copy the egavga.bgi file to the directory which has the executable file you have created. Now hopefully it should work.

Well that's all I did and it worked for me. Good luck :)

laminge · 09-13-2002, 05:09

Too many putah hippies for my liking!

Futura97 · 09-13-2002, 06:34

cool... thanks au2_xpack. That got it working.

But i got the missing bgi error you predicted. I tried adding the directory that it resides in(c:\tc\bgi) in the include directories, but it still didn't work.

So i just copied the bgi files into the c:\tc\bin directory and presto!!

Thanks man...

diesel1336 · 09-14-2002, 16:29

sorry guys but what does the program do??

just curious...

Futura97 · 09-15-2002, 00:23

draws a diagonal line from top left to bottom right. Just a simple program so I can start to get the hang of using basic graphics in C