Git tracks changes as commits. This makes it possible and convenient to check the code change history in a repository. However, this also has side effect. The history consumes storage and the whole repository including the current version of the code files and all the previous changes may be quite large. This is especially a
Read more
Tag: How to
2 Ways of Resetting All Git Submodules in a Git Repository
Posted onGit submodule is a nice and convenient mechanism in Git to include the other Git repositories and manage the version/commit used from the submodule Git repository. However, there are cases where we would like “reset” the submodule, such as when we find updating a submodule repository will break the code tree, or merge some updates
Read more
Install R and RStudio Desktop in macOS
Posted onWe ever discussed How To Install R and RStudio Desktop in Ubuntu Linux 20.04. In this post, we introduce how to install R and RSTudio Desktop on macOS. Install R environment Install R environment as follows using Homebrew. $ brew install R Then verify that the R environment is installed and ready, by running in
Read more
Converting Int to String in C++
Posted onIt is common to convert an integer (int) to a string (std::string) in C++ programs. Because of the long history of C++ which has several versions with extended libraries and supports almost all C standard library functions, there are many ways to convert an int to string in C++. This post introduces how to convert
Read more
How to Migrate RSS Feed Readling List from Feedly to Follow.it
Posted onHaving a reading list from RSS feeds is a convenient way to organize and aggregate various information source from the Web. After Google Reader was retired, many different readers services are available. Feedly and Follow.it are two good choices among those RSS feed readers. Different readers have different features. Follow.it provides features like keyword filtering
Read more
Installing R and RStudio Desktop in Ubuntu Linux
Posted onWe ever discussed How To Install R and RStudio Server in Ubuntu Linux 20.04. If the purpose is to install a local RStudio IDE instead of a remote RStudio Server, we can install RStudio Desktop. In this post, we introduce how to install R and RStudio Desktop on Ubuntu Linux 20.04. For other Ubuntu version,
Read more
Installing R and RStudio Server in Ubuntu Linux
Posted onR is a language and environment for statistical computing and graphics, providing a wide variety of statistical and graphical techniques. The R environment is open source software under GPL. R has rich software packages and is widely used for statistical analysis. RStudio Server is an R integrated development environment (IDE) that provides many useful features
Read more
Git Deleting Remote Tags from the Git Server
Posted onGit’s tags are convenient use to name some specific commits by tagging them for releasing or book keeping purposes. For example, GitHub allows repository managers to make releases using git tags. However, it may happen by mistake that a git tag is pushed to the remote git server while the tag has been made to
Read more
How to Count the Number of Words in a File in PHP?
Posted onCounting the number of words in a file is useful in many programs. In this post, we will discuss how to count the number of words in a file in a PHP script. In PHP standard library, we have function str_word_count($str) which returns the number of words from a string $str. On the other hand,
Read more
How to Make DNF and YUM Save Downloaded RPM Packages
Posted onDNF/YUM can automatically download the RPM packages and install them. Under some situations, we may prefer to make a copy of the RPM files for offline usage so that no need to have network connections to install the software packages. For such purposes, we need to make a copy of the RPM packages. It is
Read more
Compress PNG Images on Linux
Posted onPNG images already use DEFLATE data compression algorithm involving a combination of LZ77 and Huffman coding. But the PNG images can be further compressed by removing non-important metadata or using lossy compression to save storage space and/or data transfer bandwidth. In this post, we introduce 2 compression ways with tools available on Linux. Lossless compression
Read more
Change Another Process’ Environment Variables in Linux
Posted onEach 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
Read more
Redirect Feed Links to follow.it using .htaccess
Posted onFeedburner used to a powerful tool for RSS feeds publishing and subscriber management. However, feedburner will unlikely leave its maintenance mode because there has been no new features yet less features for quite some years. But RSS feed is still an important part of the Web supported by many software such as WordPress. follow.it is
Read more
Make Grub2 Boot Older Kernel Version in Ubuntu 20.04
Posted onIn a Linux system, we may have multiple kernels installed. Usually, it is the latest kernel configured to be the default one the system boot loader will use during automatic boot if there is no manual kernel choosing. In many cases, such as there is no driver ready yet for some devices in newer kernels,
Read more
Add Inline Comments for Multi-line Command in Bash Script
Posted onIn Bash script, it is common that multiple small commands run together connected by pipes (|) and the whole command is quite long. For clarity, we may write the command in multiple lines. How to add comments for these long multi-line commands? In Bash, the content after # in a line is the comment. Using
Read more
How to Match Multiple Lines using Regex in Perl One-liners
Posted onPerl one-liners with perl’s regular expression statement can be a very powerful text processing tools used as commands in a terminal or a script. By default, the input to the perl one-liner with -p or -n options is passed line by line. However, when we want to match multiple lines, it gets us some trouble.
Read more
How to Install Hyperledger Fabric 2.0 in Ubuntu 18.04
Posted onHyperledger Fabric is a consortium blockchain system. It’s performance is relatively good and its modular architecture enables it to be usable in many scenarios. Hyperledger Fabric itself has rich documents and samples of test networks. For beginners, deploying a new network for trying and testing still consumes quite some time. In this post, we will
Read more
Grep 2 Lines using `grep` Command in Linux
Posted ongrep is excellent to match patterns from STDOUT/text files in command line or scripts. It’s handy. Sometimes, our problem is more complex than finding a keyword from a file. On a first thought, it may sound impossible using grep for such complex problems. But grep can be quite powerful than we thought. Today, let’s check
Read more
How to Install Go 1.13.x on Ubuntu 18.04
Posted onIn Ubuntu 18.04 LTS, the default Go lang version is 1.10. For compatibility reason, the Ubuntu LTS will usually keep the major release version numbers for packages. However, many applications, such as Hyperledger Fabric 2.0, require a newer version of Go. In this post, let’s take a look at how to install a system level
Read more
Dynamics 365 Developer Extension is Now Working in Visual Studio 2017
Posted onI don’t know why Jason Lattimer’s D365DeveloperExensions no more working after VS 2017 release? It seems D365DeveloperExtensions anymore supported for newer Visual Studio version. I am pretty much sure, some of you may be still struggling with installing Dynamics 355 Developer extension for your Visual Studio 2017 community or professional edition. Not sure why this tool has been
Read more