When working on a large-scale C++ project with multiple dependencies, it can be challenging to understand the relationships between different components and libraries. Thankfully, CMake provides a nifty feature to visualize these dependencies using Graphviz, a widely-used open-source graph visualization software. Using CMake’s –graphviz option and the dot command from Graphviz is a powerful way…
In this post, we will explore a flexible utility function for splitting a string based on a given delimiter using C++ and the standard library. This allows us to break down complex strings into smaller parts that are easier to process and manipulate. The C++ Utility Function to Split a String by Another String Background:…
Cryptocurrency exchanges have revolutionized the way we trade digital assets, with two main types of exchanges dominating the market: decentralized exchanges (DEX) and centralized exchanges (CEX). In this article, we’ll compare the DEX and CEX from a technical perspective. Decentralized Exchanges (DEX) DEX operate on a decentralized blockchain network, such as Ethereum, and are built…
Welcome to the groundbreaking world of cryptocurrency and blockchain technologies! These cutting-edge technologies are shaking up the global financial environment and paving the path for a more transparent and decentralized future. Consider blockchain technology to be a digital counterpart of a ledger book. It is a secure and immutable digital ledger that records all transactions…
Docker is a convenient tool to quick create containers from different Linux images. If we use the common way to start a docker container like docker run image bash, after the the process exists, the container is still stored there. That is, the docker container persists after it has exited. Sometimes, we would like to…
This post summarizes Linux Kernel new features, bugfixes and changes in Linux 4.9.60 Release. Linux 4.9.60 Release contains 24 changes, patches or new features. In total, there are 64,224 lines of Linux source code changed/added in Linux 4.9.60 release compared to Linux 4.9 release. To view the source code of Linux 4.9.60 kernel release online,…
This is the release notes for linux release v2.0 (source code: linux-2.0.tar.gz) with format adjusted by removing/replacing tabs/spaces/new lines/formatting marks. This notes document can give us an understanding of the early development of the Linux kernel. The original ASCII formatted version is at the end of this post. Intro This document contains a list of…
This change “Add support for using a MAX3421E chip as a host driver.” (commit 2d53139) in Linux kernel is authored by David Mosberger <davidm [at] egauge.net> on Mon Apr 28 22:14:07 2014 -0600. Description of “Add support for using a MAX3421E chip as a host driver.” The change “Add support for using a MAX3421E chip…
This post summarizes new features, bugfixes and changes in Linux kernel release 4.19.70. Linux 4.19.70 Release contains 95 changes, patches or new features. In total, there are 101,521 lines of Linux source code changed/added in Linux 4.19.70 release compared to Linux 4.19 release. To view the source code of Linux 4.19.70 kernel release online, please…
Each process has its environment variables in Linux. But is it possible to change another process’ environment variable from another process in Linux? If it is possible to do so, how to do it? There is a trick which can work for some scenarios. First, find out the process ID, then start gdb and attach…
Since version 7, RHEL and CentOS only have 64 bit versions. For some reasons, it’s better to run many Windows applications under 32 bit wine. Like How to Install Wine 32-bit on CentOS 7, this post introduce how to install 32-bit Wine on CentOS 8. Most of the mechanisms are similar yet there are differences….
StoneWall is an interesting problem that requires some brain cycles yet not too complex. It is good software engineer interview question. Here is a C++ solution whose complexity is O(N). #include <stack> int solution(std::vector<int> &H) { int stones = 0; std::stack<int> heights; for (auto h: H) { while (!heights.empty() && h < heights.top()) { heights.pop();…
RSA (Rivest–Shamir–Adleman) is a widely used public-key cryptosystem that is used for secure communication over the internet. In this post, we will explore how to generate a pair of RSA private and public keys in Linux using the OpenSSL library. Generating a pair of RSA private and public keys in Linux using OpenSSL is a…
Google has created an image that tells us its core values are centered around innovation. There are very few companies that can boast a similar level of influence as Google. Nevertheless, we should not only focus on Google’s achievements today but also learn from their journey to the top. We can break down Google’s core…
Big Data has taken a lead in the IT industry and has played a significant role in the Business growth and decision-making processes that gives you an edge over the competitors. This is equally applicable to the organizations as well as professionals existing in the analytics domain. Big Data Analytics bring an ocean of opportunities…
The world of technology has evolved drastically over the last few decades. Almost every aspect of our lives is dominated by technology. At the heart of technology lies computer programming. Computer programming is what dictates the success of the technology. I mean think about it, your smartphone, PC, ETC they all rely on programming. This…
Linux is the most used and well-known open-source operating system for computers, mobile devices, servers, and mainframes, etc. Linux has so many awesome features to serve its users like Live CD/USB. And it is fast, easy and free to use by computers around the world. The kernel is referred to as the essential component of…
How could I log system calls made by another process without using current built in functions like ptrace, strace, audit etc. I think two options are intercepting the system call table, and another is modifying the entry_64.s file. I want to output these system calls to a file. Can’t find any suggestions on this anywhere….
If we want to check one program on one remote server, we need to know this server’s IP and port number. How to get this program’s port number in the remote server? # netstat -tulpn Remember to run this program with root permission since some programs can only be accessed by root.
Within a Bash script, how to judge whether its STDERR is redirected to a file in Bash on Linux? For example, ./script.sh /tmp/log 2>&1 Can script.sh detect that its STDERR is redirected? Knowing the destination file is better. To test whether a script’s STDERR (or STDOUT) is redirected to a file, check by [[ -f…