Monitor your Zwift log file and outputs the latest Ride On

latest_rideon.ps1

# Copyright 2020 Jonas Häggqvist <rasher@rasher.dk>
#
# Usage of the works is permitted provided that this instrument is retained with the
# works, so that any entity that uses the works is notified of this instrument.
#
# DISCLAIMER: THE WORKS ARE WITHOUT WARRANTY.


# This script monitors your Zwift log file and outputs the latest Ride On to a given
# output file. The output file is updated at most every N ms (6000), to try and follow
# the Zwift GUI.
# 
# Possible bug: If the log file is truncated or becomes smaller in any way, Powershell
# appears to panic and start outputting the entire file. Not sure there's any way to
# prevent that. May be fixed in new PowerShell versions? Written/tested on 5.1. It
# should not happen anyway unless Zwift does something really weird. This of course
# means it will.

$docs = [environment]::GetFolderPath("MyDocuments")
$zwift = "$docs\Zwift"                  # Zwift data directory
$log = "$zwift\Logs\Log.txt"            # Path to Zwift log file
$output = "$zwift\Logs\LastRideon.txt"  # File to write output to
$delay = 6000                           # Delay in ms between updates of the file
$prefix = ""                            # Added in the logfile in front of the username
$postfix = " says Ride On!"             # Added after the username

Function Write-SlowOutput {
[CmdletBinding()]
param (
    [Parameter(Mandatory=$true,
                HelpMessage="How long to pause for (ms)")]
    [int32]$waitFor,
    [Parameter(Mandatory=$false,
                HelpMessage="File to output to")]
    [string]$outputFile,
    [Parameter(ValueFromPipeline)]
    [Object]$input
)
BEGIN {}
PROCESS {
    Write-Host $input
    if ($outputFile) {
        Out-File -Append -Encoding UTF8 -FilePath $outputFile -InputObject $input
    }
    Start-Sleep -Milliseconds $waitFor
}
END {}

}

Get-Content -Tail 0 -Wait -Encoding "UTF8" $log | 
  Select-String "HUD_Notify: (.*) says Ride On!" |
   % {$prefix + $_.matches.groups[1].value} |
    Write-SlowOutput -outputFile $output -waitFor $delay

Test run: https://streamable.com/t2ot7r