This blog is about how to launch a Linux shell command inside a C++ program.
virtualenv creates a virtual python environment inside a project folder of your choice. This enables your to install python packages within the virtual python environment without even having any admin rights on that particular machine. This makes the environment extremely flexible for developers.
A step by step guide for AWS beginners to setup their first AWS account to kick start with AWS cloud technology. It's free!
Operator overloading is one of the fundamental operation which come across often in a C++ program. It is bit cryptic in syntactical side as well as often a misunderstood topic amongst new programmer. I will try to explain this as a series of C++ related notes (as I like to call this) following this post.
Getting Rasberry Pi up and running To bring up your Raspberry Pi (ver 3 B) with NOOBS follow the instructions here. Find the kernel version…
Continue reading → Cross compiling custom Linux Kenel driver for Rasberry Pi Platform
Easy way to install a python module in Anaconda
Handling large file git git. Git LFS is for supporting large files which are bigger than Git's recommended 50MB file size. You cannot push these files to your repository unless you have installed Git-LFS. This post describes the steps involved how to install Git-LFS on a Windows 10 machine.
Once you have created an AWS account it has to be configured. The first thing you need to setup is the second level security called the MFA. This blog takes you through the step by step process of setting up MFA for your root user account.
In one of the previous posts I have described Bringing up Rasberry Pi 3 with NOOBS. But after I brought up the Raspberry Pi (ver…
Continue reading → How to replace the Kernel image in NOOBS with your custom Kernel
Bring up Raspberry Pi To bring up your Raspberry Pi (my Pi is version 3 B) please follow the below link: How to bring up…
Continue reading → Integrating LTE Device EM7565 into Raspberry Pi 3
For formatting the micro SD card I usually use the gparted utility in Ubuntu. Format the micro SD with FAT 32 filesystem format. You need…
Continue reading → Format a micro SD card using gparted utility
How to bring up a Raspberry Pi version 3 B hardware with NOOBS (Raspbian).
I was working with the SieraWireless LTE device drivers recently and I got into a strange issue with one of the drivers called GobiSerial. I…
Continue reading → Unknown symbol usb_serial* in GobiSerial LTE Linux Kernel driver
I was recently working with something which required me to build a code base and flash it into the board (hw) and then once that…
Continue reading → How to pipe one bash command output to another within a python script
If you are working with nuttx kernel you might have issues trying to bring up the kernel menuconfig with the below command: [code language="bash"] make…
Continue reading → nuttx kernel make menuconfig error in Ubuntu
I had written a blog on how to integrate a custom driver into Linux kernel tree previously here. Integrating a custom driver in nuttx kernel is pretty similar. But writing this down would probably be a good idea for any future reference.
Git log [code language="bash"] git log --pretty=format:"%h%x09%an%x09%ad%x09%s" [/code] Adding it to the bash script [code language="bash"] echo "alias gitl='git log --pretty=format:"%h%x09%an%x09%ad%x09%s"'" >> ~/.bashrc source ~/.bashrc…
Continue reading → Useful git command for developers
Stop Ubuntu going into suspended mode Disable suspend $ sudo systemctl mask sleep.target suspend.target hibernate.target hybrid-sleep.target Created symlink /etc/systemd/system/sleep.target → /dev/null. Created symlink /etc/systemd/system/suspend.target →…
Continue reading → General Linux developer’s tips and tricks
Install the arduino IDE 1. https://www.arduino.cc/en/Main/Software/ 2. Select Linux 64 bit 3. Click Just Download Unzip the downloaded file as below: vbhadra@jupiter:~/Downloads$ tar -xf arduino-1.8.10-linux64.tar.xz…
Continue reading → Introduction to Arduino
Time to time we have to work on source code which are downloaded from a git repository, modify the code, implement the functionality, test it,…
Continue reading → How to work in private branch in GIT
Install the custom Toolchain Download and install the toolchain rpm sudo alien ~/Downloads/<toolchain-name>.rpm sudo dpkg -i ./<toolchain-name>.deb Locate the arm compiler sudo find / -iname…
Continue reading → Customizing Qt Creator 5.12.4
How to install pre-build binaries with cmake without forced to be recompile it again.
I do not have administrative rights on a linux server (openSuse Linux) I am working on right now. So installing anything is not an option…
Recently my apt-get install didn't work in Ubuntu 10.04 and I couldn't spend time to fix the source list when it didn't work straight forward.…
Continue reading → How to install vim from tarball?
My favorite git repository is github. It is free unless you want to create a private repository. For private repositories you have to pay a…
Continue reading → How to install and use a GIT client in Windows
Sometimes you may want to take a snapshot of the current state of your virtual machine (in my case Ubuntu Linux) so that you can revert back to it if anything goes wrong in the virtual machine. The feature in VirtualBox which helps in this is called a snapshot. A snapshot is basically a backup of your virtual machine in its current state.
In simple words pthread_join makes the calling thread wait till the newly created thread returns.
Thread-safety of a function refers to the fact whether a function can be safely called from multiple threads simultaneously. Safety here means that even if multiple threads are executing the function simultaneously the data integrity is intact and is not intermingled.
Memory leak is a phenomenon where a running C/C++ program or a running process or thread dynamically allocates memory block from the heap but fails to free the memory block when it no more requires the memory. This happens due to programmatic error where the handle to the allocated memory block gets lost. Over a time if the same programmatic entity (a process, or a thread or a function) comes into action repeatedly and leaks memory, all the free memory of the systems goes away and eventually the systems throws the dreaded "Out Of Memory" and crumbles down.
valgrind is a popular tool which can detect memory in run-time. This blog post discusses how to install, and run valgrind at linux command line to detect memory leak in a sample C program.
This blog post discusses the polymorphism with the help of C++ language. The mechanism to implement polymorphism in C++ is known as Virtual Functions. With the help of a simple example I will try to explain the concept as clearly as I can.
Why virtual functions are required in C++.
Problem Description Suppose you have a local GIT repository where dev-stable-topic is the development branch and time to time the releases are made to…
Continue reading → Git Rebasing
Merge Conflict Often you will encounter merge conflicts while doing rebase operation as described above. Here, is a example merge conflict error: [code language="bash"] $…
Continue reading → How to resolve merge conflict in GIT
In your role as a Marketing Consultant, you have been asked by Wiggo*: a fictitious European supermarket (food retailer) chain (similar to Aldi and Lidl) to research and report on the feasibility of them launching in a new international market (this can be a country or economic zone of your choice and/or one you are familiar with).
As part of iot application development for IoT I had to play around with the SSL connection establishment with the remote mqtt servers. The below…
Continue reading → How to publish a topic with mqtt broker running on iot.eclipse.org server
I was facing an issue recently and it is like this. I run a Ubuntu Linux Virtual Machine on a Windows guest. Because of my…
I was trying to connect to a newly installed Ubuntu Linux version 12.04 using FileZilla but the application kept on timing out. This can happen…
Continue reading → Why cannot connect to linux machine using FileZilla (sftp mode)?
Check if sshd service is running in Ubuntu with the below command: [code language="bash"] vbhadra@vbhadra-VirtualBox:~$ ps aux | grep ssh vbhadra 1702 0.0 0.0 4088…
Continue reading → How to install ssh service in Ubuntu Linux (12.04)
I was facing the issue while trying to connect to a newly installed Ubuntu 12.04 running on a Virtual box. I use FileZilla a lot…
Continue reading → Why cannot connect to Ubutnu linux machine using Filezilla (ftp)?
This may be very simple but to keep things handy the below will install ftp service in you Ubutu Linux machine: [code language="bash"] vbhadra@vbhadra-VirtualBox:~$ sudo…
Continue reading → Installing ftp service in Ubuntu 12.04
Using apt-get install Use the below command on your ubuntu terminal: [code language="css"] $ sudo apt-get install git [/code] Installation from source code But at…
Continue reading → Installing GIT on Ubuntu 12.04
Auto variable An auto variable is a variable which is declared within the scope of a function. We call it local variable as well.…
Continue reading → Auto, static and global variable in C/C++ programming
Source: Let me judge!
Integrating a custom device driver into a Linux reference tree.
In the earlier post I have explained how to add a kernel module as a new buildroot package. You can check that post here: In…
Continue reading → How to create a new package under buildroot
Lets say I have a kernel device driver xyz which is coming as an external module and needed to be integrated with the existing software…
Continue reading → How to add/compile a kernel module as a new buildroot package
[/contact-form] You can modify the kernel command line from the below dts file: ~/repos/solaris_src/linux/arch/mips/boot/dts/xyx/xyz.dts chosen { - bootargs = "console=ttyS0,115200n8 loglevel=8 earlycon=uart8250,mmio32,0x1CC40000,115200 rootwait ro"; +…
Continue reading → How to modify kernel command line
[code language="cpp"] #include <iostream> #include <sstream> #include <stdio.h> #include <string> using namespace std; template <typename T> class Stack { private: int top; T datastore[100]; public:…
Continue reading → Write a program to convert a decimal number to its binary equivalent using stack.
