<#
.Synopsis
Check file header if it is a JPG file
.EXAMPLE
Check one file:
Test-JPGHeader -File c:\temp\myPicture.jpg
.EXAMPLE
Check all jpeg files in one folder
(ls c:\pictures\*.jpg ).FullName | % {if ((Test-JPGHeader -File $_) -eq $false) {Write-Host "$_ is not real JPG"}}
.NOTES
If file doesn't exists, function returns false
#>
Function Test-JPGHeader {
Param
([Parameter(Mandatory=$true, Position=0)] [String]$File)
$Result = $false
if ((Test-Path $File) -eq $false) {
Return $Result
Break;
}
[String]$JPG = "255216255"
[Byte[]]$RAWHeader = Get-Content $File -TotalCount 3 -Encoding Byte
[String]$Header += $RAWHeader
$Header = $Header.Replace(" ","")
$Result = $JPG -contains $Header
Return $Result
}