A Practical Guide to Red Hat® Linux® 8

Using Shared Libraries

Most modern operating systems use shared libraries, also called dynamic libraries, which are not linked into a program at compile time but rather are loaded when the program starts or later in some cases. The names of files housing shared libraries end with the filename extension .so (shared object). An example is libc.so. Usually libaaa.so is a symbolic link to libaaa.so.x, where x is a small number representing the version of the library. Many of these libraries are kept in /usr/lib: A typical GNU/Linux installation has more than 300 shared libraries in /usr/lib and more than 30 in /usr/X11R6/lib. Applications can have their own shared libraries; for example, the gcc compiler might keep its libraries in /usr/lib/gcc-lib/i386-redhat-linux/3.2. ...