Whenever we specify -lxerces-c, this looks for libxerces-c.so library in the LIBPATH.
Q1. Why are lib files then generated as libxerces-c.so.28?
Q2. How should we link against such libraries?
The only way I can think of is create a soft link libxerces-c.so which links to the file libxerces-c.so.28. I feel this as an overhead to do. Is there any other way around which is better?
The file name has a version number so that you can have one program that uses version 2.8 and a different program that uses version 2.9. This way, adding a new version of the library will not change the behavior of existing programs that use an old library.
Normally, there should also be a file libxerces-c.so which is a sym link to the version of the library you want your newly built programs to use.
Many Unix package managers will have a separate development package that installs the symlink. It sounds like you don't have the devel package installed.
There's one more reason to it: when linking to libxerces-c you also probably include some xerces header files in your program. And those headers are tied latest version of binary library (through libxerces-c.so symlink).
Meaning that if you compile with headers from xerces-2.8 and link libxerces-2.9 library binaries there's a great chance it will not work out.
Think of it as a precaution from mixing headers and binary libraries.