PowerShell tutorial – Writing to text (log) file in file system – exploring Add-Content and Set-Content CMDLETs

Hi All,

Greetings for the day!!! Today new learning so sharing ! SHARING IS CARING 🙂

Also keen to include as much as PowerShell stuff on Knowledge-Junction – making PowerShell Hub – All PowerShell learning at one place

Details / Background / Use Case

• I am working on my SharePoint online project where I need to write some logs to text file from PowerShell script
• I need to write logs either .log file or .txt file
• We have PowerShell script to perform job
  • Script suppose to read SharePoint list
  • Based on details from SharePoint list, creating a modern communication site
  • And few other properties like – adding owners, hiding site title and so on
• So need to maintain log for every functionality / operation – whether it succeeded or any error occurred
• If there is any error then writing exception in error log file
• Requirement is to maintain log files for success and exceptions for each site and details

We have detailed article on how to create a file (either empty or with initial content) – PowerShell tutorial – Creating text (log) file in file system – exploring New-Item CMDLET

In this article we will discuss how to append content to local file or overwrite the existing content

CMDLETs to write content to file

Set-Content

• Set-Content CMDLET replaces the existing content in a file
• SYNTAX

Set-Content
   [-Path] <string[]>
   [-Value] <Object[]>
   [-PassThru]
   [-Filter <string>]
   [-Include <string[]>]
   [-Exclude <string[]>]
   [-Force]
   [-Credential <pscredential>]
   [-WhatIf]
   [-Confirm]
   [-NoNewline]
   [-Encoding <Encoding>]
   [-AsByteStream]
   [-Stream <string>]
   [<CommonParameters>]

Example :

• Lets add content to knowledjejunction.txt file as

Set-Content c:\temp\knowledgejunction.txt 'Welcome to Knowledge Junction'

• If file is already not created, new file will be created

• Please note, this CMDLET replaces existing content in the file
• So if I run this CMDLET with different / new content it will replace existing content as

Set-Content c:\temp\knowledgejunction.txt 'Welcome again Knowledge Junction. This text will be overwritten in file.'

• Output will be

Welcome again Knowledge Junction

• If we want to append content to file then we need to use “Add-Content” PowerShell CMDLET

Add-Content

Add-Content
   [-Path] <string[]>
   [-Value] <Object[]>
   [-PassThru]
   [-Filter <string>]
   [-Include <string[]>]
   [-Exclude <string[]>]
   [-Force]
   [-Credential <pscredential>]
   [-WhatIf]
   [-Confirm]
   [-NoNewline]
   [-Encoding <Encoding>]
   [-AsByteStream]
   [-Stream <string>]
   [<CommonParameters>]

Add-Content
   [-Value] <Object[]>
   -LiteralPath <string[]>
   [-PassThru]
   [-Filter <string>]
   [-Include <string[]>]
   [-Exclude <string[]>]
   [-Force]
   [-Credential <pscredential>]
   [-WhatIf]
   [-Confirm]
   [-NoNewline]
   [-Encoding <Encoding>]
   [-AsByteStream]
   [-Stream <string>]
   [<CommonParameters>]

• Add-Content CMDLET appends content to specified file
• Examples
  • I am using “Add-Content” PowerShell CMDLET in my script as
  • Maintaining two log files – one for success logs and one for errors
  • Using value attribute for writing content in respective file
    • $owner – UPN of user who will be set as owner of the given site – $siteURL
    • In catch block where we need to log exceptions

try{
      $owner = "sayyam@knowledgejunction1.onmicrosoft.com"
      $siteURL = "https://knowledgejunction1.sharepoint.com/"
      Set-SPOUser -Site $siteURL -IsSiteCollectionAdmin $true -LoginName $owner
      Write-Host "Site collection admin added successfully"
      Add-Content "c:\temp\successlogs.txt" -Value "Site collection admin added successfully - $owner"
   }catch{
    Add-Content "c:\temp\errorlogs.txt" -Value "Site collection admin adding failed - $owner $($_.Exception.Message)"
 }#catch

• If we execute above code, we will get an exception since we are not connecting to our tenant and directly executing the CMDLET – Set-SPOUser
• errorlogs.txt file will be generated as

REFERENCES

• Set-Content
• Add-Content

Thanks for reading !!! HAVE a FANTASTIC LEARNING ! LIFE IS BEAUTIFUL 🙂