An IPv6 is a preferred protocol over IPv4 in modern Windows and Linux systems. In Linux, you can ping IPv6 addresses using a standard ping command as well as a special ping6 command. This short note shows how to ping the IPv6 addresses in Linux.
linux
OOM Killer Doesn’t Work Properly [SOLVED]
An out-of-memory (OOM) killer is a mechanism of the Linux kernel that is supposed to terminate (kill) high memory consuming processes if a system is critically low on memory. Unfortunately, the OOM killer doesn’t always work properly. It often starts too late, when the system is already out of memory, so it doesn’t have enough […]
Restart X Server – Ubuntu Linux
While working on a Linux systems like Ubuntu, Linux Mint, etc., through a graphical user interface (GUI) it may happen that some application will hang the GUI and freeze a system. To unfreeze the system without rebooting a machine we can restart an X server (also known as X11, or just X) that is the […]
Systemd Service Not Starting (status=217/USER)
A systemd service may fail to start with the error: Main process exited, code=exited, status=217/USER The status=217/USER indicates that the user that is configured to run the service could not be found. This could happen if there is a typo in a username or you have copied a service file from another machine and it […]
Linux Mint: Lock Screen on Lid Close – Enable/Disable
When a laptop lid is getting closed, different scenarios are possible: do nothing, blank screen, suspend or shutdown. In Linux Mint, the system behavior on closing the lid is controlled by the “Power Management” and “Screensaver” settings. This note shows how to enable or disable screen locking when closing the lid in Linux Mint.
Linux: Find Files by Name & Grep Contents
The Linux find command can be used for searching files and directories and performing subsequent operations on them. If you use the find command to recursively search for some files and then pipe the result to the grep command, by doing this you will actually parse the file paths/names but not their contents. This short […]
“Show Desktop” Shortcut in Linux Mint (MATE)
In Windows, there is a keyboard shortcut ⊞ Win + D used to minimize all the currently open windows and show the desktop. To hide all windows and show the desktop in MATE edition of the Linux Mint there is a Ctrl + Alt + D shortcut.
QR Code Generator – Windows, Linux, MacOS
A QR code generator is an application which creates and stores different types of data in a QR code image file. A qrencode is a free command line tool for encoding string data in the QR code and saving it as a PNG or an EPS image. In this note i will show how to […]
Redirect `STDERR` to `STDOUT` 2>&1
Any command executed in Bash or any other Linux shell, has one input stream (stdin) and two kinds of output streams: standard output (stdout) and standard error (stderr). Each of these streams is represented by a numeric file descriptor: 0 – stdin, the standard input stream 1 – stdout, the standard output stream 2 – […]
Wget: Keep Original Filename
If you try to download a file over HTTP/HTTPS provided by a dynamic link or through a chain of 301, 302 redirects, wget would normally save the file using a part of the URL that you’re using. At the same time, if you use this URL to download the file in a browser, it will […]