Dynamic libraries are an important concept in Linux programming that help reduce the size of executable files and improve the overall performance of applications. In this article, we will explore how to create and use dynamic libraries in C programming on Linux.
What are Dynamic Libraries?
Dynamic libraries, also known as shared libraries, are collections of object modules that can be loaded at runtime and executed by an application. They contain functions and other code that can be shared by multiple programs, reducing duplication of code and saving disk space. In Linux, dynamic libraries have a .so file extension and are loaded using the dlopen() function.
Creating Dynamic Libraries
To create a dynamic library in C programming on Linux, we start by compiling our source code into object files using the -fPIC flag to generate position-independent code:
$ gcc -c -fPIC library.c
Next, we link these object files together into a shared library using the -shared flag:
$ gcc -shared -o liblibrary.so library.o
This command will create a shared library named liblibrary.so that can be used by other applications.
Using Dynamic Libraries
Once we have created our dynamic library, we can use it in our C programs by linking it using the -l option followed by the library name. For example, if we have a program called test.c that uses functions from our liblibrary.so library, we can compile and link it as follows:
$ gcc test.c -o test -L. -llibrary
This will compile test.c and link it with our shared library, generating an executable file named test. We can then run the program using the following command:
$ ./test
Conclusion
In this article, we have learned how to create and use dynamic libraries in C programming on Linux. Dynamic libraries are an essential concept in modern programming, allowing us to reduce code duplication, save disk space, and improve performance. By following the steps outlined in this article, you can start using dynamic libraries in your own Linux applications.