From the wiki,

In computing, data storage, and data transmission, character encoding is used to represent a repertoire of characters by some kind of encoding system that assigns a number to each character for digital representation.

Okay, they mean converting character to some number for storing and transmitting data.

There are two popular character sets

1. ASCII
   1. American Standard Code for Information Interchange
   2. Pretty much all the characters and symbols in modern keyboard comes under ASCII
   3. Total of 128 characters
   4. Decimal value between 65 and 90 represents captial alphabets and 97 to 122 represents small alphabets
2. UTF-8
   1. ASCII doesn’t cover characters from other languages.
   2. UTF-8 is capable of encoding all 1,112,064 valid character code points in Unicode using one to four one-byte (8-bit) code units.
   3. It has backward compatible with ASCII

I run into character set in postgres. There is client_encoding and server_encoding setting.

There are two types of variable declaration.

1. recursively expanded variables - foo is assigned with bar which inturns assigned to ugh whose value is Huh?

foo = $(bar)
bar = $(ugh)
ugh = Huh?

all:;echo $(foo)

$ make
$ Huh?

2. simply expanded variables - foo is assigned with bar however bar is not defined yet. so it outputs to nothing.

foo := $(bar)
bar := $(ugh)
ugh := Huh?

all:;echo $(foo)

$ make
$

NOTE: To echo something it needs to be in a target. Here the target name is all.

This is a crosspost from my TIL

What the heck is .PHONY in makefile? I have seen this for so long but I always shrugged off. Whatever that is. Well, finally I decided to learn about it.

A bit of introduction to Makefile syntax.

target: prerequisites
<TAB> recipe

The first target in a Makefile will be executed by default when we call make.

blah: blah.o
    cc blah.o -o blah # Runs third

blah.o: blah.c
    cc -c blah.c -o blah.o # Runs second

blah.c:
    echo "int main() { return 0; }" > blah.c # Runs first

In the above example, blah, blah.o and blah.c are targets and they are all files.