Internet is full of information on Linux signals and usage thereof, starting with simple "signal(SIGSEGV, foo)" examples through more complicated tutorials. The purpose of this article is to show the way your applications interface with Linux kernel when it comes to signal handling.

At good old times, memory was an expensive resource and developers had to take care of the size of the programs they create. Imagine how hard they had to work before there were high level languages (like C), before compilers became smart enough to handle all size optimization issues. Speed was also among the concerns, as the hardware was not as fast as it is now. Another headache was the need to interact with the underlying operating system. Or, to be more precise, the need to implement the interfaces (at pre-libc times). Modern operating systems provide a built-in mechanism for that. This mechanism is called API - Application Programming Interface. This mechanism is a blessing and curse in one. On one hand it greatly simplifies the interaction with the OS, on the other hand it just makes your software more vulnerable to hackers and/or malware. In some cases the usage of APIs just gets exaggerated.

We are all familiar with the 'try - except' constructs from C++ (or Java, etc.) code and we all know what this construct is used for. However, I will try to take us deeper into the underlying exception handling mechanism in this post.