Silviu Sosiade - Linux Programming: Building and Debugging

With the visualinterfaces (KDE , GNOME) that were built specifically for Linux this operatingsystem has become as easy to operate as Windows or MacOS and it is increasinglyperceived less as a operating system for academic or programmers only. Also if you use a setopbox for digital television or if you havean intelligent alarm at home, these devices are likely to use Linux OS as well.That's because Linux operating system has been ported to various types ofprocessors or devices, becoming what we now call "embedded Linux". Although with a very small market share, there are currentlyvariants of mobile phones that use a version of Ubuntu Linux. Whether or notLinux will have a significant market share in the mobile phone market in thefuture, this remains to be seen. But the fact that there are mobile phonesalready using this operating system proves how versatile and flexible solutionLinux has become these days. The first program in Linux was written back in 1991.

This isnearly 25 years ago, which is a considerable age for the software market andand for the IT market in general. In the last 25 years we have seen manysoftware products that had glory days and then replaced by other products. Wehave also seen once renowned companies that are now in the twilight of glory orout of business. Not the same thing happens with Linux. As time passes Linuxbecomes increasingly stronger. The secret of its eternal youth appears to bein using the GNU GPL license, a license that allows anyone to use thisoperating system for free.

Moreover the use of this license has a much widerscope in what free means. This is the freedom to run, copy, distribute,study, change and improve the software. This aspect of freedom is attractinga large number of enthusiasts programmers from all over the world eager tocontribute to the development of Linux. This ultimately creates a synergy hardto replicate for a software system whose code is not visible to the generalpublic and that is developed and maintained only by a company or a group ofcompanies. One thing should be noted here if you do not know this already:Linux is not UNIX. But there is an obvious trend to use these termsinterchangeably.

And that is because there are many common aspects betweenLinux and UNIX, both in terms of usage as well as in term of programming. Notable would also be the fact that there are many similaritiesbetween Android and Linux. Or between Mac OS and Linux. Although there are nocompatibilities at the binary level (the Linux programs can not be executed onMac OS or Android, and vice versa) there are however major similarities interms of operating and programming using these operating systems. And this isunderstandable considering that the development of Android kernel started froman older version of Linux kernel, and various Linux kernel updates happeningnowadays are regularly considered to be imported back into the Android kernel.Also Mac OS started from a variant of UNIX called BSD (Berkeley SoftwareDistribution) that has many similarities with the Linux operating system.Therefore learning Linux opens up larger perspective for the Linux marketitself as well as for other technologies present on the market at the moment. Considering that Linux is gaining more and more ground,programming in Linux is no longer seen as being a niche job anymore.Increasingly more jobs are becoming available and are required for Linuxprogrammers nowadays.

The Linux kernel was initially developed by using the Cprogramming language. Since then, all the development and maintenance has beendone using C. Similarly the majority of libraries and utility programs from adistribution of Linux are also written in C. At the application level, althoughit is possible to use other programming languages (Python , Java , Ruby ...), Cand C++ still remain the preferred languages for many Linux programmers. Theexamples from this book are written in C/C++ therefore a basic understanding ofthe C language would help the reader to better understand the various topicspresented in this book. overview of GNU C/C++compiler. how to build a program frommultiple modules. static and dynamiclibraries in Linux. debugging programs. detecting memory leaks. detecting memory leaks.

The book is particularly useful for those who have programmed inother environments and operating systems before (Windows, for example) and nowwant to understand how to develop programs in Linux. However by explaining the topics from this book in simple termsand by using a lot of examples I am hoping that this book will be a goodstarting point for anyone who wants to learn the basics for how to developprograms in Linux. There are certainly many aspects which are not covered in thisbook. That's because the topics presented in this book are quite extensive andprobably a book alone can be written for each section. But what I am tryingachieve with this book is to provide a sufficient amount of information toallow the reader to understand the fundamental principles of creating programsin Linux and feel comfortable in trying something practical use cases based onknowledge gained from this book.