On 02.09.2012 09:53, Rahul Bansal wrote: since you are including this path assume you use -I/path/to/libvirt/source and don't have libvirt installed in your system. Hence you need to provide linker the path where it will find the library: gcc -I/path/to/libvirt -L/path/to/libvirt/src -lvirt ex1.c -o ex1 or just install libvirt ('sudo make install' in /path/to/libvirt) and then you can drop both -I and -L arguments.