Mass-validate all Steam games on Windows

Validate-Steam-Games.ps1

########################################################################################################################
# Mass Steam Game Validator
#
# This script, meant to be used on Windows, validates whole Steam libraries. By default, Steam client can only do it
# one-by-one which is cumbersome in larger libraries. This tool uses the Valve's official steamCMD.
# The tool, by default, will attempt to validate all games in all libraries found, using the default account. Use -Help
# to see available options.
#
# To run this tool, save it as ".ps1" file, start Windows PowerShell/Windows Terminal, and type
# .\Validate-Steam-Games.ps1 in the console. You may need to enable PS scripts (https://superuser.com/a/106362) first.
#
# License: MIT; (c) Gregory House (https://github.com/kiler129)

param (
    [switch]$DryRun,
    [string]$Skip,
    [switch]$Help,
    [string]$LibraryPath,
    [string]$User,
    [switch]$Verbose
)

# --- Help ---
if ($Help) {
    $scriptName = $MyInvocation.MyCommand.Name
    Write-Host "Mass Steam Game Validator" -ForegroundColor Yellow
    Write-Host ""
    Write-Host "USAGE:" -ForegroundColor Cyan
    Write-Host "  .\$scriptName [-DryRun] [-Skip <AppIDs>] [-LibraryPath <Path>] [-User <Name>] [-Verbose] [-Help]" -ForegroundColor White
    Write-Host ""
    Write-Host "OPTIONS:" -ForegroundColor Cyan
    Write-Host "  -DryRun              Verifies Steam login and lists games, but does not validate them." -ForegroundColor White
    Write-Host "  -Skip <IDs>          Comma-separated AppIDs to skip (e.g. -Skip 346110,123456)." -ForegroundColor White
    Write-Host "  -LibraryPath <Path>  Use a specific Steam library root (folder containing 'steamapps')." -ForegroundColor White
    Write-Host "                       If omitted, libraries are auto-detected from registry and libraryfolders.vdf." -ForegroundColor White
    Write-Host "  -User <Name>         Steam username to use. If omitted, auto-detected from loginusers.vdf (or prompted)." -ForegroundColor White
    Write-Host "  -Verbose             Echo the exact steamcmd command and stream its live output." -ForegroundColor White
    Write-Host "  -Help                Show this help screen and exit." -ForegroundColor White
    exit
}

# --- Parse Skip list ---
$skipList = @()
if ($Skip) {
    $skipList = $Skip.Split(",") | ForEach-Object { $_.Trim() } | Where-Object { $_ }
    if ($skipList.Count) { Write-Host "[INFO] Will skip AppIDs: $($skipList -join ', ')" -ForegroundColor Yellow }
}

# --- Steam install path ---
$steamReg = Get-ItemProperty -Path "HKCU:\Software\Valve\Steam" -ErrorAction SilentlyContinue
if (-not $steamReg -or -not $steamReg.SteamPath) {
    Write-Host "[ERROR] Could not find Steam in registry." -ForegroundColor Red
    $steamPath = Read-Host "Enter your Steam install path (e.g. C:\Program Files (x86)\Steam)"
} else {
    $steamPath = $steamReg.SteamPath
}
$libraryFile    = Join-Path $steamPath "steamapps\libraryfolders.vdf"
$loginUsersFile = Join-Path $steamPath "config\loginusers.vdf"

# --- Detect usernames from loginusers.vdf ---
function Detect-SteamUsers {
    $users = @()
    if (Test-Path -LiteralPath $loginUsersFile) {
        $content = Get-Content -LiteralPath $loginUsersFile -Raw
        $rx = '"AccountName"\s*"([^"]+)"'
        $matches = [regex]::Matches($content, $rx)
        foreach ($m in $matches) { $users += $m.Groups[1].Value }
    }
    $users | Where-Object { $_ -and $_.Trim() -ne '' } | Select-Object -Unique
}
$detectedUsers = Detect-SteamUsers

# --- Resolve steamcmd ---
function Resolve-SteamCmd {
    $cmd = Get-Command steamcmd -ErrorAction SilentlyContinue
    if ($cmd) {
        Write-Host "[INFO] Found steamcmd in PATH." -ForegroundColor Green
        return "steamcmd"
    }

    Write-Host "[ERROR] steamcmd not found in PATH." -ForegroundColor Red
    if (Get-Command winget -ErrorAction SilentlyContinue) {
        Write-Host "Install it with:" -ForegroundColor Cyan
        Write-Host "    winget install steamcmd" -ForegroundColor White
    } else {
        Write-Host "Download: https://developer.valvesoftware.com/wiki/SteamCMD" -ForegroundColor Cyan
    }

    $choice = Read-Host "Do you want to manually enter the path now? (Y/N)"
    if ($choice -notmatch '^[Yy]$') { throw "steamcmd is required but not installed or provided." }

    while ($true) {
        $candidate = Read-Host "Enter full path to steamcmd.exe (or Ctrl+C to cancel)"
        if ([string]::IsNullOrWhiteSpace($candidate)) { Write-Host "[WARN] Path cannot be empty." -ForegroundColor Yellow; continue }
        $candidate = $candidate.Trim('"')
        if (-not (Test-Path -LiteralPath $candidate)) { Write-Host "[ERROR] File not found: $candidate" -ForegroundColor Red; continue }
        try {
            & $candidate +quit | Out-Null
            if ($LASTEXITCODE -eq 0) { Write-Host "[INFO] steamcmd verified at: $candidate" -ForegroundColor Green; return $candidate }
            Write-Host "[ERROR] steamcmd exited with code $LASTEXITCODE when tested." -ForegroundColor Red
        } catch { Write-Host "[ERROR] Failed to run steamcmd: $($_.Exception.Message)" -ForegroundColor Red }
    }
}

# --- Resolve username ---
function Resolve-SteamUser {
    param([string]$UserOverride, [string[]]$Detected)

    if (-not [string]::IsNullOrWhiteSpace($UserOverride)) {
        Write-Host "[INFO] Using specified Steam user: $UserOverride" -ForegroundColor Green
        return $UserOverride
    }
    if ($Detected.Count -eq 1) {
        Write-Host "[INFO] Auto-detected Steam user: $($Detected[0])" -ForegroundColor Green
        return $Detected[0]
    }
    if ($Detected.Count -gt 1) {
        Write-Host "[INFO] Multiple Steam users detected:" -ForegroundColor Yellow
        for ($i = 0; $i -lt $Detected.Count; $i++) {
            Write-Host " [$i] $($Detected[$i])"
        }
        while ($true) {
            $choice = Read-Host "Select user number"
            if ($choice -match '^\d+$' -and [int]$choice -ge 0 -and [int]$choice -lt $Detected.Count) {
                $selected = $Detected[[int]$choice]
                Write-Host "[INFO] Selected Steam user: $selected" -ForegroundColor Green
                return $selected
            }
            Write-Host "[WARN] Invalid choice, try again." -ForegroundColor Yellow
        }
    }
    Write-Host "[WARN] No Steam usernames detected in loginusers.vdf." -ForegroundColor Yellow
    $manual = Read-Host "Enter your Steam username"
    Write-Host "[INFO] Using manually entered Steam user: $manual" -ForegroundColor Green
    return $manual
}

# --- Test login (interactive always) ---
function Test-SteamLogin {
    param([string]$SteamCmdPath, [string]$SteamUser, [switch]$Verbose)

    Write-Host "[INFO] Testing Steam login for user '$SteamUser'..." -ForegroundColor Cyan
    Write-Host "       If cached credentials are missing, SteamCMD will ask for your password/Steam Guard." -ForegroundColor Yellow
    Write-Host "       This prompt is from the official Steam tool, not from this script." -ForegroundColor Yellow

    $args = @("+login", $SteamUser, "+quit")
    if ($Verbose) { Write-Host "[VERBOSE] Executing: $SteamCmdPath $($args -join ' ')" -ForegroundColor Magenta }

    & $SteamCmdPath @args
    $exit = $LASTEXITCODE

    if ($exit -eq 0) {
        Write-Host "[INFO] Steam login successful." -ForegroundColor Green
    } else {
        Write-Host "[ERROR] Steam login failed with exit code $exit." -ForegroundColor Red
        throw "Steam login failed. Cannot proceed."
    }
}

# --- Steam libraries (return roots, not steamapps) ---
function Get-SteamLibraries {
    param([string]$ManualPath)

    if ($ManualPath) { return ,$ManualPath }

    $libs = New-Object System.Collections.Generic.List[string]
    $libs.Add($steamPath)

    if (Test-Path -LiteralPath $libraryFile) {
        $content = Get-Content -LiteralPath $libraryFile
        foreach ($line in $content) {
            if ($line -match '"path"\s+"(.+)"') {
                $raw = $matches[1] -replace '\\\\','\'
                try {
                    $resolved = (Resolve-Path $raw -ErrorAction SilentlyContinue)
                    if ($resolved) {
                        $libs.Add($resolved.Path)
                    } else {
                        $libs.Add($raw)
                    }
                } catch { $libs.Add($raw) }
            }
        }
    }

    $libs | ForEach-Object { $_.ToLowerInvariant() } | Sort-Object -Unique | ForEach-Object {
        try { (Resolve-Path $_).Path } catch { $_ }
    }
}

# --- Parse manifest for name and installdir ---
function Get-AppInfoFromManifest($manifestPath) {
    $name = "<Unknown>"
    $installdir = $null
    try {
        $hitName = Select-String -Path $manifestPath -Pattern '"name"\s+"([^"]+)"' -ErrorAction SilentlyContinue | Select-Object -First 1
        if ($hitName -and $hitName.Matches.Count -gt 0) { $name = $hitName.Matches[0].Groups[1].Value }
        $hitDir = Select-String -Path $manifestPath -Pattern '"installdir"\s+"([^"]+)"' -ErrorAction SilentlyContinue | Select-Object -First 1
        if ($hitDir -and $hitDir.Matches.Count -gt 0) { $installdir = $hitDir.Matches[0].Groups[1].Value }
    } catch {}
    [PSCustomObject]@{ Name = $name; InstallDir = $installdir }
}

# --- Validate one game at its real install path ---
function Validate-App([string]$appId, [string]$gameName, [string]$installPath) {
    if ($skipList -contains $appId) { Write-Host "[SKIP] $appId ($gameName)" -ForegroundColor DarkYellow; return }
    if ($DryRun) { Write-Host "[DRYRUN] Would validate $appId ($gameName) at [$installPath]" -ForegroundColor DarkCyan; return }

    if (-not (Test-Path -LiteralPath $installPath)) {
        Write-Host "[WARN] Install path not found, creating (SteamCMD may re-download): $installPath" -ForegroundColor Yellow
        New-Item -ItemType Directory -Force -Path $installPath | Out-Null
    }

    $args = @(
        "+force_install_dir", $installPath,
        "+login", $steamUser,
        "+app_update", $appId, "validate",
        "+quit"
    )

    Write-Host "[INFO] Validating $appId ($gameName) at [$installPath]..." -ForegroundColor Cyan
    if ($Verbose) { Write-Host "[VERBOSE] Executing: $steamCmdPath $($args -join ' ')" -ForegroundColor Magenta }

    & $steamCmdPath @args
    if ($LASTEXITCODE -eq 0) { Write-Host "[SUCCESS] $gameName validated." -ForegroundColor Green }
    else { Write-Host "[ERROR] $gameName failed with code $LASTEXITCODE." -ForegroundColor Red }
}

# --- Main ---
Write-Host "=======================================" -ForegroundColor Yellow
Write-Host ("Mass Steam Game Validation {0} Started: {1}" -f ($(if ($DryRun) {"(DRY RUN)"} else {""}), (Get-Date))) -ForegroundColor Yellow
Write-Host "=======================================" -ForegroundColor Yellow
Write-Host "NOTE: Validation checks files and only re-downloads missing/corrupted ones, not full reinstall." -ForegroundColor Yellow

$steamCmdPath = Resolve-SteamCmd
$steamUser    = Resolve-SteamUser -UserOverride $User -Detected $detectedUsers
Test-SteamLogin -SteamCmdPath $steamCmdPath -SteamUser $steamUser -Verbose:$Verbose

$libraries = Get-SteamLibraries -ManualPath $LibraryPath
foreach ($libRoot in $libraries) {
    $steamapps = Join-Path $libRoot "steamapps"
    if (-not (Test-Path -LiteralPath $steamapps)) {
        Write-Host "[WARN] No 'steamapps' in library: $libRoot" -ForegroundColor Yellow
        continue
    }

    Write-Host "[LIB] $libRoot" -ForegroundColor DarkYellow

    Get-ChildItem -LiteralPath $steamapps -Filter "appmanifest_*.acf" -ErrorAction SilentlyContinue |
        ForEach-Object {
            if ($_.Name -match "appmanifest_(\d+).acf") {
                $appId = $matches[1]
                $info  = Get-AppInfoFromManifest $_.FullName
                $gameName   = $info.Name
                $installdir = $info.InstallDir

                if ([string]::IsNullOrWhiteSpace($installdir)) {
                    Write-Host "[WARN] Manifest missing 'installdir' for AppID $appId; skipping to avoid mis-install." -ForegroundColor Yellow
                    return
                }

                $installPath = Join-Path (Join-Path $libRoot "steamapps\common") $installdir
                Validate-App $appId $gameName $installPath
            }
        }
}

Write-Host "=======================================" -ForegroundColor Yellow
Write-Host "Validation Completed: $(Get-Date)" -ForegroundColor Yellow
Write-Host "=======================================" -ForegroundColor Yellow

@bickford I actually had this issue before and it was related to the script seeing a different install dir than the Steam GUI vs SteamCMD. I will have some time next week to look into that, as probably there's some edge case, or the SteamCMD intepretation changed.

Thanks @kiler129 - let me know if you need help testing.

I've not been fast to respond on Github lately due to the time of year (and am away the next week), but when I'm back I generally respond in a day or two and would be glad to help test against a different config for you.
Cheers