f.write(0xEF.chr) What is 0xEF?

[SookyLala]

Afternoon, would someone be able to point me in the right direction.

I'm reading some scripts from Pokemon Essentials, specifically how they go about reading/writing from their text files.

I've come across this a lot

def pbWriteDefaultTypes
  if !safeExists?("PBS/types.txt")
    File.open("PBS/types.txt","w"){|f|
      f.write(0xEF.chr)
      f.write(0xBB.chr)
      f.write(0xBF.chr)
fx=<<END
[0]
Name=Normal
InternalName=NORMAL
Weaknesses=FIGHTING
Immunities=GHOST

I tried to look it up and I came across ASCII and UTF-8 but it doesn't seem to match.

Do you know of any tutorials or links that would help me understand what is going on there?

 

[IceDragon]

That would a byte order mark, https://en.wikipedia.org/wiki/Byte_order_mark

 

[SookyLala]

That would a byte order mark, https://en.wikipedia.org/wiki/Byte_order_mark

Great, thank you very much.