Wednesday, 30 May 2018

Linux from the command line -- Running Linux commands simultaneously with GNU Parallel

Linux from the command line -- Running Linux commands simultaneously with GNU Parallel

I know I've covered parallel before, but you can never have too much information. In this age of multi-core computing, being able to take advantage of those cores is a useful skill.
https://www.techrepublic.com/article/how-to-run-commands-simultaneously-with-gnu-parallel/

Linux from the command line | Linux for sysadmins -- Sending mail from the command line

Linux from the command line | Linux for sysadmins -- Sending mail from the command line

I know we all have gotten used to having access to our e-mail everywhere, on every device, so the thought of sending e-mail from the command line may seem archaic and pointless, but quite the opposite. It's a really handy and powerful tool.
A simple example might be that you're a sysadmin working away on one of a dozen remote servers and you need to finish up editing a config file later. You could, right from the command line of that box, send yourself a quick reminder note and include the config file in question.
Or, more often this is a tool that comes in handy in custom scripts and cron tasks. For example, maybe you have a script that checks the status of a few key metrics on your network every week. It would be nice to be able to e-mail yourself the output rather than having to remotely log in and read log files.
Or, maybe you might have your system e-mail you when any of a list of critical issues occur. Eg, CPU temp crosses a threshold. A certain file-system gets more than nn% full.
https://linuxtechlab.com/mail-command-send-mail-from-terminal/

Linux from the command line -- All about Linux file archiving with tar

Linux from the command line -- All about Linux file archiving with tar

The tar command is the primary archive command in Linux (and UNIX). It's powerful, versatile, and all things considered, not that hard to use.
Think of it as WinZip on steroids.

Originally tar was created to manage backing up everything from single files to entire file-systems onto backup tapes on big UNIX systems. That's how tar got it's name, from Tape ARchiver. These days tar is a jack of all trades when it comes to archiving and compressing files. You can easily backup multiple directories or whole file-systems with all of their file attributes intact. You can choose from multiple compression methods, or no compression which is great for non or poorly compressible files like PDF's.
Basically tar is a core Linux skill.
https://linuxtechlab.com/tar-command-compress-decompress-files/

Saturday, 26 May 2018

Linux tips & tricks -- understanding the mess that is Linux Audio

Linux tips & tricks -- understanding the mess that is Linux Audio

Over the years the Linux audio system has become pretty complex, in part to deal with the realities of a networked operating system. Fortunately most Linux distros have come to grips with this complexity and do a good job of detecting and correctly configuring most audio hardware. However, should a problem arise, having some background on the system can help.

See also: http://www.troubleshooters.com/linux/sound/sound_troubleshooting.htm
https://opensource.com/article/17/1/linux-plays-sound

Wednesday, 23 May 2018

Linux from the command line -- 22 essential security commands for Linux

Linux from the command line -- 22 essential security commands for Linux


https://www.networkworld.com/article/3272286/open-source-tools/22-essential-security-commands-for-linux.html

Linux from the command line -- cat's backwards twin, tac

Linux from the command line -- cat's backwards twin, tac

You should have come across the "cat" command by now. A way to view all of a file or pipe output. "tac" is the same only it displays the file backwards. IE last line first, then the second to last line, and so on.
https://www.howtoforge.com/linux-tac-command/