gygon

# Eventlog monitoring script 2006/03/28 JonN
#
# Event logs can contain hundreds of thousands of items, so
# "get-eventlog System | where {<condition>}" can take excessively long
# on production systems.  Plus, the same failures will be reported
# over and over.
# This script will remember your last Index position in the log,
# and only report events which occurred since then.
# It also remembers the TimeGenerated of the oldest log entry,
# so that it can detect when the log has been cleared.
# Example:
# eventlog.msh1 -LogName System -Filter {$_.EventID -eq 4226} -PositionFile "c:\logs\syslogpos.txt"

param (
    [string]$LogName = "System",
    [ScriptBlock]$Filter = {$true},
    [string]$PositionFile = $home + "\" + $LogName + "_position.txt",
    [switch]$Force,
    [switch]$Restart
    )

write-debug "`$LogName = $LogName"
write-debug "`$Filter = '$Filter'"
write-debug "`$PositionFile = '$PositionFile'"
write-debug "`$Force = $Force"
write-debug "`$Restart = $Restart"

[int]$lastCheckedIndex = -1
[DateTime]$lastCheckedTime = [DateTime]::MaxValue

if (!$Restart)
{
    $filecontent = get-content $PositionFile -ea SilentlyContinue
    if ($null -eq $filecontent)
    {
        if (!$Force)
        {
      throw "Position file '$PositionFile' does not exist or could not be opened. Use -Force or -Restart to create a new position file."
        }
        write-verbose "Position file '$PositionFile' does not exist or could not be opened.  Rebuilding position file because -Force was specified."
    }
    else
    {
        write-debug "Position file contains '$filecontent'"
        trap {
            if ($Force)
            {
                write-warning "Content of position file '$PositionFile' is invalid.  Rebuilding position file because -Force was specified."
                $lastCheckedIndex = -1
                $lastCheckedTime = [DateTime]::MaxValue
                continue
            }
      throw "Content of position file '$PositionFile' is invalid.  Terminating operation.  Use -Force or -Restart to rebuild the position file."
        }
        # These lines will throw if the cast fails
        $lastCheckedIndex = $filecontent[0]
        $lastCheckedTime = $filecontent[1]
    }
}

write-debug "`$lastCheckedIndex = $lastCheckedIndex"
write-debug "`$lastCheckedTime = $lastCheckedTime"

# I don't simply call get-eventlog $LogName because I don't want to
# build an array with all the hundreds of thousands of event log entries.
# Instead, I make sure the EventLogEntryCollection is not unrolled.
$log = get-eventlog -List | where {$_.Log -ieq $LogName}
if ($null -eq $log)
{
    throw "Log not found: $LogName"
}

$entries = $log.Entries
if (0 -eq $entries.Count)
{
    write-debug "Log empty: $LogName"
    return
}

$oldestEntryTime = $entries[0].TimeGenerated
if ($oldestEntryTime -gt $lastCheckedTime)
{
    write-verbose "The log appears to have been cleared since it was last checked: $LogName."
    $lastCheckedIndex = -1
}

# The index can diverge from the number of entries
# when the log reaches its maximum size and is configured
# to "Overwrite entries as needed"
$newestEntryIndex = $entries[$entries.Count - 1].Index
$newestEntryTime = $entries[$entries.Count - 1].TimeGenerated

write-debug "Newest entry in log has index $newestEntryIndex"
write-debug "Newest entry in log has TimeGenerated $newestEntryTime"

# $entries.Count could be more than the maximum range "50000 .. 0"
foreach ($i in ($entries.Count - 1) .. 0)
{
    $entry = $entries[$i]
    if ($entry.Index -le $lastCheckedIndex) {
        break
    }
    # This line actually generates the output
    $entry | where $Filter
}

write-debug "Writing index $newestEntryIndex to position file '$PositionFile'"
write-debug "Writing time $newestEntryTime to position file '$PositionFile'"
$newestEntryIndex,$newestEntryTime | set-content $PositionFile

function Get-Web($url,
    [switch]$self,
    $credential,
    $toFile,
    [switch]$bytes)
{
    #.Synopsis
    #    Downloads a file from the web
    #.Description
    #    Uses System.Net.Webclient (not the browser) to download data
    #    from the web.
    #.Parameter self
    #    Uses the default credentials when downloading that page (for downloading intranet pages)
    #.Parameter credential
    #    The credentials to use to download the web data
    #.Parameter url
    #    The page to download (e.g. www.msn.com)    
    #.Parameter toFile
    #    The file to save the web data to
    #.Parameter bytes
    #    Download the data as bytes   
    #.Example
    #    # Downloads www.live.com and outputs it as a string
    #    Get-Web http://www.live.com/
    #.Example
    #    # Downloads www.live.com and saves it to a file
    #    Get-Web http://wwww.msn.com/ -toFile www.msn.com.html
    $webclient = New-Object Net.Webclient
    if ($credential) {
        $webClient.Credential = $credential
    }
    if ($self) {
        $webClient.UseDefaultCredentials = $true
    }
    if ($toFile) {
        if (-not "$toFile".Contains(":")) {
            $toFile = Join-Path $pwd $toFile
        }
        $webClient.DownloadFile($url, $toFile)
    } else {
        if ($bytes) {
            $webClient.DownloadData($url)
        } else {
            $webClient.DownloadString($url)
        }
    }
}

function SendEmail($SendTo,$SendSubject,$SendMessage)
{
    $SmtpClient = new-object system.net.mail.smtpClient
    $MailMessage = New-Object system.net.mail.mailmessage
    $SmtpClient.Host = "mail.plazahotelsuites.com"
    $FromAddress = new-object System.Net.Mail.MailAddress("sender@domain.com", "Sender Name")
    $mailmessage.sender = $FromAddress
    $mailmessage.from = $FromAddress
    $mailmessage.To.add($SendTo)
    $mailmessage.Subject = $SendSubject
    $mailmessage.IsBodyHtml = 1 

    # The line below will pull the message body from the specified file
    # This is currently commented out to include the file here so the Folio ID can be embedded
    # $mailmessage.Body = Get-Content .\emailbody.htm 

    $mailmessage.Body = $SendMessage

    $Credentials = new-object System.Net.networkCredential
    $Credentials.UserName = "sender@domain.com"
    $Credentials.Password = "password"
    $SMTPClient.Credentials = $Credentials
    $SMTPClient.Port = 25
    $smtpclient.Send($mailmessage)
}

# Set who the email goes to and what the subject will be.
$sendtoemail = 'user@domain.com'
$SendSubject = 'Message subject here'

$webpagecall = Get-Web 'http://www.somewebsite.com'
# Uncomment the line below to output the retrieved web page to the screen
# write $webpagecall
SendEmail $sendtoemail $SendSubject $webpagecall