The Linux Programming Interface

41FUNDAMENTALS OF SHARED LIBRARIES

Shared libraries are a technique for placing library functions into a single unit that can be shared by multiple processes at run time. This technique can save both disk space and RAM. This chapter covers the fundamentals of shared libraries. The next chapter covers a number of advanced features of shared libraries.

41.1 Object Libraries

One way of building a program is simply to compile each of its source files to produce corresponding object files, and then link all of these object files together to produce the executable program, like so:

$ cc -g -c prog.c mod1.c mod2.c mod3.c$ cc -g -o prog_nolib prog.o mod1.o mod2.o mod3.o

Linking is actually performed by the separate linker program, ld. When we link a ...