As a beginner user of Unix or Linux, people would frequently get confused about the use of different directories of the system. For example, there is a /bin directory under root(/), it is used to store binary files. However, there are /usr/bin and /usr/local/bin under /usr which are used for storing binary files as well. Some systems even have /opt/bin. What are the differences among them?Though there are articles explaining different directories in *nix such as Filesystem Hierarchy Standard, it's not clear why these directories are present and their history. Rob Landley filled part ...

diff is an important tool program in Unix. It is used to compare differences of two files, it is the foundation for code version control. If you type :$ diff <file_before_change> <file_after_change>diff will tell you what's the difference between these two files. The result may not be so easy to understand, so now I will show you how to understand diff.1. 3 formats of diffdiff has 3 formats due to historic reasons.normal diffcontext diffunified diff2. Demo filesFor easy demonstration, we create 2 demo files.The first one is f1, it has 7 lines of a in it.aaaaaaaThe second file is f2...

Below is the collection of Linux command line tips which I’ve found useful for Linux users. To get more information about the command mentioned below just open your terminal and type man <command>.Things a Linux user must learnLearn bash: No need to refer a lengthy bash guide or something else. Just read the complete man page of bash (man bash).Learn vim: You might be using Emacs or Eclipse for your work all the time but nothing can compete vim.Learn ssh: Learn the basics of passwordless authentication.Learn basics of bash job management: Using &, Ctrl-C, fg, bg, Ctrl-Z, jobs,...

Every process is initialized with three open file descriptors, stdin, stdout, and stderr. stdin is an abstraction for accepting input (from the keyboard or from pipes) and stdout is an abstraction for giving output (to a file, to a pipe, to a console).That's a very simplified explanation but true nonetheless. Those three file descriptors are collectively called 'The Standard Streams'.Where does stderr come from?It's fairly straightforward to understand why stdin and stdout exist, however stderr seems like the odd one out. Why do we need another stream for errors?This is a quote from Doug McIll...

A few that come to mind, some less known, some more:xargs or parallel: run things in parallel, with lots of optionssed and awk: more well-known but still super useful for processing text files, and faster than Python or Rubym4: simple macro processorscreen: powerful terminal multiplexing and session persistenceyes: print a string a lotcal: nice calendarenv: run a command (useful in scripts)look: find English words (or lines in a file) beginning with a stringcut and paste and join: data manipulationfmt: format text paragraphspr: format text into pages/columnsfold: wrap lines of textcolumn: form...

Now that you have you system and project environment all setup you probably want to start developing. But you likely don’t want to start writing an entire project fully from scratch, as you dive in you’ll quickly realize theres many tools helping you build projects and sites faster. For example making a request to a website there’s Requests, for handling processing images there’s Python Imaging Library, or for a full framework to help you in building a site there’s Django. With all of these there’s one simple and common way to install ...

At Cloudmetrx, we use a lot of C. So given the recent passing of UNIX legend Dennis Ritchie, the creator of the C language, we think a toast to C is only fitting.Our extensive reliance on C is especially unusual considering the other languages in our stack – Clojure, Node.js, and other hipster platforms. We aren't predisposed to using older, "venerated" technologies simply because they're older and venerated. But when it comes to high-performant computation, there's just nothing like C. Some will claim Java, but those people are incorrect. There's nothing like C.In my opinion, the reaso...

As we noted earlier this week, one of the founding fathers of UNIX and the creator of C, Dennis Ritchie, passed away last weekend. While I feel that many in computer science and related fields knew of Ritchie’s importance to the growth and development of, well, everything to do with computing, I think it’s valuable to look back at his accomplishments and place him high in the CS pantheon already populated by Lovelace, Turing, and (although this crowing will be controversial, at least until history has its say) the recently-departed Steve Jobs.UNIX was one of the first multi-user ...