I 'm trying to install a graphical interface for a program which i've already got to install succesfully, but the C compiler cannot find some graphical Xwindow libraries.
In the Makefile there is this entry:
gcc -o viewkel $(CFLAGS) $(OBJS) $(LDFLAGS) \
-lm -lX11
Where CFLAGS,OBJS AND LDFLAGS, are already set up in the Makefile. However, when it tries to find X11 it aborts the compilation:
The next paragraph is what i got...is a bit long, but only the last 3 or 4 lines are important, the rest are object files compiled succesfully.
gcc -o viewkel -g -DHIGHPREC -DPARM_FILE=\"/home/che/gsg2/yaehmop/viewkel/new_atomic_parms.dat\" -DX_GRAPHICS -DINTERACTIVE_USE -DINCLUDE_ADF_PLOTS -DCULL_POLYGONS -DSUPPORT_COLOR_X -DINCLUDE_BOND_VALENCE -DSUPPORT_FATBANDS -DCHATTY_SYMMETRY -DSUPPORT_FATBANDS -D_POSIX_SOURCE -DUSE_READLINE -I/mfs/4/usr/X11R6/include main.o interface.o globals.o xstuff.o genutil.o stack.o manipulate.o hierarchy.o snapshot.o fileio.o buttons.o molecule.o solid_stuff.o graphs.o prop_graphs.o band_graphs.o walsh_graphs.o graphics.o tek_lib.o help.o FMO_diags.o orbitals.o fit_orbs.o matrix_ops.o implicit_polyg.o triangles.o 3D_objects.o enhpost.o cont_plots.o contour.o labels.o MO_conts.o vibrations.o valence.o polyhed.o chull.o mem_debug.o -I/usr/include -ireadline -ihistory -L/usr/lib/ -ltermcap -L/usr/lib \
-lm -lX11
/usr/bin/ld: cannot find -lX11
collect2: ld returned 1 exit status
make: *** [viewkel] Error 1
There’s a copy of the X11 library in /usr/X11R6/lib/ directory. I've tried to add
–L/usr/X11R6/lib in many places but it is still not working

Can i get any help please?
