File types are not entirely dependent on file extension. Rather, binary files have internal ID numbers called "magic numbers" that tell Windows what type of file it is. Here is a function to read and display the magic number:
function Get-MagicNumber ($path)
{ Resolve-Path $path | Foreach-Object {
$magicnumber = Get-Content -encoding byte $_ -read 4 -total 4
$hex1 = ("{0:x}" -f ($magicnumber[0] * 256 + $magicnumber[1])).PadLeft(4, "0")
$hex2 = ("{0:x}" -f ($magicnumber[2] * 256 + $magicnumber[3])).PadLeft(4, "0")
[string] $chars = $magicnumber| %{ if ([char]::IsLetterOrDigit($_))
{ [char] $_ } else { "." }}
"{0} {1} '{2}'" -f $hex1, $hex2, $chars }
}
{ Resolve-Path $path | Foreach-Object {
$magicnumber = Get-Content -encoding byte $_ -read 4 -total 4
$hex1 = ("{0:x}" -f ($magicnumber[0] * 256 + $magicnumber[1])).PadLeft(4, "0")
$hex2 = ("{0:x}" -f ($magicnumber[2] * 256 + $magicnumber[3])).PadLeft(4, "0")
[string] $chars = $magicnumber| %{ if ([char]::IsLetterOrDigit($_))
{ [char] $_ } else { "." }}
"{0} {1} '{2}'" -f $hex1, $hex2, $chars }
}
Executables use the two letters "MZ" (which coincidentally are the initials of Mark Zbikowski, one of the original developers of MS DOS). Data files use different signatures.
