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[ More Info ]
I downloaded a YouTube video on a Ubuntu Linux with yt-dlp. When I tried to view the downloaded WebM file with the default video application, Videos, also known as Totem, which is an application for playing videos that is provided with Ubuntu, I saw the message below:
An error occurred
Could not initialise OpenGL support
OK
When I opened the video with
VLC, which I had
previously installed, I heard audio, but no video was displayed. I checked
to see if the Nvidia
driver was up-to-date since the system had an Nvidia graphics card, but they
were up-to-date. You can check that by clicking on the Show Apps
button at the lower-right-hand corner of the screen Ubuntu desktop. Then type
Software Updates in the "Type to search" field. Click on
Software & Updates and then click on the Additional
Drivers.
To resolve the problem, I added the following line to the
/etc/environment file with a
text editor:
GDK_GL=gles
When I rebooted the system, I was then able to view the video with the default Videos application, though when I tried playing it in VLC I could hear audio, but did not see video.
Then from the Behavior tab, I changed the setting from Follow System to Always, which resulted in the scrollbar appearing where it had been missing, but I could not scroll back any further than the text that had been appearing in the tab before I changed the settiing and that remained the same whenever I issued another command and text moved upwards, so that I could no longer see it or scroll back to see it, so I closed the tab.
When I opened another tab, the scrollbar was there and operated as expected.
You can run the Big Fish Games Game Manager on an Ubuntu Linux system under Steam. You can install Steam as a Snap package from the Ubuntu App Center.
Steps:
When I started the install process, the installation appeared to hang at "Execute: C:\Program Files (x86)\bfglient\epoch.exe". When I clicked on the title bar for the window, I saw "About Wine", so it appeared to be using Wine, which I had previously installed on the Ubuntu system. But I waited and eventually the installation succeeded, though I think it took over 15 minutes. I closed the window and then went back to the Steam window, I saw bfginstaller32_s1_l1.exe was still there. This time when I clicked on it, the Big Fish window where I could sign in to Big Fish Games opened fairly quickly.
Note: if the window goes blank or displays just a white background, minimize it by clicking on the "-" in the upper, right-hand corner of the Big Fish window and then switch to it again, which you can do with Alt+Tab — continue to press the Tab key while continuing to hold down the Alt key to cycle between open open windows until you get to the Big Fish window.
Initially, you will see "No games to play," but if you have already purchased games that you've played on another system, you can click on Purchase History and install them on the Linux system. When I installed the Big Fish Games Manager under Steam, I had my wife check one of her games, Aquascapes, and that ran fine. I then closed the Big Fish window and the Steam window and reopened it. Note: if you want to change the name that appears for Big Fish Games in the Uncategorized list, you can right-click on the entry, e.g., bfginstaller32_s1_l1.exe, and choose Properties and then change the "Shortcut" value to something you prefer, such as "Big Fish Games". When I reopened Steam and started Big Fish Games, I saw the Aquascapes game under "My Games".
[ More Info ]
To access a directory that is shared from a Microsoft Windows system in a
Windows domain, you
can take the following steps on a
Ubuntu Linux system.
Note: you will need to have a package installed that provides
Server Message
Block (SMB) support. If the libsmclient0 package is installed, you should be
able to use these steps. You can check if it is installed by opening
a Terminal window and
issuing the command dpkg -s libsmbclient0.
If it is not installed, you can install it with sudo apt install
libsmbclient0.
alice@Wonderland:~$ dpkg -s libsmbclient0 Package: libsmbclient0 Status: install ok installed Priority: optional Section: libs Installed-Size: 259 Maintainer: Ubuntu Developers <ubuntu-devel-discuss@lists.ubuntu.com> Architecture: amd64 Multi-Arch: same Source: samba Version: 2:4.22.3+dfsg-4ubuntu2.2 Replaces: libsmbclient Provides: libsmbclient (= 2:4.22.3+dfsg-4ubuntu2.2) Depends: samba-libs (= 2:4.22.3+dfsg-4ubuntu2.2), libbsd0 (>= 0.0), libc6 (>= 2.38), libndr6 (>= 2:4.17.2), libtalloc2 (>= 2.0.4~git20101213), libtevent0t64 (>= 0.15.0) Breaks: libsmbclient (<< 2:4.22.3+dfsg-4ubuntu2.2) Description: shared library for communication with SMB/CIFS servers This package provides a shared library that enables client applications to talk to Microsoft Windows and Samba servers using the SMB/CIFS protocol. Homepage: https://www.samba.org Original-Maintainer: Debian Samba Maintainers <pkg-samba-maint@lists.alioth.debian.org> alice@Wonderland:~$
[ More Info ]
If you need to list all of the accounts on an Ubuntu Linux system, there are many commands that you can use.
cat /etc/passwdgrep -oE '^[^:]+' /etc/passwd - for just the account namescut -d: -f1 /etc/passwd - for just the account namesawk -F: '{print $1}' /etc/passwd - for just the account names
lsloginscompgen -u - for just the accunt namesgetent passwd[ More Info ]
If you need to determine the amount of memory in a system that is running
the Ubuntu Linux
operating
system (OS), you can open a
Terminal
window from the App Center and then use the free command.
If you use the command without any options, you will see the amount
of memory displayed in
bytes. To display the value in a more human-friendly format, you
can add the argument -h or --human, e.g.,
to see the value in
gigabytes.
alice@firefly:~$ free -h total used free shared buff/cache available Mem: 14Gi 2.4Gi 10Gi 426Mi 2.3Gi 12Gi Swap: 4.0Gi 0B 4.0Gi alice@firefly:~$
Other options for the command are shown below:
jim@Serenity:~$ free --help Usage: free [options] Options: -b, --bytes show output in bytes --kilo show output in kilobytes --mega show output in megabytes --giga show output in gigabytes --tera show output in terabytes --peta show output in petabytes -k, --kibi show output in kibibytes -m, --mebi show output in mebibytes -g, --gibi show output in gibibytes --tebi show output in tebibytes --pebi show output in pebibytes -h, --human show human-readable output --si use powers of 1000 not 1024 -l, --lohi show detailed low and high memory statistics -L, --line show output on a single line -t, --total show total for RAM + swap -v, --committed show committed memory and commit limit -s N, --seconds N repeat printing every N seconds -c N, --count N repeat printing N times, then exit -w, --wide wide output --help display this help and exit -V, --version output version information and exit For more details see free(1). jim@Serenity:~$
Note:The free command in Linux shows the total amount of installed physical memory in the total column, but this value is less than the actual hardware random-access memory (RAM) installed because the Linux kernel reserves a portion of memory for itself and for hardware devices (like video card buffers) at boot time. The total shown is the usable RAM available to the OS, not the absolute hardware total.
[ More Info ]
On a Ubuntu Linux system,
you can determine which users are allowed to use the
sudo command by looking
at the contents of the /etc/group file. If you
grep for sudo
you will see which accounts on the system can use the command.
jack@firefly:~$ grep sudo /etc/group sudo:x:27:jack,jill@ad.example.com jack@firefly:~$
The above output shows that the local jack account and a
Windows domain
account, jill@ad.example.com, can use the command.
You can see what groups a particular user belongs to with the command
groups username, where username is the user's
account name.
jack@firefly:~$ groups jill@ad.example.com jill@ad.example.com : domain users@ad.example.com ra_allowmediaaccess@ad.example .com ra_allowcomputeraccess@ad.example.com ra_allowaddinaccess@ad.example.com ra _allowshareaccess@ad.example.com ra_allowremoteaccess@ad.example.com wssusers@ad .example.com ra_allowvpnaccess@ad.example.com ra_allowhomepagelinks@ad.example.c om jack@firefly:~$ groups jack jack : jack adm cdrom sudo dip plugdev users lpadmin jack@firefly:~$
You can also determine if a user has sudo privilege using
groups username | grep -c sudo. If the result is 0, then
the user does not have that privilege. If the result is 1, inciding that
the grep command found username one in the output of the groups command,
then the user has that privilege.
jack@firefly:~$ groups jill@ad.example.com | grep -c sudo 1 jack@firefly:~$
You can grant a user that privilege by issuing the command
sudo usermod -aG sudo username from an account that already
has the capability to run the sudo command.
jack@firefly:~$ sudo usermod -aG sudo mary [sudo: authenticate] Password: jack@firefly:~$
You can remove a user's account from the list of those allowed to run
the command using the
gpasswd
command, which is part of the sysutils package by issuing the command
sudo gpasswd -d username sudo.
jack@firefly:~$ sudo gpasswd -d mary sudo Removing user mary from group sudo jack@firefly:~$ groups mary | grep -c sudo 0 jack@firefly:~$
[ More Info ]
You can check the health of a NVM Express (NVMe) drive on an Ubuntu Linux system using the nvme-cli command-line interface (CLI) application. The description for the package is as follows:
NVMe management command line interface
nvme-cli is a NVMe management command line interface. NVM Express™ (NVMe™) is a specification defining how host software communicates with non-volatile memory across a PCI Express® (PCIe®) bus. It is the industry standard for PCIe solid state drives (SSDs) in all form factors (U.2, M.2, AIC, EDSFF).
You can install nvme-cli throught the App Center on a Ubuntu Linux system.
[ More Info ]
sudo hostnamectl set-hostname newname where
newname is the new name you wish to assign to the system. E.g.:
jim@Firefly:~$ sudo hostnamectl set-hostname Smaug [sudo: authenticate] Password: jim@Firefly:~$
That will change the host name stored in /etc/hostname.
/etc/hosts file, replacing the old host name
there with the new one. E.g., if I had the following lines in the hosts
file, I would modify the second line containing the old host name.
127.0.0.1 localhost 127.0.1.1 Firefly
The 127.0.0.1 in the above lines is the
localhost IP address,
a loopback address that can be used when troubleshooting network issues.
Ubuntu also adds a 127.0.1.1 address in /etc/hosts with
the name you have assigned to the system. The name should match the
one in /etc/hostname, so change the name for the 127.0.1.1
address to the new name you wish to use.
References:
