Pull and rebase updates for all Git repositories in a base directory. This can optionally be scheduled to run via a cron job or Windows Task Scheduler.

Update-GitRepositories.ps1

function Update-GitRepositories {

  <#
  .SYNOPSIS
    Pulls updates for Git repositories.

  .DESCRIPTION
    This function invokes `git pull --rebase` on all Git repositories found in the specified base directory.

  .PARAMETER BaseDirectory
    The base directory where Git repositories are located. The function will search for directories containing a `.git` subdirectory.
    
    Mandatory : true
    Type      : string
    Position  : named
  
  .PARAMETER Rebase
    Pull with rebase.
    
    Mandatory : false
    Type      : switch
    Position  : named

  .EXAMPLE
    # Pull updates for all Git repositories in the default base directory
    Update-GitRepositories -BaseDirectory ~/GitHub/
  
  .EXAMPLE
    # Pull and rebase updates for all Git repositories in the default base directory
    Update-GitRepositories -Rebase -BaseDirectory ~/GitHub/

  .NOTES
    Requirements:
      - Operating System(s):
        - Windows
        - Linux
        - macOS
      - Packages:
        - "git"

    This can be scheduled using cron on *nix systems or Task Scheduler on Windows systems.
  #>

  [CmdletBinding()]
  param (
    [Parameter(Mandatory = $true)]
    [ValidateNotNullOrEmpty()]
    [string]$BaseDirectory,
    [Parameter(Mandatory = $false)]
    [switch]$Rebase
  )
  
  begin {
    $repositories = Get-ChildItem -Path $BaseDirectory.Trim() -Directory | Where-Object { Test-Path "$($_.FullName)\.git" }
  }
  
  process {

    foreach ($repository in $repositories) {
      Set-Location -Path "$($repository.FullName)"
      if ($Rebase) {
        Write-Information "Pulling with rebase: $($repository.FullName)" -InformationAction Continue
        git pull --rebase
      } else {
        Write-Information "Pulling without rebase: $($repository.FullName)" -InformationAction Continue
        git pull
      }
      
    }

  }

  end {
    Set-Location -Path ~
  }

}

# Optional: Uncomment the line below to run the function immediately.
# This was functionalized for portability and reuseability.
# Update-GitRepositories -Rebase -BaseDirectory ~/GitHub/