Using aliases in Bash

There are certain commands in Linux that I use very frequent (dozens times a day), such as svn, ls, ssh, tar, ps, and a lot more.

All these commands have optional and sometimes required arguments. If you use a command so many times and with a set of recurrent arguments, why don't abbreviate it to save some precious time?

In Bash (and other shells I suppose) you can make aliases or abbreviations to commands using alias.

The syntax is very straightforward:

alias name_of_the_alias="full command to execute when you call to this alias"

Lets say we connect to a subversion service to some server typing every time our user and password.

...
svn --username slizardo --password 'topsecret' up
...
svn --username slizardo --password 'topsecret' up
...
svn --username slizardo --password 'topsecret' up
...

We can simply make an alias on this way:

alias svnx="svn --username slizardo --password 'topsecret'"

From this moment you can call svnx to automatically call the svn command with username and password arguments defined.

svnx up

TIP: How to rotate a page from a PDF

To accomplish this simply task we'll use two tools, gs and convert (imagemagick).

In first place we need to extract the single page from the PDF document and convert it to a PNG image:

gs -q -sDEVICE=png16m -r288 -dBATCH -dNOPAUSE -dFirstPage=1 -dLastPage=1 -sOutputFile=page.png document.pdf

At last, and using the convert utility, we just rotate the previous PNG image the number of degrees we need (90 being a common value).

convert page.png -rotate 90 rotated_page.png

Have fun!

How to be alerted of contents of my interests, when I even don't know them?

That question can be answered with the product AND service we are preparing (already in beta) at nomiss.it (alertas.de for the spanish folks).

If you ask me for a brief definition of the project I will start playing a tape with this recording:

"Notifications service for many types of content (economics, tv, football, jobs), through mobile, email and social networks. Based on user preferences and the information gathered from our sources."

Furthermore, both, users and companies, can benefit from this project. Users from the evident alerts, companies by contracting professional services related with the recommendation system, the message courier (to multiple channels: facebook, twitter, mobile, email, ...) to reach the increasing number of users of our system.

Ok, what are you waiting to try it?

TIP: How to design a business card

With the iWeekend almost here, and taking the networking activities in mind, I will help you to design your own business card.

I'm not a designer, I confess, the real artist on my family is my talented brother Pablo (contact him to design your papers, webs, or movie ads). I will only give you some technical information to create your card in a format ready to be printed.

So, where to start? The first thing to start a standard design are the dimensions. In Spain (where I'm living) the most popular dimensions are 85mm × 55mm.

In relation with the quality for printing, a good value is an image with a resolution of 600 DPI. This will guarantee the images in the card have the same definition as in your monitor.

As an example, I'll leave you here the typical card I use in the events I participate.