Let us start by first asking the question, of why do we need, the processor modes. Well simply put, a processor mode, is used to define a capability, so for example, the kind of features, instructions, or registers which … Read More
What is unicode, utf-8 , utf-16 and utf-32 ?
What is unicode ?
– what is a string? what is text? you might ask!
– A collection of characters?
– good guess.
– and a character is ?
– any human readable one, as in ¥, or … Read More
Characters in swift a tutorial
What is a character ?
Nowadays, what is accepted, is that a character has a code point, an encoding, and that it belongs, to a character set.
A character-set, can specify both the code points, and the encoding, or it … Read More
Optionals in swift a tutorial
In some languages other than swift, a variable or a constant, can or cannot have a value. So a variable or a constant, can be null, if no value was assigned to them, or if set to null.
What … Read More
What is core foundation?
A little bit of history
To understand what core foundation is, let us get back in history a little bit. It was the year 2000, and there were two ways to develop applications, for macOS 10.
On one hand, … Read More
What is NSObject ?
Many object oriented programming languages, have a class, from which all other classes extends.
In general, a class has a set of methods, and variables, which it defines. The variables being the data, and the methods, being the … Read More
How to list windows, and their information, under Microsoft windows, Linux and macOS
A window is just a place, where an application can do its drawing, like drawing a button, text or other stuff.
For Linux
On Linux or UNIX like systems, there is a tool called xwininfo, which can be … Read More
xprop a tutorial
Let us start by defining what is xprop. xprop is simply a tool, to query, set, and remove the properties of an X11 window .
Additionally, using xprop, you can query X11 core fonts attributes, so you … Read More
What is a property in X11?
In X11, a property simply has a name, a type, a format, a value, and is associated with a window.
There is a set of functions, provided by X11, which allows manipulating a property, and they … Read More
What is an atom in X11?
An atom in X11, is of type Atom, which is defined in the <X11/Xatom.h header, as :
typedef unsigned long Atom; /* Also in Xdefs.h */
An atom is 32 bits, the reason, that long was chosen, … Read More