Hello everyone,

when I attempt to run my c++ program, I get a linking error

/usr/bin/ld: -lXft not found

my makefile contains a line X-Lib: ..........,-lXft,..........,-lXmc.

when i search for those lib files, i find that all the files in the above line are present as .a files in /usr/lib whereas the one that it complains Xft has a symbolic link to it in the directory /usr/lib.

Can someone tell me how to get around this problem.

Can someone also tell me what is the difference between .a and .so files.

Hi,

The files with extension .a are static libs, and .so are dynamic libs ...

Are you trying to compile your program or execute it? To compile it you will need to use te devel libs ...

I believe the .a files are archives actually.
ar t <filename>.a
should show you a list of .o files contained in it
.so are shared objects (for dynamic linking) while .o can only (?) be used in static linking

I'm trying to compile my program using my make file.

The only noticeable difference is that all other libraries listed in my make file exist in /usr/X11R6/lib as .a files and the library that creates the problem is present as .so file.

Earlier one of the library path in my makefile for FLTK (a GUI appln that I use along with VTK in my program) contained the following structure

FLTK-LIB: ..................... -libfltk, ......

when I compiled, when linking the program complained that it can't find -libfltk. In the fltk lib directory the name of the library file was libfltk, but for VTK eventhough the library files were named libVTK, in the make file the path was -lVTK. Therefore I decided to change -libfltk to -lfltk and it solved the problem.

I'am confused.

Thanks,
Murali.

you mentioned that libxft was a symbolic link; does the destination of the link exist? if so, look in the make file for a line containing linker options -- often something like LDIR = <some dirs> where the CFLAGS line contains -L$(LDIR) -- and add in the location of the actual object (rather than the link). -L adds extra directories to the path that is search by the linker.
-l<blah> refers to the library blah, whether its a shared object, standard object, or archived object. the filename will have lib prepended to the front. -l is actually an option, and the blah is the argument value