Ubuntu 20.04 LTS brightness control with command line[SOLVED]

While I moved my kernel face from 18.04  to 20.04 LTS,there were few irritants while I got adapted to new interface and features…and one of them was the missing brightness tab in Ubuntu 20.04 LTS. Don’t know why it was removed,but then may be a small community used it and so was discontinued. So I tried third party plugins, few new brightness apps also tried brightness controller but somehow was not happy with the desired screen brightness control.Though Ubuntu 20.04 has night light feature wherein you can tweak with color temperatures from  less warm to more warm but that too fall short of my requirement. So I just wanted a clean hassle free solution. So I got to know about the xrandr command. Xrandr is used to set the size, orientation and/or  reflection  of  the outputs for a screen. It can also set the screen size. 

The good thing is that this utility comes pre-installed with the OS. You just need to use it vide few command line inputs and these are as below:

The first command is

xrandr | grep " connected" | cut -f1 -d " "

This command basically gives you an output of the name of your monitor. In my case it gives HDMI-0.

 

After this command you need to use the same command with different switch and adjusting the brightness to suit your eyes. While 1 refers to highest brightness 0.1 refers to the lowest.So in bright rooms if you wish to set like me,I generally prefer 0.7.The command line goes like this:

 xrandr --output HDMI-0 --brightness 0.7

Other functions that this utility can assist you are with setting resolution and refresh rates. The command lines are mentioned below:

 

SETTING RESOLUTION

xrandr --output HDMI-0--mode 1680x1050

SCREEN REFRESH RATE

xrandr --output HDMI-0--mode 1680x1050 --rate 60.00

Another switch –q will query your monitors and give details as seen below

 Just remember to change your screen name as per your monitor name...in my case like I said...it is HDMI-0.

Broadcom Wireless Drivers Installation : Ubuntu[SOLVED]

While one installs a fresh Ubuntu OS in any machine,typically he finds an initial deterrent as the Wifi adapter is not found  installed.This post gives a step by step direction on how and what to do,to get the Wifi working....and this happens since the same is not installed by default.

Since the PCI.ID initials for any Wifi broadcom adapter is prefixed 14e4,thus first we need to find the exact PCI.ID

Type 

lspci -nn -d 14e4:

Once you get the PCI.ID,you just need to ref the following table and find the corresponding driver to be installed.In our case is 14e4:4365 rev 01,so we choos the corresponding bcmwl-kernel-source

PCI.ID              14.04 LTS                        16.04+
------------------------------------------------------------------------------------
14e4:0576           Special Case #1                   UNKNOWN      
14e4:4301           firmware-b43-installer            firmware-b43-installer      
14e4:4306           firmware-b43-installer            firmware-b43-installer      
14e4:4306 rev 02    firmware-b43-installer            firmware-b43-installer      
14e4:4306 rev 03    firmware-b43-installer            firmware-b43-installer      
14e4:4307           firmware-b43-installer            firmware-b43-installer      
14e4:4311           firmware-b43-installer            firmware-b43-installer      
14e4:4311 rev 01    firmware-b43-installer            firmware-b43-installer      
14e4:4312           firmware-b43-installer            firmware-b43-installer      
14e4:4313           firmware-b43-installer            firmware-b43-installer               
14e4:4315           firmware-b43-installer            firmware-b43-installer      
14e4:4315 rev 01    firmware-b43-installer            firmware-b43-installer
14e4:4318           firmware-b43-installer            firmware-b43-installer                
14e4:4318 rev 02    firmware-b43-installer            firmware-b43-installer                
14e4:4319           firmware-b43-installer            firmware-b43-installer               
14e4:4320 rev 02    firmware-b43-installer            firmware-b43-installer               
14e4:4320 rev 03    firmware-b43-installer            firmware-b43-installer            
14e4:4321           firmware-b43-installer            firmware-b43-installer  
14e4:4324           firmware-b43-installer            firmware-b43-installer        
14e4:4325           firmware-b43-installer            firmware-b43-installer      
14e4:4328           firmware-b43-installer            firmware-b43-installer         
14e4:4329           bcmwl-kernel-source               bcmwl-kernel-source        
14e4:432a           bcmwl-kernel-source               bcmwl-kernel-source        
14e4:432b           bcmwl-kernel-source               bcmwl-kernel-source        
14e4:432c           bcmwl-kernel-source               bcmwl-kernel-source        
14e4:432d           bcmwl-kernel-source               bcmwl-kernel-source       
14e4:4331           firmware-b43-installer            firmware-b43-installer          
14e4:4335           firmware-b43-installer            firmware-b43-installer      
14e4:4350           firmware-b43-installer            firmware-b43-installer  
14e4:4353           Special Case #1                   UNKNOWN        
14e4:4353 rev 01    Special Case #1                   UNKNOWN                 
14e4:4357           Special Case #1                   UNKNOWN        
14e4:4358           bcmwl-kernel-source               bcmwl-kernel-source
14e4:4359           bcmwl-kernel-source               bcmwl-kernel-source       
14e4:4360           bcmwl-kernel-source               bcmwl-kernel-source    
14e4:4365           bcmwl-kernel-source               bcmwl-kernel-source      
14e4:4365 rev 01    bcmwl-kernel-source               bcmwl-kernel-source      
14e4:43a0           bcmwl-kernel-source               bcmwl-kernel-source
14e4:43ae rev 02    UNKNOWN                           UNKNOWN     
14e4:43b1           bcmwl-kernel-source               bcmwl-kernel-source        
14e4:43b1 rev 03    bcmwl-kernel-source               bcmwl-kernel-source              
14e4:4727           bcmwl-kernel-source               bcmwl-kernel-source        
14e4:4727 rev 01    bcmwl-kernel-source               bcmwl-kernel-source        
14e4:a962           firmware-b43-installer            firmware-b43-installer

Thats all folks...ready to go

segmentation fault Kali Linux 2.0 [solved]

Kali Linux 2.0,the well known Penetration testing distro contains a plethora for digital forensics tools and is widely used by ethical hacker community across the globe.It comes with over 650 tools pre-installed that help  perform tasks like network analysis, ethical hacking, load & crash testing etc. It is powered by Linux kernel 4.0 and has enhanced support for different graphics cards and desktop environments.However ,a small bug as I noticed running two regular commands as apt-get update and msfupdate. Used to get the segmentation fault error as seen below in the screen shot :

Resolved by running the following commands at terminal to open sources.list  file

root@kali:~# leafpad /etc/apt/sources.list

As the file opens, simply select all the existing content in the file and delete it.Further to it cut and paste the following lines in the file and save :  

# Regular repositories

deb http://http.kali.org/kali sana main non-free contrib

deb http://security.kali.org/kali-security sana/updates main contrib non-free

# Source repositories

deb-src http://http.kali.org/kali sana main non-free contrib

deb-src http://security.kali.org/kali-security sana/updates main contrib non-free

and now it should work just as it worked in my case as seen below :

[SOLVED] : Failed to load unit 'HGCM' (VERR_INVALID_PARAMETER)

In one of the recent updates of Virtual Box I got this error on start of the saved state of virtual machine.The error said :

Failed to load unit 'HGCM' (VERR_INVALID_PARAMETER)

The resolve is simple ,no stunts involved, as follows :

Simply right click on the machine and choose "DISCARD SAVED STATE"

Thats it...restart the machine,it should resolve.

[SOLVED]: /sbin/mount.vboxsf mounting failed with the error protocol error ubuntu

1. It had never happened in recent past and every time I used to mount the share folder for the guest OS in virtual box it used to happen vide this command :

sudo mount.vboxsf sharedfolder /mnt/foldername

where sharedfolder is the new folder you have created inside guest OS home directory in virtual box ~ ie /home to be mounted with another folder from host OS as foldername here

but today it showed an error with the following message :

/sbin/mount.vboxsf mounting failed with the error protocol error

as seen below :

tried everything around with the commands but didn't get resolved before I attempted to do the more simpler thing of going to the pwd of the folder where I created it to be mounted and typed the same command without path

surprisingly it worked!!!!

Unsupported version 11 of data unit 'vga' : SOLVED

In one of my recent updates in UBUNTU 14.04 LTS,I faced an issue in the installed virtual box machines giving a message that goes as follows :

Unsupported version 11 of data unit 'vga' (instance #0, pass 0xffffffff) (VERR_SSM_UNSUPPORTED_DATA_UNIT_VERSION).

Result Code: NS_ERROR_FAILURE (0x80004005)
Component: Console
Interface: IConsole {1968b7d3-e3bf-4ceb-99e0-cb7c913317bb}

This was in-spite of the fact that I had saved my virtual machine in the manner it is supposed be and was not a power off.The machine as made to start vide the VB interface went showing the progress bar but was then followed by this above message.

How I solved this :

After working out many attempts to update and repair the Virtual Box,the simple way worked out like shown in the pic below : 

Yes...it is as simple as choosing the machine and selecting "DISCARD SAVED STATE"

Invalid settings detected Virtualbox Host only Adapter solved

1.   This post will help guys stuck with adding a Host only Adapter in Virtual Box.The screen shots are self explanatory in a step wise manner.First screen shot shows the problem as  seen on the screen....rest on how to resolve.

(Invalid settings detected)

(Go to preferences as shown above)

(No more errors)

 

[SOLVED] : result code ns error failure virtualbox

1. If you ever get this message "result code ns error failure virtualbox" while you use virtual box...don't you worry...simple steps will resolve as follows:.

The screens you see are shown below first just to ensure that your and mine problem is same :

2.    So first thing is your remove Virtual box from the Ubuntu Software Centre or you can remove the same manually from terminally as root with the following commands :

sudo apt-get remove virtualbox-\*

sudo apt-get purge virtualbox-\*

init 6

sudo sh -c "echo 'deb http://download.virtualbox.org/virtualbox/debian '$(lsb_release -cs)' contrib non-free' > /etc/apt/sources.list.d/virtualbox.list" && wget -q http://download.virtualbox.org/virtualbox/debian/oracle_vbox.asc -O- | sudo apt-key add - && sudo apt-get update && sudo apt-get install virtualbox-4.3 dkms

3.     These 4 commands from the terminal should get you through!!! all d best

Kernel panic after Ubuntu 12.04 LTS update : SOLVED

1.   I recently had installed one new VM with Ubuntu LTS 12.04 last week.All was running fine and I ensured it had all the updates but after one last update I could no more boot into the desktop..instead I started getting stuck at the grub and then kind of the following messages :

Kernel panic - not syncing:Attempted to kill init

unable to read itable block

exitcode=0x00000100

2.  After many attempts I could not solve the issue but all went okay after the following were ensured and run...

Step one...start ur PC and choose the previous Linux version for boot.Once you get into the desktop...get to the sudo mode and run the following :

sudo apt-get update

sudo apt-get upgrade

sudo apt-get dist-upgrade

3.  Should solve the panic...after a reboot.....

Fedora 19 USB automount doesn't work : SOLVED

Having installed Fedora 19 Schrodinger's Cat recently, a problem came up that the USB that used to get auto detected in earlier versions stopped working......and could not be seen anywhere in the file manager...and the disk showed the following screen which has no USB disk.

(CLICK ON THE IMAGE TO ENLARGE)

But the good thing is that on doing LSUSB at the terminal it was being shown as follows :

Bus 001 Device 002: ID 4033:0042 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 002: ID 4051:0030 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 3d4b:0008 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1f6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 003: ID 0f6d:081b Logitech, Inc. Webcam C310
Bus 001 Device 004: ID 0c61:4d0f Primax Electronics, Ltd HP Optical Mouse
Bus 002 Device 005: ID 03f0:5201 Sandisk 

so mounted it the terminal way..

make a directory in home by the name of usb

mkdir usb

and

at the terminal type lsblk that will give you where to mount.In my case it is sdc1. My output comes as follows :

NAME            MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
sda               8:0    0 931.5G  0 disk 
├─sda1            8:1    0 488.3G  0 part 
└─sda2            8:2    0 443.2G  0 part 
sdb               8:16   0 465.8G  0 disk 
├─sdb1            8:17   0   100M  0 part 
├─sdb2            8:18   0   500M  0 part /boot
└─sdb3            8:19   0 465.2G  0 part 
  ├─fedora-swap 253:0    0   5.8G  0 lvm  [SWAP]
  ├─fedora-root 253:1    0    50G  0 lvm  /
  └─fedora-home 253:2    0 409.4G  0 lvm  /home
sdc               8:32   1    30G  0 disk 
└─sdc1            8:33   1    30G  0 part /home/kalama/usb
sr0              11:0    1  1024M  0 rom 

now at the terminal simply type

mount -t vfat /dev/sdc1 /home/kalama/usb/


thats it ..now it will start showing when you do df -h as shown below :

[root@localhost ~]# df -h
Filesystem               Size  Used Avail Use% Mounted on
/dev/mapper/fedora-root   50G  4.8G   42G  11% /
devtmpfs                 2.9G     0  2.9G   0% /dev
tmpfs                    2.9G  664K  2.9G   1% /dev/shm
tmpfs                    2.9G  968K  2.9G   1% /run
tmpfs                    2.9G     0  2.9G   0% /sys/fs/cgroup
tmpfs                    2.9G   36K  2.9G   1% /tmp
/dev/sdb2                477M  117M  331M  27% /boot
/dev/mapper/fedora-home  403G  173M  383G   1% /home
/dev/sdc1                 30G   16G   15G  53% /home/kalama/usb

How to find if Python is installed in Linux ?

I was recently playing with Matriux Krypton tool chaosmap....but was unable to use this tool for some error that kept popping up...so I though if at all the PYTHON is installed or not?......the way to check this is to go to the terminal and write :

python -V

and u should see like  : Python 2.6.6

                                         (click on the image to enlarge)