Thread: Xlib not found, Fedora Core 4

The g++ compiler doesn't seem to find Xlib.h on my machine. I know the file is in /usr/X11R6/include/X11. In /usr/include there is a link to the X11 folder. The compiler says this if I run:

Code:

# g++ -o test1.out test1.cpp
/tmp/ccYcKmMS.o(.text+0x11): In function `main':
test1.cpp: undefined reference to `XOpenDisplay'
/tmp/ccYcKmMS.o(.text+0xe0):test1.cpp: undefined reference to `XCreateSimpleWindow'
/tmp/ccYcKmMS.o(.text+0xf1):test1.cpp: undefined reference to `XMapWindow'
/tmp/ccYcKmMS.o(.text+0x108):test1.cpp: undefined reference to `XCreateGC'
/tmp/ccYcKmMS.o(.text+0x11f):test1.cpp: undefined reference to `XSetForeground'
/tmp/ccYcKmMS.o(.text+0x12f):test1.cpp: undefined reference to `XNextEvent'
/tmp/ccYcKmMS.o(.text+0x163):test1.cpp: undefined reference to `XDrawLine'
/tmp/ccYcKmMS.o(.text+0x16c):test1.cpp: undefined reference to `XFlush'
collect2: ld returned 1 exit status

I get the same errors if I run: g++ -I /usr/X11R6/include/ -o test1.out test1.cpp
Here are the contents of test1.cpp:

Code:

#include <X11/Xlib.h>
#include <assert.h>
#include <unistd.h>

#define NIL (0)

int main()
{
Display *dpy = XOpenDisplay(NIL);
assert(dpy);

int blackColor = BlackPixel(dpy, DefaultScreen(dpy));
int whiteColor = WhitePixel(dpy, DefaultScreen(dpy));

Window w = XCreateSimpleWindow(dpy, DefaultRootWindow(dpy), 0, 0, 200,
				100, 0, blackColor, blackColor);

XMapWindow(dpy, w);

GC gc = XCreateGC(dpy, w, 0, NIL);
XSetForeground(dpy, gc, whiteColor);

	while(1)
	{
	XEvent e;
	XNextEvent(dpy, &e);

		if(e.type == MapNotify)
		break;
	}

XDrawLine(dpy, w, gc, 10, 60, 180, 20);

XFlush(dpy);
sleep(10);
return 0;
}

There shouldn't be anything wrong with the source code since I copied it from a tutorial page.

Those are linker errors - you need to link with and specify the path to, the relevant libraries; something like:

Code:

g++ -I /usr/X11R6/include/ -L/usr/X11R6/lib -lX11 -o test1.out test1.cpp

There shouldn't be anything wrong with the source code since I copied it from a tutorial page.

New maxim: third party code rarely builds at the first attempt.

I still get the same errors. Except when i add the -lX11 option I get the error:
/usr/bin/ld: cannot find -lX11

Am I right about that it should work with only the -L/usr/X11R6/lib option?

What do I need to replace the -lX11 option with to avoid the error mentioned above (and possibly get it to work)?

The -L switch provides the linker (ld) with additional library search path(s) - it may be that Fedora has the X-libraries in some other directory(I'm using Slackware); do a

Code:

locate libX11.a

to get that path for your system and use that instead. ie.

Code:

g++ -I /usr/X11R6/include/ -Lyour_path_to_libX11.a -lX11 -o test1.out test1.cpp

The file was in /usr/X11R6/lib64
It works now, thanks for the help!

If anyone else want's to know, the correct command was:

Code:

g++ -L/usr/X11R6/lib64 -lX11 -o test1.out test1.cpp