Auto Update for PowerShell scripts
This script will check the remote repository to se if there’s a new version of he current script file, if so, it will update it and re-run it.
Initializaton, get the git exe path and the current script path
$GitCmd = (Get-Command "git.exe")
if($Null -eq $GitCmd){ throw "git.exe not found" }
$GitExe = $GitCmd.Source
$ScriptPath = "$PSCommandPath"
Get the branches names for the local and the remote branch…
$RemoteBranch = & "$GitExe" 'for-each-ref' '--format=%(upstream:short)' "`"$(git symbolic-ref -q HEAD)`""
$LocalBranch = & "$GitExe" 'branch' '--show-current'
Get the current number of new revisions available, 0 if we are up to date
[uint32]$NewVers = & "$GitExe" 'diff' "$RemoteBranch..$LocalBranch" "$ScriptPath" | Measure-Object -Line | Select -ExpandProperty Lines
How to test
- Clone the repo at 2 different locations
- Update the AutoUpdate.ps1 script in one location (location 1) and
commit/push - Go to location #2, and run
. .\AutoUpdate.ps1
You will get this:
> . .\AutoUpdate.ps1
This script was updated and will restart.
Hello World
Check for New Version
This Test-NewScriptVersion function will get the local and remote branches names and use them to diff the local script ( $PSCommandPath ) with the version in the repo. If there is a difference, we know we need to update.
function Test-NewScriptVersion{
[CmdletBinding(SupportsShouldProcess)]
param()
begin{
try{
$GitCmd = (Get-Command "git.exe")
if($Null -eq $GitCmd){ throw "git.exe not found" }
$GitExe = $GitCmd.Source
$ScriptPath = "$PSCommandPath"
if(-not(Test-Path -Path "$ScriptPath")){ throw "file not found" }
}catch{
write-error "$_"
}
}
process{
try{
$RemoteBranch = & "$GitExe" 'for-each-ref' '--format=%(upstream:short)' "`"$(git symbolic-ref -q HEAD)`""
$LocalBranch = & "$GitExe" 'branch' '--show-current'
Write-Verbose "Remote Branch: `"$RemoteBranch`""
Write-Verbose "Local Branch: `"$LocalBranch`""
$Output = & "$GitExe" 'fetch' *> "$ENV:Temp\gitout.txt" | Out-Null
$HeadRev = & "$GitExe" 'log' '-n' '1' '--no-decorate' '--pretty=format:%H' "$ScriptPath"
$Ret = $False
[uint32]$NewVers = & "$GitExe" 'diff' "$RemoteBranch..$LocalBranch" "$ScriptPath" | Measure-Object -Line | Select -ExpandProperty Lines
if($NewVers -gt 0){
Write-Verbose "A new version is available for `"$ScriptPath`""
Write-Verbose "Head Rev: `"$HeadRev`""
$Ret = $True
}else{
Write-Verbose "No updates for `"$ScriptPath`""
Write-Verbose "Head Rev: `"$HeadRev`""
}
$Ret
}catch{
write-error "$_"
}
}
}
Update the Script
Simple Git Pull
function Update-ScriptVersion{
[CmdletBinding(SupportsShouldProcess)]
param()
begin{
try{
$GitCmd = (Get-Command "git.exe")
if($Null -eq $GitCmd){ throw "git.exe not found" }
$GitExe = $GitCmd.Source
$ScriptPath = "$PSCommandPath"
if(-not(Test-Path -Path "$ScriptPath")){ throw "file not found" }
$DirName = (Get-Item -PAth "$ScriptPath").DirectoryName
}catch{
write-error "$_"
}
}
process{
try{
pushd "$DirName"
$Output = & "$GitExe" 'pull' > "$ENV:Temp\gitout.txt" | Out-Null
popd
}catch{
write-error "$_"
}
}
}
Restart the Current Script
After we see we need to update and that the update was done, we restart the current script
$NewVersionAvailable = Test-NewScriptVersion
if($NewVersionAvailable){
Update-ScriptVersion
Write-Host "This script was updated and will restart."
Start-Sleep 1
. "$ScriptPath"
# Start-Process pwsh.exe -ArgumentList ("-NoProfile -ExecutionPolicy Bypass -File `"{0}`"" -f $PSCommandPath)
Exit
}
# To test, change the color...
Write-Host "The script logic starts here..." -f Red
Get the code
Important Note Do You have Issues accessing the core repository? Don’t be shy and send me an EMAIL to guillaumeplante.qc@gmail.com and I will fix access for you
