Add quick print button for Google Chrome

My friend was recently wondering that why doesn't chrome have quick print button. Back in the days i also got used to that quick print icon in Internet Explorer. And i do remember using it many times.

In chrome, normally you could print by opening Chrome settings tab from right hand side and select "Print...". Alternatively you can print by using keyboard shortcut Ctrl+P (Windows) or ⌘-P (mac).

Since my IE days are long gone, i would still like to have quick print icon in Google chrome. This is how you can get it.

Select "Customize and control Google chrome", from the top right corner next to the address bar.

Note that Show Bookmarks Bar must be enabled. Select Bookmarks -> Bookmark Manager.

While Bookmarks Bar selected, right click anywhere on the window right hand side and select "Add Page".

Left textbox is the name of the bookmark, i made it "Print". Right side is the bookmark URL, we are going to place small javascript to it: javascript:window.print(). Then hit enter and you are done.

Now you should have nice small quick print icon on your bookmarks bar. I wonder if you could actually have cool printer icon on it as well. Need to research that later.

Linux: Bash single line for loop examples

Knowing for loop in bash is definitely one of the most powerful tricks. For instance, it makes processing and reading files quick and painless in most cases. Since there can be countless use cases for this, i will write down some basic use scenarios.

Here is few basic examples that could be useful.

Creating files:

 for i in 1 2 3 4;do touch file"$i";done  
 ls -l  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:31 file1  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:31 file2  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:31 file3  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:31 file4  

Renaming all files within directory:

 ls -l  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic01.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic02.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic03.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic04.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic05.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic06.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic07.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic08.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic09.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic10.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic11.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic12.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic13.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic14.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic15.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic16.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic17.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic18.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic19.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 pic20.JPG  

I want to change rename these pictures as picture_01, picture_02 and so on. I could do this:

 for i in *;do mv $i $(echo $i | sed "s/pic/picture_/");done  
 ls -l  
 total 0  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_01.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_02.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_03.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_04.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_05.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_06.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_07.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_08.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_09.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_10.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_11.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_12.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_13.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_14.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_15.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_16.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_17.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_18.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_19.JPG  
 -rw-r--r-- 1 m 5000 0 Feb 26 21:18 picture_20.JPG  

* wildcard in this bash loop (for i in *) refers to all files within current working directory. That's why this for loop will catch all files.

Jinja2 template engine, simple basics.

Template engines will allow you to keep your HTML code outside of your code base. Managing and generating HTML in code is a bad practise. Templates will also give nice boost for performance and give you more secure system. this naturally depends how you are using your templates.

This is what Jinja2 is hyping in their features list:

Sandboxed execution

Powerful automatic HTML escaping system for XSS prevention

Template inheritance

Compiles down to the optimal python code just in time

Optional ahead of time template compilation

Easy to debug. Line numbers of exceptions directly point to the correct line in the template.

Configurable syntax

I was surprised to see how flexible Jinja2 for instance is. Variables can be modifier by filters you can see the full list of built in filters from here: http://jinja.pocoo.org/docs/templates/#builtin-filters

Here is some basics, which are usually enough to get going.

I'm passing this test data to Jinja2 (I'm using Python):

 template_data = {"page_title": "Testing templating",  
                  "page_text": "This is my Jinja2 rendered web page!",  
                  "loop_data": ["item1", "item2", "item3"]}  

Data is in dict format. It consists title, text and some data for demonstrating looping. Loop data is placed inside a list.

This is my template file:

 <html>  
 <head>  
 <title>{{ page_title }}</title>  
 </head>  
 <body>  
 <h1>{{ page_text }}</h1>  
 Loop data:  
 {% for row in loop_data %}  
  {% if row == "item2" %}  
   <font color="red">{{ row }}</font>  
  {% else %}  
   {{ row }}  
  {% endif %}}  
 {% endfor %}  
 </body>  
 </html>  

Variables are referred with {{ var_name }}.

For loop works like in any other programming language. Just loop list named loop_data and represent its data with variable row in the loop.

There is also a example how simple IF works. Basically when row value hits "item2" in the loop, font color should be in red. You can also specify {% elif %} blocks.