Linux

I am quite a fan of the D programming language and I think it deserves more attention, even if since a few months it’s becoming more and more popular, as it gained top20 in the TIOBE Index for February 2020. As an experiment in network programming, I took this simple NTP client written in C and translated to D ; in my opinion while it’s keeping the low-level nature, it’s shorter, clearer and more effective. It’s only a dozen lines of code, but full program is available on my github; stars and contributions are welcome! ...

As you may know, you can configure any DHCP server to send many options to the clients; for example to setup dns domains, http proxy (WPAD) and so on. If you need to access these options from a linux client, you must configure the client to ASK the server for the new options, by editing /etc/dhcp/dhclient.conf, and add an entry like: option WPAD code 252 = string; also request WPAD; done that, when you’ll ask for a dhcp, the dhclient process will invoke your hook scripts with two new environment variables, old_WPAD and new_WPAD, with the values before and after the renewal. ...

Recently I have been in a situation where I needed a simple ‘batch’ job scheduler, where I could submit some long-running tasks to a server and have a ‘system’ that serialize access the execution with some basic job control facilities (remove a job from the queue, stop the processing, and so on). Linux printing subsystem is already designed to do this, and we can exploit the CUPS printing subsystem to run our “batch” jobs. ...

Long story short: you have launched your script/program but forgot to redirect the output to a file for later inspection. #!/usr/bin/python3 #sample endless running program that prints to stdout import time,datetime while True: print(datetime.datetime.now().time()) time.sleep(1) Using GNU Debugger you can re-attach to the process, then invoke the creation of a logfile and duplicate the file descriptor to make the system send the data to the new file, instead of the terminal: ...