How to read .chm files in Ubuntu

This tutorial assumes that you are a sudoer running Gnome

What is .chm

Wikipedia says:

Microsoft Compiled HTML Help is a proprietary format for online help files, developed by Microsoft and first released in 1997 as a successor to the Microsoft WinHelp format. It was first introduced with the release of Windows 98, and is still supported and distributed through Windows XP and Vista platforms.

Install Xchm

The default installation of Ubuntu doesn’t include any reader for CHM help files, but you can add one easily. Continue reading “How to read .chm files in Ubuntu”

Generate a negative random number using JavaScript

Maths

Ok, so you already know how to generate positive rondom numbers but let’s do it again:

To generate a random number varying from 0 to 9 we will use this code:

var randomN = Math.floor(Math.random()*10)

This expression on the right of the “=”

  1. produces a random number from 0 to 1 (excluding 1, say 0.917) with Math.random()
  2. multiplies it by 10 (9.71)
  3. removes decimals (9) with Math.floor

For negative values from -9 to 0 we will  simply subtract 9 from the previous result:

var negativeRandomN = Math.floor(Math.random()*10) - 9

Now what if you wanted a rondom integer from -10 to 20… ?
Yes you guessed it right! we will generate a random number from 0 to 30 then substact 10 from it

var randomN = Math.floor(Math.random()*31) - 10

So the rule is:
To generate a random integer from m to n, here is the code

var randomN = Math.floor(Math.random() * (n-m+1)) + m

Examples

# Random integer from 1 to 10
var randomN = Math.floor(Math.random() * 10) + 1

# Random integer from -100 to 100
var randomN = Math.floor(Math.random() * 201) -100

# Random integer from 0 to 255
var randomN = Math.floor(Math.random() * 256)

On my WordPress theme, How can I find which page is being requested by the visitor?

So you want to know if the visitor is viewing the homepage, a category or a page? WordPress have easy functions for that:

  • is_home() : returns true if the visitor is viewing your blog homepage
  • is_category() : returns true if viewing a category archive
  • is_category(‘3’) : returns true if viewing the archive of the category with the id 3
  • is_category(‘People and society’): return true if viewing the archive of the category with the name People and society
  • is_category(‘people-society’): return true if viewing the archive of the category with the slug people-society

These are the most used and you can find a lot more on the WordPress Codex.