Combine multiple text files into one

Combine-TextFiles.ps1

function Write-Title{
    param([string]$Title)
    Clear-Host
    Write-Host
    Write-Host "  -- $Title --"
    Write-Host
}

function Get-Path{
    param([string]$Prompt, [string]$DefaultValue)
    Write-Host $Prompt
    Write-Host " Default [$DefaultValue]"
    Do{
        $target = Read-Host -Prompt '  '
        if ($target -eq ''){
            $target = $DefaultValue
            Write-Host
            $target
            Break
        }
        elseif ((Test-Path $target -PathType Container) -eq $false){
            Write-Host "      Error: Invalid path"
            Write-Host
        }
        else{
            Write-Host
            $target
            Break
        }
    }
    Until($false)
}

function Get-FileName{
    param([string]$Prompt, [string]$DefaultValue)
    Write-Host $Prompt
    Write-Host " Default [$DefaultValue]"
    Do{
        $target = Read-Host -Prompt '  '
        if ($target -eq ''){
            $target = $DefaultValue
        }
        if(Test-ValidFileName $target){
            Write-Host
            $target
            Break
        }
        else{
            Write-Host "      Error: Invalid file name"
            Write-Host
        }
  
    }
    Until($false)
}

function Test-ValidFileName
{
    param([string]$FileName)

    $IndexOfInvalidChar = $FileName.IndexOfAny([System.IO.Path]::GetInvalidFileNameChars())

    # IndexOfAny() returns the value -1 to indicate no such character was found
    if($IndexOfInvalidChar -eq -1)
    {
        return $true
    }
    else
    {
        return $false
    }
}

function Get-Flag{
    param([string]$Prompt, [string]$DefaultValue)
    Write-Host $Prompt
    Write-Host " Default [$DefaultValue]"
    Do{
        $target = Read-Host -Prompt '  '
        if(($target.ToLower() -eq 'n') -or ($target.ToLower() -eq 'no') -or ($target.ToLower() -eq 'false')){
            Write-Host
            return $false
        }
        elseif(($target.ToLower() -eq '') -or ($target.ToLower() -eq 'y') -or ($target.ToLower() -eq 'yes') -or ($target.ToLower() -eq 'true')) {
            Write-Host
            return $true
        }
    }Until($false)
        
    
}


# Get Started
Write-Title "Combine-TextFiles"

# Get the folder to look in
$target = Get-Path 'Specify a target directory containing text files' $PSScriptRoot

# Get the path to use for output
#$outPath = Get-Path 'Specify a directory for output' ($env:HOMEDRIVE+$env:HOMEPATH+'\Documents')
$outPath = Get-Path 'Specify a directory for output' $PSScriptRoot

# Get the file name to output
$outFile = Get-FileName 'Specify a name for the output file' 'combined.txt'

# See if we want to output file names in the summary
$flag = Get-Flag 'Include file names in output? y/n' 'y'

# Combine the output path and filename
$outputFile = $outPath+'\'+$outFile

# When the file already exists, delete it
if(Test-Path $outFile -PathType Leaf){
    Remove-Item -Force $outFile
}

# Loop over each item, add the item name to the file then the content
Get-ChildItem $target -Filter *.txt | 
Foreach-Object {
    if($flag -eq $true){
      Add-Content -Path $outputFile -Value ('File: ' + $_.Name)
    }
    Get-Content $_.FullName | Add-Content -Path $outputFile

}

Write-Host " - Done -"
Write-Host "  Combined [$target]"
Write-Host "  Into [$outputFile]"
Write-Host
Read-Host -Prompt 'Press any key to exit . . .  '