ActiveXperts Network Monitor ships with a powerful set of pre-defined checks. Each individual check has a static number of configuration items. To monitor other items, or to combine monitoring items, you can make use of custom PowerShell checks.

Most of the built-in checks have a PowerShell equivalent, implemented as a PowerShell (.ps1) script file. Out-of-the-box, each PowerShell script monitors the same items as the built-in check. Feel free to modify the script.

To add a new PowerShell-based File Change monitoring check, do the following:

• On the 'Monitor menu', open 'New Monitoring Check (Script)' and choose 'New PowerShell Check'. The 'PowerShell Check' dialog box appears;
• In the 'Script File' selection box, select 'File-CheckFileChange.ps1';
• In the 'Script Parameters'group box enter the required parameters. You can also load a working sample first by clicking on the 'Click here to load a sample' link.

To customize the above monitoring check, click on the 'Edit button' next to the 'Script File' selection box. Notepad will be launched. You can now make changes to the PowerShell script.

File-CheckFileChange.ps1 script source code

#################################################################################
# ActiveXperts Network Monitor PowerShell script, (c) ActiveXperts Software B.V.
# For more information about ActiveXperts Network Monitor, visit the ActiveXperts 
# Network Monitor web site at https://www.activexperts.com
#################################################################################
# Script
#     File-CheckFileChange.ps1
# Description:
#     Checks if the specified file exists
# Parameters:
#     1) strPath - UNC formatted file path
#     2) strCredentials As String - Specify an empty string to use Metwork Monitor service credentials.
#         To use alternate credentials, enter a server that is defined in Server Credentials table.
#         (To define Server Credentials, choose Tools->Options->Server Credentials)' Usage:
# Usage:
#      .\File-CheckFileChange.ps1 '<\\Server\Share\Path>' '[altCredentials]'
# Sample:
#      .\File-CheckFileChange.ps1 '\\localhost\c$\windows\windowsupdate.log'
#################################################################################

# Parameters
param
  (
    [string]$strFileName,
    [string]$strAltCredentials
  )

cls


# Check paramters input
if ( [string]$strFileName -eq "" )
{
  echo "UNCERTAIN: Invalid number of parameters - Usage: .\File-CheckFileChange.ps1 '<\\Server\Share\Path>' '[strAltCredentials]'"
  exit
}

# Create object
if ( [string]$strAltCredentials -eq ""  )
{
  $exists = Test-Path $strFileName
}
else
{
  $objCredentials = new-object -comobject ActiveXperts.NMServerCredentials
  $objRemoteServer = new-object -comobject ActiveXperts.RemoteServer
  
  $strUsername = $objCredentials.GetLogin($strAltCredentials)
  $strPassword = $objCredentials.GetPassword($strAltCredentials)
  
  if ( $strUsername -eq "" )
  {
    $res = "UNCERTAIN: No alternate credentials defined for [" + $strAltCredentials + "]. In the Manager application, select 'Options' from the 'Tools' menu and select the 'Server Credentials' tab to enter alternate credentials"
    echo $res
    exit
  }
  
  $objRemoteServer.Connect($strAltCredentials,$strUsername,$strPassword)
  
  if ( $objRemoteServer.LastError -ne 0 )
  {
    $res = "UNCERTAIN: Login failed"
    echo $res
    exit
  }        

  $exists = Test-Path $strFileName
}


#################################################################################
# THE SCRIPT ITSELF
#################################################################################


# Checks for the file existance
if ( !($exists) )
{
  $res = "ERROR: File " + $strFileName + " does not exist."
  echo $res
  exit
}  

#Get file name  
$strPlainFile = $strFileName.Split("\")
$strPlainFile = $StrplainFile[$strPlainFile.Count -1]

#set Wscript.Shell object
$objWshShell = new-object -comobject WScript.Shell

#Get new moddate from file
$strModDate = Get-Item $strFileName | select LastWriteTime
$strModDate = $strModDate.LastWriteTime.ToString("MM/dd/yyyy h:mm:ss tt" )

try
{
  #Get cached moddate from registery
  $strPrevModDate = $objWshShell.RegRead("HKLM\Software\ActiveXperts\Network Monitor\Server\VBScript_Cache\" + $strPlainFile)
  $objWshShell.RegWrite("HKLM\Software\ActiveXperts\Network Monitor\Server\VBScript_Cache\" + $strPlainFile, $strModDate, "REG_SZ")
}
catch
{
  $res = "UNCERTAIN: File was not monitored before"
  $objWshShell.RegWrite("HKLM\Software\ActiveXperts\Network Monitor\Server\VBScript_Cache\" + $strPlainFile, $strModDate, "REG_SZ")
  echo $res
  exit
}

if ( $strModDate -ne $strPrevModDate )
{
  $res = "ERROR: File has changed since last check"
  echo $res
  exit
}
else
{
  $res = "SUCCESS: File has not changed since last check"
  echo $res
  exit
}