SIGKILL signal Handler

You cannot, at least not for the process being killed. What you can do is arrange for the parent process to watch for the child process’s death, and act accordingly. Any decent process supervision system, such as daemontools, has such a facility built in.

UDP-Broadcast on all interfaces

First of all, you should consider broadcast obsolete, specially INADDR_BROADCAST ( Your question highlights exactly one of the reasons that broadcast is unsuitable. It should die along with IPv4 (hopefully). Note that IPv6 doesn’t even have a concept of broadcast (multicast is used, instead). INADDR_BROADCAST is limited to the local link. Nowadays, it’s only visible … Read more

Add a bash script to path

Try this: Save the script as apt-proxy (without the .sh extension) in some directory, like ~/bin. Add ~/bin to your PATH, typing export PATH=$PATH:~/bin If you need it permanently, add that last line in your ~/.bashrc. If you’re using zsh, then add it to ~/.zshrc instead. Then you can just run apt-proxy with your arguments … Read more

How is the system call in Linux implemented?

Have a look at this. Starting with version 2.5, linux kernel introduced a new system call entry mechanism on Pentium II+ processors. Due to performance issues on Pentium IV processors with existing software interrupt method, an alternative system call entry mechanism was implemented using SYSENTER/SYSEXIT instructions available on Pentium II+ processors. This article explores this … Read more

Core dump file is not generated

This link contains a good checklist why core dumps are not generated: The core would have been larger than the current limit. You don’t have the necessary permissions to dump core (directory and file). Notice that core dumps are placed in the dumping process’ current directory which could be different from the parent process. Verify … Read more