How to know whether a file's encoding is ansi or utf8?

[Alexandre via Digitalmars-d-learn]

Read the BOM ?

module main;

import std.stdio;

enum Encoding
{
	UTF7,
	UTF8,
	UTF32,
	Unicode,
	BigEndianUnicode,
	ASCII
};

Encoding GetFileEncoding(string fileName)
{
	import std.file;
	auto bom = cast(ubyte[]) read(fileName, 4);

	if (bom[0] == 0x2b && bom[1] == 0x2f && bom[2] == 0x76)
		return Encoding.UTF7;
	if (bom[0] == 0xef && bom[1] == 0xbb && bom[2] == 0xbf)
		return Encoding.UTF8;
	if (bom[0] == 0xff && bom[1] == 0xfe)
		return Encoding.Unicode; //UTF-16LE
	if (bom[0] == 0xfe && bom[1] == 0xff)
		return Encoding.BigEndianUnicode; //UTF-16BE
	if (bom[0] == 0 && bom[1] == 0 && bom[2] == 0xfe && bom[3] == 
0xff)
		return Encoding.UTF32;

	return Encoding.ASCII;
}

void main(string[] args)
{
	if(GetFileEncoding("test.txt") == Encoding.UTF8)
		writeln("The file is UTF8");
	else
		writeln("File is not UTF8 :(");
}



On Tuesday, 22 July 2014 at 09:50:00 UTC, Sam Hu wrote:
> Greetings!
>
> As subjected,how can I know whether a file is in UTF8 encoding 
> or ansi?
>
> Thanks for the help in advance.
>
> Regards,
> Sam