The use of dynamic link library under Linux

Many of the tools and program modules under Linux are implemented through a dynamic link library.

It is divided into two processes when used:

(1) Need to know the location of the dynamic link library file at compile time

(2) The runtime needs to open the dynamic link library

For the case of (1), specified in the makefile file, the conditions in the (2) need to be specified in the environment variable Ld_library_path; If the program is installed to install make install in, install location if in the system default open dynamic link library path, It is no longer required to be described in the Ld_library_path variable, otherwise it needs to be added to Ld_library_path.