PowerShell script to run a command as another user with saved credentials

run_as_with_saved_creds.ps1

# Usage:
#
# Call it without any args except path to file to save credential.
# The script will show a window for entering credentials and save them to a file in encrypted form.
# > powershell -File run_as_with_saved_creds.ps1 creds.txt
#
# Call it with arguments after path to file with saved credential.
# The script will execute the command as the user whose credentials have been saved in the file.
# > powershell -File run_as_with_saved_creds.ps1 creds.txt some commands and args

function QuotePathWithWhitespaces([string]$Path) {
    if ($Path -match '.*\s.*')
    { """$Path""" } else { $Path }
}

function GetAndSaveCredential([string]$Path) {
    $Credential = Get-Credential
    Set-Content `
        -Path $Path `
        @(
            $Credential.UserName,
            ($Credential.Password | ConvertFrom-SecureString)
        )
    $Credential
}

function LoadCredential([string]$Path) {
    $CredFileContent = Get-Content -Path $Path
    New-Object System.Management.Automation.PsCredential(
        $CredFileContent[0],
        ($CredFileContent[1] | ConvertTo-SecureString))
}

if ($args.Length -eq 0)
{
    "Specify path to credential file at first argument"
    exit
}

$CredPath = $args[0]

if ($args.Length -eq 1)
{
    GetAndSaveCredential($CredPath)
    exit
}

$args

$Credential = LoadCredential($CredPath)
$QuotedArgs = $args | Select-Object -Skip 2 | ForEach-Object { QuotePathWithWhitespaces($PSItem) }

$ps = Start-Process `
    -PassThru `
    -WindowStyle Hidden `
    -Credential $Credential `
    -FilePath $args[1] `
    -ArgumentList $QuotedArgs
$ps.WaitForExit()