Test installed PowerShell modules against online versions in the PowerShell Gallery.

Check-ModuleUpdate.ps1

[cmdletbinding()]
[outputtype("moduleInfo")]
Param(
   [Parameter(Position = 0, HelpMessage = "Enter a module name or names. Wildcards are allowed.")]
   [ValidateNotNullorEmpty()]
   [string[]]$Name = "*"
)

Write-Verbose "Getting installed modules"
Try {
   $modules = Get-Module -Name $name -ListAvailable -ErrorAction Stop
}
Catch {
   Throw $_
}

if ($modules) {
   Write-Verbose "Found $($modules.count) matching modules"
   #group to identify modules with multiple versions installed
   Write-Verbose "Grouping modules"
   $g = $modules | Group-Object name -NoElement | Where-Object count -GT 1

   Write-Verbose "Filter to modules from the PSGallery"
   $gallery = $modules.where( { $_.repositorysourcelocation })

   Write-Verbose "Comparing to online versions"
   foreach ($module in $gallery) {

      #find the current version in the gallery
      Try {
         Write-Verbose "Looking online for $($module.name)"
         $online = Find-Module -Name $module.name -Repository PSGallery -ErrorAction Stop
         #compare versions
         if (($online.version -as [version]) -gt ($module.version -as [version])) {
            $UpdateAvailable = $True
         }
         else {
            $UpdateAvailable = $False
         }

         #write a custom object to the pipeline
         [pscustomobject]@{
            PSTypeName       = "moduleInfo"
            Name             = $module.name
            MultipleVersions = ($g.name -contains $module.name)
            InstalledVersion = $module.version
            OnlineVersion    = $online.version
            Update           = $UpdateAvailable
            Path             = $module.modulebase
         }
      }
      Catch {
         Write-Warning "Module $($module.name) was not found in the PSGallery"
      }

   } #foreach
}
else {
   Write-Warning "No matching modules found."
}

Write-Verbose "Check complete"

This code is described at http://jdhitsolutions.com/blog/powershell/5441/check-for-module-updates/

Really useful script. Can be nice to add Param($mods), then add $mods at the end of the $modules = Get-Module -ListAvailable line, to then be able to focus the script on an individual Module or set of Modules as an option.

I had completely forgotten about this script. Posted a revision with better error handling and verbose output.

This script can be installed from the PowerShell Gallery:

Install-Script Check-ModuleUpdate

@jdhitsolutions there's a bug in the version comparison here. Since this is just comparing the raw strings, it doesn't take into account semantic versioning.
For example:

"1.13.0" -gt "1.7.1" == $false

This should evaluate to true, and can be resolved correctly by casting these to System.Version first:

[System.Version]"1.13.0" -gt [System.Version]"1.7.1" == $true

As a side note, it'd also be great to have a flag to only return modules that have updates (eg. something like -Outdated).

You caught me being lazy. Good catch. I've updated the script. And the output includes a boolean property Update that you can use. If the value is True that means it is outdated and that an update is available.

c:\scripts\check-moduleupdate.ps1 | where Update | update-module

The PSScriptTools module has an updated version of this script which you can use as a function. The function properly compares version info.

Hey Jeff, where in the PSScriptTools module is this function? I might be being dense, but I don't see it.

The command in the PSScriptTools module is called Compare-Module.