Encode Hex

Encode-Hex.ps1

<#
.SYNOPSIS
    This script provides three modes of operation:
    1. Converts a given string to its hexadecimal representation.
    2. Decodes a given hexadecimal string back to its original UTF-8 representation.
    3. Renames files in a given directory by encoding the part of the filename before the first '.' or '_'.

.PARAMETER InputString
    A string that will be converted to hexadecimal encoding.

.PARAMETER EncodedString
    A hexadecimal encoded string that will be decoded back to its original UTF-8 representation.

.PARAMETER Directory
    The directory containing files to be renamed.

.PARAMETER Pattern
    A wildcard pattern to filter files for renaming. Defaults to '*'.

.PARAMETER WhatIf
    If specified, renaming will not be performed but the renaming actions will be logged.

.DESCRIPTION
    If an InputString is provided, it is converted to hexadecimal encoding and outputted.
    If an EncodedString is provided, it is decoded from hexadecimal and outputted in its UTF-8 representation.
    If a Directory is provided, files matching the specified pattern are renamed, encoding the portion of the filename before the first '.' or '_'.
    If -WhatIf is specified, renaming will not be performed but the changes will be logged.

.EXAMPLE
    .\Encode-Hex.ps1 -InputString "Hello, World!"
    Outputs the hexadecimal encoded representation of "Hello, World!".

.EXAMPLE
    .\Encode-Hex.ps1 -EncodedString "48656C6C6F2C20576F726C6421"
    Outputs the decoded UTF-8 representation of "Hello, World!".

.EXAMPLE
    .\Encode-Hex.ps1 -Directory "C:\path\to\directory" -Pattern "*.xls"
    Renames all .xls files in the specified directory, encoding the first part of each filename.

.EXAMPLE
    .\Encode-Hex.ps1 -Directory "C:\path\to\directory" -Pattern "*.xls" -WhatIf
    Logs all renaming operations without actually renaming the files.

    .EXAMPLE
    @("apple", "banana", "cherry") | ForEach-Object {
        [PSCustomObject]@{
            Original = $_
            Transformed = .\Encode-Hex.ps1 -InputString $_
            Check = .\Encode-Hex.ps1 -EncodedString (.\Encode-Hex.ps1 -InputString $_) 
        }
    } | Format-Table -AutoSize 
    Encode array of objects and display in table
#>

param (
    [string]$InputString,
    [string]$EncodedString,
    [string]$Directory,
    [string]$Pattern = "*",
    [switch]$WhatIf
)

function Convert-ToHex([string]$InputString) {
    $bytes = [System.Text.Encoding]::UTF8.GetBytes($InputString)
    return ($bytes | ForEach-Object { "{0:X2}" -f $_ }) -join ""
}

function Convert-FromHex([string]$EncodedString) {    
    $bytes = for ($i = 0; $i -lt $EncodedString.Length; $i += 2) { [Convert]::ToByte($EncodedString.Substring($i, 2), 16) }
    return [System.Text.Encoding]::UTF8.GetString($bytes)
}

if ($InputString) {
    Convert-ToHex -InputString $InputString | Write-Output
}
elseif ($EncodedString) {
    Convert-FromHex -EncodedString $EncodedString | Write-Output
}
elseif ($Directory) {
    $currentDir = Get-Location

    Get-ChildItem -Path $Directory -Filter $Pattern | Where-Object { !$_.PSIsContainer } | ForEach-Object {        
        if ($_.BaseName -match "^([^._]+)(.*)") {            
            $encodedPart = Convert-ToHex -InputString $matches[1]
            $newName = $encodedPart + $matches[2] + $_.Extension
            $newPath = Join-Path $_.DirectoryName $newName
            
            $originalName = [System.IO.Path]::GetRelativePath($currentDir.Path, $_.FullName)
            $newPathRelative = [System.IO.Path]::GetRelativePath($currentDir.Path, $newPath)

            Write-Host ("{0,-30}" -f $originalName) -NoNewline
            Write-Host ">>" -ForegroundColor Red -NoNewline
            Write-Host " $newPathRelative"
            
            if (-not $WhatIf) {
                Rename-Item -Path $_.FullName -NewName $newPath
            }
        }
    }
}
else {
    Write-Output "Please provide a string to encode, a hexadecimal string to decode, or a directory path to process files."
}

Encode.java

public static String hexToUtf8(String hex) {
        if (hex.length() % 2 != 0) {
            throw new IllegalArgumentException("Hex string must have an even length");
        }

        byte[] bytes = new byte[hex.length() / 2];
        for (int i = 0; i < hex.length(); i += 2) {
            bytes[i / 2] = (byte) Integer.parseInt(hex.substring(i, i + 2), 16);
        }

        return new String(bytes, StandardCharsets.UTF_8);
    }

    public static String utf8ToHex(String utf8) {
        StringBuilder hex = new StringBuilder();
        byte[] bytes = utf8.getBytes(StandardCharsets.UTF_8);
        for (byte b : bytes) {
            hex.append(String.format("%02X", b));
        }
        return hex.toString();
    }