linux-unix

recent posts related to linux and unix

How to tell grep to ignore special characters in a string (solution)

Back in the old days I thought that any pattern that was including in single-quotes with the Unix grep command meant that the pattern inside the string was completely ignored by grep. But these days I have to escape special characters with a backslash character, which is really annoying. This example shows what I mean:

The Red Hat ethos

The URL contains a statement of the Red Hat ethos. A couple of good quotes:

Open source is a development model, not a business model. Red Hat is in the enterprise software business and is a leading provider to the Global 500. Enterprise customers need products, not projects and it’s incumbent on vendors to know the difference. Open source projects are hotbeds of innovation and thrive on constant change. These projects are where sometimes constant change happens, where the development is done.

How to easily determine the blocksize of a filesystem

I just saw that this is a way you can easily determine the blocksize of a filesystem, at least a Mac/Unix/Linux filesystem:

$ echo foo > foo

$ du -h foo
4.0K    foo

I tried to do the same thing with touch foo, but that didn’t work. Without digging into it more, the key seems to be in having very little text in the file, at which point the du command shows the minimum block size for the file.

Unix find command: How to move a group of files into the current directory

I just bought a bunch of MP3 music files from Amazon, and when I downloaded the zip file they provide onto my Mac, it was a bunch of files in a bunch of subdirectories; not really convenient to work with when you’re trying to import them into iTunes. So I used this Unix find command to move all of the music files from the subdirectories they were scattered in into the root directory that was created when I expanded the zip file:

cd Amazon-Music-Folder
find . -type f -exec mv {} . \;

If you ever need to either copy or move a bunch of files with a single command, I hope this example shows the correct find command syntax for your needs. (If you need to copy the files, use the cp command instead of the mv command.)

How to reset the MySQL root password on an Ubuntu server

As a brief note to self, if you forget the MySQL root password again, these are the steps you followed to create a new MySQL root password on an existing MySQL server running on Ubuntu 16.x:

How to use ‘awk’ to print columns from a text file (in any order)

One of my favorite ways to use the Unix awk command is to print columns of information from text files, including printing columns in a different order than they are in in the text file. Here are some examples of how awk works in this use case.

How to set and use a vim color scheme

In an earlier vim color configuration tutorial I described how to have fine-grained control of your vi and vim color settings. In this article I’ll take an easier route and just show how you can use existing color schemes in your vi editor sessions.

Using a vim color scheme

Using a vim color scheme is actually pretty simple. If you’re in a vim editor session, just issue the vim colorscheme command from last line mode, like this: