Is it possible to update $local:PSScriptRoot?
In my scripts I am using $local:PSScriptRoot, and I expected it to be updated when Set-Location changes the location.
Set-Location "./subfolder"
$local:PSScriptRoot
expected:
<$local:PSScriptRoot>/subfolder"
Do you know how to update $local:PSScriptRoot or if there is a better practice for this?
$psScriptRoot is not a variable whose value may be changed; it is automatically set at script invocation to the full path of the location of the script file that you are interrogating it from. That is, if the script file you are executing is /usr/local/scripts/pscore/get-data.ps1, the value of $psScriptRoot will be set to /usr/local/scripts/pscore, even if you use Set-Location to set the current working directory to something else, and you will not be able to change it.
As Jeff Zeitlin explained, the automatic variable $PSScriptRoot is automatically set to the location of a script upon invocation of that script.
What you are actually looking for is a different automatic variable: $PWD (PWD stands for "Print Working Directory"), or more specifically its Path property ($PWD.Path). The working directory is what you change with the Set-Location cmdlet.
Related
I'm tasked with writing a powershell script to perform a file download, which will eventually be executed as a scheduled task once a week. I have no background in programming in the windows environment so this has been an interesting day.
I am experiencing a problem with the unexpected handling of the $pwd and $home of the shell.
I pass into my program a download URL and a destination file. I would like the destination file to be a relative path, e.g., download/temp.txt.gz
param($srcUrl, $destFile)
$client = new-object System.Net.WebClient
$client.DownloadFile($srcUrl, $destFile)
Ungzip-File $destFile
Remove-Item $destFile
This actually fails on the call to Remove-Item. If $destFile is a relative path then the script happily downloads the file and puts it in a file relative to $home. Likewise, I then unzip this and my function Ungzip-File makes use of System.IO.Filestream, and it seems to find this file. Then Remove-Item complains that there is no file in the path relative to $pwd.
I am a bit baffled, as these are all part of the shell, so to speak. I'm not clear why these functions would handle the path differently and, more to the point, I'm not sure how to fix this so both relative and absolute paths work. I've tried looking at the io.path methods but since my $home and $pwd are on different drives, I can't even use the IsPathRooted which was seemed so close when I found it.
Any help?
You have to be aware of where you are in the path. $pwd works just fine on the command shell but let's say you have started your script from a scheduled job. You might think $pwd is where your script resides and code accordingly but find out that it actually uses, say %windir%\system32.
In general, I would use fullpath to destination and for paths relative to script folder I would use $PSScriptRoot/folder_name/file_path.
There are catches there too. For example, I noticed $PSScriptRoot will resolve just fine within the script but not within Param() block. I would highly suggest using write-verbose when coding and testing, so you know what it thinks the path is.
[CMDLETBINDING()] ## you need this!
Param()
write-verbose "path is $pwd"
Write-Verbose "removing $destFile"
Remove-Item $destfile
and add -verbose when you are calling your script/function:
myscript.ps1 -verbose
mydownloadfunction -verbose
To use a relative path, you need to specify the current directory with ./
Example: ./download/temp.txt.gz
You can also change your location in the middle of the script with Set-Location (alias: cd)
$PSScriptRoot and $PSCommandPath are very useful in locating script files that are consumed by other scripts. Is there an easy, reliable way of getting the top-level script file that was actually executed? My users are right-clicking .ps1 files to execute them from File Explorer.
Example:
C:\Powershell\a.ps1
C:\Powershell\lib\b.ps1
I need a command that I can use from b.ps1 that preferably returns C:\Powershell\a.ps1, or at least C:\Powershell. $PSScriptRoot, $PSCommandPath, and $MyInvocation.MyCommand.Path all return C:\Powershell\lib\b.ps1, though.
Thanks!
This seems to work:
get-variable psscriptroot -scope ((get-pscallstack).count - 2)
That should get you the scriptroot in the fist child scope of the global scope, which would be the script scope of the initial script invocation.
Inside b.ps1, use the cmdlet:
Get-Location
This will return the parent path that you expect.
Why This Works:
This works because you will navigate to the directory C:\Powershell\ and execute the script a.ps1 from there. When you execute . .\lib\b.ps1 you haven't left that execution location, so it will return exactly what you want.
Note: Note that this only works if you first navigate to the directory first, or for scheduled tasks you specify a "Start in" directory. So if you are in a different directory and execute your first script like this: C:\Powershell\a.ps1 it will return your other directory.
If you are really keen, more info on encapsulation is here: Further Down the Rabbit Hole PowerShell Modules and Encapsulation
I'm writing a powershell cmdlet. From inside of my cmdlet BeginProcessing() method, I want to be able to retrieve the the directory that was the default directory at the time the cmdlet was invoked.
Example:
If the user does this:
cd \myDirectory
invoke-mycmdlet
I want for my code to know that the default shell directory was c:\myDirectory.
When I access Environment.CurrentDirectory, it's always c:\windows\system32
I've seen a similar post on SO where the poster needed to set Environment::Current directory from inside the shell using get-location. That won't work for me.
Basically, my cmdlet does some file system stuff, and I want the user to be able to just cd\ into a directory, and execute my cmdlet, with it operating on the directory that they switched into -- just like you would expect it to work from the old Command Console.
You might want to try this instead, CurrentLocation.Path could also point to other provider paths, such as the registery.
this.SessionState.Path.CurrentFileSystemLocation.Path
You know, I always seem to find it right after I post -- regardless of how long I spent looking before reaching for SO!
So, my cmdlet inherits from PsCmdlet. I found that I could get the path I wanted from
this.SessionState.Path.CurrentLocation.Path
(where "this" is a cmdlet class that inherits from PsCmdlet)
Try the Get-Location cmdlet. It should be the script's current executing location, rather than the powershell host startup folder.
When you use a .NET object from PowerShell, and it takes a filename, it always seems to be relative to C:\Windows\System32.
For example:
[IO.File]::WriteAllText('hello.txt', 'Hello World')
...will write C:\Windows\System32\hello.txt, rather than C:\Current\Directory\hello.txt
Why does PowerShell do this? Can this behaviour be changed? If it can't be changed, how do I work around it?
I've tried Resolve-Path, but that only works with files that already exist, and it's far too verbose to be doing all the time.
You can change .net working dir to powershell working dir: [Environment]::CurrentDirectory = (Get-Location -PSProvider FileSystem).ProviderPath
After this line all .net methods like [io.path]::GetFullPath and [IO.File]::WriteAllText will work without problems
The reasons PowerShell doesn't keep the .NET notion of current working directory in sync with PowerShell's notion of the working dir are:
PowerShell working dirs can be in a provider that isn't even file system
based e.g. HKLM:\Software
A single PowerShell process can have
multiple runspaces. Each runspace can be cd`d into a different file
system location. However the .NET/process "working directory" is
essentially a global for the process and wouldn't work for a
scenario where there can be multiple working dirs (one per runspace).
For convenience, I added the following to my prompt function, so that it runs whenever a command finishes:
# Make .NET's current directory follow PowerShell's
# current directory, if possible.
if ($PWD.Provider.Name -eq 'FileSystem') {
[System.IO.Directory]::SetCurrentDirectory($PWD)
}
This is not necessarily a great idea, because it means that some scripts (that assume that the Win32 working directory tracks the PowerShell working directory) will work on my machine, but not necessarily on others.
When you use filenames in .Net methods, the best practice is to use fully-qualified path names. Or use
$pwd\foo.cer
If you do in powershell console from:
C:\> [Environment]::CurrentDirectory
C:\WINDOWS\system32\WindowsPowerShell\v1.0
you can see what folder .net use.
That's probably because PowerShell is running in System32. When you cd to a directory in PowerShell, it doesn't actually change the working directory of powershell.exe.
See:
PowerTip article on syncing the two directories
Channel9 forum thread
I ran into the same problem a long time ago and now I add the following to the beginning of my profile:
# Setup user environment when running session under alternate credentials and
# logged in as a normal user.
if ((Get-PSProvider FileSystem).Home -eq "")
{
Set-Variable HOME $env:USERPROFILE -Force
$env:HOMEDRIVE = Split-Path $HOME -Qualifier
$env:HOMEPATH = Split-Path $HOME -NoQualifier
(Get-PSProvider FileSystem).Home = $HOME
Set-Location $HOME
}
I have a PowerShell script that does some stuff using the script’s current directory. So when inside that directory, running .\script.ps1 works correctly.
Now I want to call that script from a different directory without changing the referencing directory of the script. So I want to call ..\..\dir\script.ps1 and still want that script to behave as it was called from inside its directory.
How do I do that, or how do I modify a script so it can run from any directory?
Do you mean you want the script's own path so you can reference a file next to the script? Try this:
$scriptpath = $MyInvocation.MyCommand.Path
$dir = Split-Path $scriptpath
Write-host "My directory is $dir"
You can get a lot of info from $MyInvocation and its properties.
If you want to reference a file in the current working directory, you can use Resolve-Path or Get-ChildItem:
$filepath = Resolve-Path "somefile.txt"
EDIT (based on comment from OP):
# temporarily change to the correct folder
Push-Location $dir
# do stuff, call ant, etc
# now back to previous directory
Pop-Location
There's probably other ways of achieving something similar using Invoke-Command as well.
There are answers with big number of votes, but when I read your question, I thought you wanted to know the directory where the script is, not that where the script is running. You can get the information with powershell's auto variables
$PSScriptRoot # the directory where the script exists, not the
# target directory the script is running in
$PSCommandPath # the full path of the script
For example, I have a $profile script that finds a Visual Studio solution file and starts it. I wanted to store the full path, once a solution file is started. But I wanted to save the file where the original script exists. So I used $PsScriptRoot.
If you're calling native apps, you need to worry about [Environment]::CurrentDirectory not about PowerShell's $PWD current directory. For various reasons, PowerShell does not set the process' current working directory when you Set-Location or Push-Location, so you need to make sure you do so if you're running applications (or cmdlets) that expect it to be set.
In a script, you can do this:
$CWD = [Environment]::CurrentDirectory
Push-Location $MyInvocation.MyCommand.Path
[Environment]::CurrentDirectory = $PWD
## Your script code calling a native executable
Pop-Location
# Consider whether you really want to set it back:
# What if another runspace has set it in-between calls?
[Environment]::CurrentDirectory = $CWD
There's no foolproof alternative to this. Many of us put a line in our prompt function to set [Environment]::CurrentDirectory ... but that doesn't help you when you're changing the location within a script.
Two notes about the reason why this is not set by PowerShell automatically:
PowerShell can be multi-threaded. You can have multiple Runspaces (see RunspacePool, and the PSThreadJob module) running simultaneously withinin a single process. Each runspace has it's own $PWD present working directory, but there's only one process, and only one Environment.
Even when you're single-threaded, $PWD isn't always a legal CurrentDirectory (you might CD into the registry provider for instance).
If you want to put it into your prompt (which would only run in the main runspace, single-threaded), you need to use:
[Environment]::CurrentDirectory = Get-Location -PSProvider FileSystem
This would work fine.
Push-Location $PSScriptRoot
Write-Host CurrentDirectory $CurDir
I often used the following code to import a module which sit under the same directory as the running script. It will first get the directory from which powershell is running
$currentPath=Split-Path ((Get-Variable
MyInvocation -Scope
0).Value).MyCommand.Path
import-module "$currentPath\sqlps.ps1"
I made a one-liner out of #JohnL's solution:
$MyInvocation.MyCommand.Path | Split-Path | Push-Location
Well I was looking for solution for this for a while, without any scripts just from CLI. This is how I do it xD:
Navigate to folder from which you want to run script (important thing is that you have tab completions)
..\..\dir
Now surround location with double quotes, and inside them add cd, so we could invoke another instance of powershell.
"cd ..\..\dir"
Add another command to run script separated by ;, with is a command separator in powershell
"cd ..\..\dir\; script.ps1"
Finally Run it with another instance of powershell
start powershell "cd..\..\dir\; script.ps1"
This will open new powershell window, go to ..\..\dir, run script.ps1 and close window.
Note that ";" just separates commands, like you typed them one by one, if first fails second will run and next after, and next after... If you wanna keep new powershell window open you add -noexit in passed command . Note that I first navigate to desired folder so I could use tab completions (you couldn't in double quotes).
start powershell "-noexit cd..\..\dir\; script.ps1"
Use double quotes "" so you could pass directories with spaces in names e.g.,
start powershell "-noexit cd '..\..\my dir'; script.ps1"