Function for writing to a log file in plain format, with the option to write the information to the host as well

Write-SimpleLog.ps1 [2026.04.27]

[CmdletBinding(SupportsShouldProcess)]
param()

#region FUNCTIONS
function New-SimpleLog
{
    <#
    .SYNOPSIS
        Write information to a log file and optionally to the console
    .LINK
        https://gist.github.com/dancing-groot/6af20a68e67306762905665db339d30d
    .NOTES
        Version:    2026.03.27
        Author:     @dancing-groot
    #>
    [cmdletbinding(SupportsShouldProcess)]
    param (
        [string]$LogFile = "$($ENV:TEMP)\$((Split-Path -Leaf $script:MyInvocation.MyCommand.Path).Trim('.ps1'))-$(Get-Date -UFormat '%Y.%m.%d')-$(Get-Date -UFormat '%H%M').log",

        [ValidateSet('Log', 'Console', 'All')]
        [string]$WriteTo = "Log"
    )

    if ($script:PSBoundParameters['Verbose']) { $script:VerbosePreference = 'Continue' }
    if ($script:PSBoundParameters['Debug']) { $script:DebugPreference = 'Continue' }

    if ($WriteTo -in @('Log', 'All'))
    {
        # This can break within scheduled tasks
        $LogFile = $LogFile.Replace("\\", "\")
        if ((Test-Path -LiteralPath (Split-Path $LogFile -Parent)) -eq $false) { New-Item -Path (Split-Path $LogFile -Parent) -Type Directory | Out-Null }
    } else {
        $LogFile = $null
    }

    # If -WhatIf is called for this function, pass it on to Write-SimpleLog
    # E.g. you may be running the script with -WhatIf, but if you still need to write to the console and/or log use
    # New-SimpleLog [parameters] -WhatIf:$false
    return @{Path = $LogFile; WriteTo = $WriteTo; WhatIf = (-not $PSCmdlet.ShouldProcess("Write Log")) }
} # New-SimpleLog

function Write-SimpleLog
{
    <#
    .SYNOPSIS
        Write information to a log file and optionally to the console
    .LINK
        https://gist.github.com/dancing-groot/6af20a68e67306762905665db339d30d
    .NOTES
        Version:    2026.04.27
        Author:     @dancing-groot
    #>
    [cmdletbinding(SupportsShouldProcess)]
    param (
        [string]$Path,

        #[parameter(Mandatory = $true)]
        [string]$Message,

        [ValidateSet('Warning', 'Error', 'Verbose', 'Debug', 'Info')] 
        [string]$Type = "Info",

        [ValidateSet('Log', 'Console', 'All')]
        [string]$WriteTo = "Log"
    )

    try
    {
        $content = "[$(Get-Date -UFormat '%Y.%m.%d %T')]  $($Type.ToUpper())".PadRight(30) + "  $Message"

        # Write the line to the log file
        switch ($true)
        {
            ($WriteTo -in @('Console', 'All'))
            {
                switch ($type)
                {
                    "Info" { Write-Information $Message -InformationAction Continue; break }
                    "Warning" { Write-Warning $Message -WarningAction Continue; break }
                    "Error" { Write-Host "ERROR: $Message" -ForegroundColor Red; break }
                    "Verbose" { Write-Verbose $Message; break }
                    "Debug" { Write-Debug $Message; break }
                }
            }
            ($WriteTo -in @('Log', 'All'))
            {
                switch ($type)
                {
                    "Info" { Add-Content -LiteralPath $Path -Value $content -Encoding UTF8; break }
                    "Warning" { Add-Content -LiteralPath $Path -Value $content -Encoding UTF8; break }
                    "Error" { Add-Content -LiteralPath $Path -Value $content -Encoding UTF8; break }
                    "Verbose" { if ($script:PSBoundParameters['Verbose']) { Add-Content -LiteralPath $Path -Value $content -Encoding UTF8; break } }
                    "Debug" { if ($script:PSBoundParameters['Debug']) { Add-Content -LiteralPath $Path -Value $content -Encoding UTF8; break } }
                }
            }
        }
    }
    catch
    {
        Write-Output "$(Get-Date -UFormat '%Y.%m.%d %T')" + "`t" + "$Message"
    }
} # Write-SimpleLog
#endregion FUNCTIONS

#region DECLARATION
if ($PSBoundParameters['Debug']) { $DebugPreference = 'Continue' }

# --- Setup log file
$LogFile = "$PSScriptRoot\MyTestlog.log"
# Write to console and log if debugging
if ($PSBoundParameters['Debug'])
{
    $LogParams = New-SimpleLog -LogFile $LogFile -WriteTo All -WhatIf:$false
} else {
    $LogParams = New-SimpleLog -LogFile $LogFile -WriteTo Log -WhatIf:$false
}
# or use the line below to use the default values (a generated log file name in the user's TEMP folder and write to the log file only)
#$LogParams = New-SimpleLog
#endregion DECLARATION

#region TESTING
Write-SimpleLog @LogParams -Message "This is an Information message ✓"
Write-SimpleLog @LogParams -Message "This is a Debug message 🚧" -Type Debug
Write-SimpleLog @LogParams -Message "This is a Verbose message 📖" -Type Verbose
Write-SimpleLog @LogParams -Message "This is a Warning message ⚠️" -Type Warning
Write-SimpleLog @LogParams -Message "This is an Error message ✗" -Type Error
#region TESTING

2026.04.27
Added support for -WhatIf
If -WhatIf is called for this function, pass it on to Write-SimpleLog
E.g. you may be running the script with -WhatIf, but if you still need to write to the console and/or log use
New-SimpleLog [parameters] -WhatIf:$false

Added Unicode support
Text written is now forced as UTF8 with BOM to support unicode emojis.
Note that Configuration Manager Trace Log Tool will not show unicode characters.