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Oracle Virtual Machine Creating Shared Folder and its Permission in Ubuntu guest

Explaining the Steps for sharing a folder on Oracle VM with Windows Host and Ubuntu Guest

VirtualBox’s Shared Folders feature works with both Windows and Linux guest operating systems.
Steps to follow to do this is as follows



1) Install VirtualBox’s Guest Additions in the guest virtual machine.
After the guest os(Ubuntu) is booted,
click the “Devices” menu and choose the
“Insert Guest Additions CD image” option.
This inserts a virtual CD that you can use within the guest operating system to install the Guest Additions.

2) we need to reboot the VM Guest

3) Creating a shared folder
from the menu

Devices -> Shared Folder -> Shared Folder Settings

Select a folder to be shared between Windows and Ubuntu
Reboot the VM

4) Now we should be able to see the shared folder in /media/sf_*****

5) Setting Permission

 But now when you click using browser or change directory you will see permission issue. For this we need to run the below command in terminal

sudo adduser <your_user_name> vboxs…

Using adb shell for dialing and receiving calls in andoird

You have to enable the Developer Options and also the USB debugging We can use adb to trigger a call, receive incoming call, see the below adb commands For dialing a call using activity manager adb shell am start -a android.intent.action.CALL -d tel:123456789 accept/receiving an incoming call: adb shell input keyevent 5 hang up/stop phone call: adb shell input keyevent 6

Mysql Uninstall from Ubuntu 16.04

Follow the steps

1) sudo apt-get remove dbconfig-mysql
2) sudo apt-get remove --purge mysql-server mysql-client mysql-common

iperf3 compilation for ARM in Ubuntu

For compiling for ARM target board

Get the cross compiler details and pass it as argument to the configure script. I used iperf-3.1.3
Below method is for building iperf3 as static, so that we need to push only the iperf3 binary , without any shared libraries

First this assumes you had set the ARM compiler in the path

cd iperf-3.1.3/

1) ./configure --host=arm-linux-gnueabi CC=arm-linux-gnueabi-gcc CXX=arm-linux-gnueabi-g++ CFLAGS=-static CXXFLAGS=-static --enable-static --prefix=`pwd`/output

2) make install


the binary will be available inside output/bin/

Increasing the linux terminal console column width and number of rows

very useful tip for embedded Linux engineers and those who work with Linux Console using minicom or teraterm


very useful tip for embedded Linux engineers and those who work with Linux Console using minicom or teraterm
normally if we type ps in serial console, it will show the process , if the length is more than 80 character(which is default) we cannot see the string after 80 characters in the consol,
with the below command you can adjust the width of the terminal with cols argument and number of rows using the  argument rows to the command stty
stty cols 160 rows 40 this can be used separate also stty cols 160 stty rows 50
Hope this help in ps and htop command when u run and other applications


accessing serial port in linux/ubuntu as a normal user

For accessing serial port in linux/ubuntu as a normal user,we need to add the user to the dialout groupfollow the below commands sudo adduser second_user dialoutor sudo adduser `whoami` dialout

Linux File Permission in octal format in terminal or command line

To see the file permission in Linux terminal use the below command

stat -c "%a %n" *

* = will list and show all files , replace with the fie name if you want to know only for one filename