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Welcome to my blog !!!

My website was born on 1997, I closed it many years ago due to the social networks advent.
Actually I notice that Social Networks have some limits, for this reason I opened a new blog about the Information Technology: my world.
I hope to be able to post some useful stuffs
I’m waiting your suggestions & feedbacks, in the meanwhile. please excuse me for my bad english :-)

Peppe La Rosa

Fast audio format convertion using ffmpeg

FFMPEG is the swiss army knife of Internet Streaming. As written in the homepage “is a very fast video and audio converter that can also grab from a live audio/video source. It can also convert between arbitrary sample rates and resize video on the fly with a high quality polyphase filter. “

Now, we are going to convert all FLAC files from a specific directory to MP3 256K.  It’s not a good idea from the quality perspective, but, you know, some players don’t support FLAC file.

First step is installing FFMPEG with all required codecs. If you are using a Debian base distro just run the following command:

# sudo apt-get install ffmpeg lame flac

unfortunately, ffmpeg is not part of Ubuntu 14.04 official repositories, so we need to add it before installing it:

# sudo apt-add-repository ppa:jon-severinsson/ffmpeg
# sudo apt-get update

Now from the source directory we can run something like that:

# (for FILE in *.flac ; do ffmpeg -i "$FILE" -f mp3 -ab 256000 "`basename "$FILE" .flac`.mp3" || break; done

this is only an example: ffmpeg can handle a lot of formats. To have a list:

# ffmpeg -formats

I suggest to read the official doc to go in deep

RoR: How to test a confirm dialog with Capybara?

Capybara is a great Gem about integration tests in Ruby on Rail. It simulates how a real user would interact with your application by the browser.
This post explains how to face the javascript confirmation pop up windows (“Are you sure?”).
Seems like there is no way to handle it in Capybara but, If you’re using a drivers that supports JavaScript as Selenium, the best solution is override the confirm method to always return true.


page.evaluate_script('window.confirm = function() { return true; }')
page.click('Destroy')

Learn VIM

Link

A great resources collection about VIM (expecially for Rails developer) by thoughtbot

“Unfortunately” some resources are not free, but it’s worth going to visit the website in any case.

Learn VIM

dmesg using human readable output format

dmesg – print or control the kernel ring buffer

dmesg output drives me crazy due to the timestamp. A lot of times I said: “there must be a way to human readable date !!!”  and now it is:

# dmesg -T

No vars and conversions, just a simple option !!

Unfortunately this option doesn’t work on old dmesg releases. On Ubuntu 12.10 (utili-linux v2.20), it works, no way for Red Hat 6 .

Fedora 19 (util-linux 2.23) can do better using color output and pager by the following option:

# dmesg -H

If  -T and -H option are not available, you can use the follow script:

# dmesg | awk -F ] '{"cat /proc/uptime | cut -d \" \" -f 1" | getline st;a=substr( $1,2, length($1) - 1);print strftime("%F %H:%M:%S %Z",systime()-st+a)" -> "$0}' | more

 

Vim as a Python IDE

Are you looking for the best Python IDE ?

From my point of view Vim is the best IDE, but you need to configure it properly to have debug, auto-indent &auto-completion features on it.

Martin Brochhaus at PyCon Asia Pacific 2012 Conference talk about use Vim as Python IDE using some cool plugins.

This is the code on Github:

GitHub vim-as-a-python-ide

You can also find the slides as a PDF in this repository and, above all, download the .vimrc file .

Another valuable link about customize Vim and install plugin is: How I boosted my vim

Linux commands in a nutshell

writing down a series of posts about GNU Linux commands.is one of the main purposes of this blog.
In these posts we are going to review some Linux commands with practical examples.This is not a complete but it’s a compact list of commands to refer when needed.These posts are not a linux training or a complete guide: you can use manpages for that (aka RTFM)The goal is share information about GNU Linux commands , improve my knowledge and use this website to cut & paste commands that I’m not able to remember :-)

Bug fixes, suggestions and feedbacks are welcome as usual !

Posts list:

dmesg using human readable output format