Linux RedHat / CentOS / Fedora : Uninstall a package along with dependencies

If you’ve been wondering how to delete a package you mistakenly installed (or which is no longer needed) along with all its dependencies, here’s a neat way to achieve just that.

The idea is that whenever you use yum to perform some operation on packages, a transaction is created. If you installed a package along with its dependencies, then you can undo just that by undoing that transaction.

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Fedora 20 Linux + bitcoind : Setting up firewalld for running a full bitcoin node

If you feel like running a full bitcoin node on your Fedora Linux server (and it’s a great way to help the bitcoin network if you have spare capacity / bandwidth), you’ll need to update the firewalld rules in order to allow foreign nodes to connect to yours.

Here’s how…
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Docker 101 : Creating an Elasticsearch image

Creating an image in Docker is rather easy and well documented.

You start by editing a file which describes the image, then run a few commands, and voilà.

In this post we’ll cover how to create a very basic Docker image which will let us spawn elasticsearch instances very easily.

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Unix 101 : Showing non-printing characters in text files (ex : DOS files)

A non-printing character is a character which won’t actually get directly printed (or displayed) but rather interpreted. Such non-printing characters are for example line-feed or tabulation. The interpretation of those characters can differ from one system to the next. For example the line-feed character is different on Unix or DOS.

If you need an easy way to confirm that a text file is DOS or UNIX formatted (they differ with respect to the end of line character(s) for example) or if you wish to display normally non-printing characters of a text file, you can use the -vET command line switches of the cat utility.

As explained in the man page :

  • -v : will use the ^ and M- notation for control and multibytes characters
  • -E : will make ends of lines visible
  • -T : will make tabulations visible

For example : Continue reading Unix 101 : Showing non-printing characters in text files (ex : DOS files)