I want to build a PowerShell script for invoking Python3. Now in shell this would be pretty simple but I cannot seem to get the following converted to PS:
../py/python3 myscript.py $#
I am lost somewhere in the maze of Start-Process, get-item, path building, ...
Is there any EASY way of doing that in PowerShell?
PowerShell is a shell, so for the most part, running programs is what it does well. I'm guessing you're converting a Unix shell script which is where $# comes from. The equivalent in PowerShell for that would probably be $args or #args:
../py/python3 myscript.py $args
Within a script, $args contains the arguments to that script. However, within a script block or function it will contain the arguments to that script block or function, so careful when abstracting things in your script.
invoke-expression -command "../py/python3 myscript.py" $#
Related
This is the command that I provided to the customer before:
iex ((New-Object System.Net.WebClient).DownloadString('URL'))
It downloads PS script as a string from URL location and executes the script.
Now I need to pass parameter to this script
iex (((New-Object System.Net.WebClient).DownloadString('URL')) -Parameter 'parameter')
And it is not working because string not accepts parameters
I need to create the simple command (it is important) that will download the script from URL and accept parameters. Otherwise I would save this string to ps1 file and execute it passing the parameter
Could you please help me with that? I am new to PS
Try the following approach:
& ([scriptblock]::Create(
(New-Object System.Net.WebClient).DownloadString('URL')
)) 'Parameter'
Note:
The above runs the script text in a child scope, due to use of &, the call operator, as would happen with local invocation of a script file, whereas Invoke-Expression (iex) runs it in the current scope, i.e. as if it were called with . , the dot-sourcing operator. Change & to . if you want this behavior.
To download the script, you could alternatively use PowerShell's Invoke-RestMethod (irm) cmdlet: Invoke-RestMethod 'URL' or irm 'URL'
[scriptblock]::Create() creates a PowerShell script block, which can then be invoked with & (or .), while also accepting arguments.
As for what you tried:
Invoke-Expression (iex) - which should generally be avoided - has several drawbacks when it comes to executing a script file's content downloaded from the web:
It doesn't support passing arguments, as you've discovered.
An exit statement in the script text would cause the current PowerShell session to exit as a whole.
As noted, the code executes directly in the caller's scope, so that its variables, functions, ... linger in the session after execution (however, it's easy to avoid that with & { iex '...' }).
GitHub issue #5909 discusses enhancing the Invoke-Command cmdlet to robustly support download and execution of scripts directly from the web.
I wrote a script to build all .net projects in a folder.
Issue
The issue is I am getting a missing function error when I call Build-Sollution.
What I tried
I made sure that function was declared before I used it so I am not really sure why it saids that it is not defined.
I am new to powershell but I would think a function calling another functions should work like this?
Thanks in advance!
Please see below for the error message and code.
Error Message
Line |
3 | Build-Sollution $_
| ~~~~~~~~~~~~~~~
The term 'Build-Sollution' is not recognized as the name of a cmdlet, function, script file, or operable program.
Check the spelling of the name, or if a path was included, verify that the path is correct and try again.
Build-Sollution:
Code
param (
#[Parameter(Mandatory=$true)][string]$plugin_path,
[string]$depth = 5
)
$plugin_path = 'path/to/sollutions/'
function Get-Sollutions {
Get-ChildItem -File -Path $plugin_path -Include *.sln -Recurse
}
function Build-Sollution($solution) {
dotnet build $solution.fullname
}
function Build-Sollutions($solutions) {
$solutions | ForEach-Object -Parallel {
Build-Sollution $_
}
}
$solutions_temp = Get-Sollutions
Build-Sollutions $solutions_temp
From PowerShell ForEach-Object Parallel Feature | PowerShell
Script blocks run in a context called a PowerShell runspace. The runspace context contains all of the defined variables, functions and loaded modules.
...
And each runspace must load whatever module is needed and have any variable be explicitly passed in from the calling script.
So in this case, the easiest solution is to define Build-Sollution inside Build-Sollutions
As for this...
I am new to powershell but I would think a function calling another
functions should work like this?
... you cannot use the functions until you load your code into memory. You need to run the code before the functions are available.
If you are in the ISE or VSCode, if the script is not saved, Select All and hit use the key to run. In the ISE use F8 Selected, F5 run all. In VSCode, F8 run selected, crtl+F5 run all. YOu can just click the menu options as well.
If you are doing this from the consolehost, the run the script using dot sourcing.
. .\UncToYourScript.ps1
It's ok to be new, we all started somewhere, but it's vital that you get ramped up first. so, beyond what I address here, be sure to spend time on Youtube and search for Beginning, Intermediate, Advanced PowerShell for videos to consume. There are tons of free training resources all over the web and using the built-in help files would have given you the answer as well.
about_Scripts
SCRIPT SCOPE AND DOT SOURCING Each script runs in its own scope. The
functions, variables, aliases, and drives that are created in the
script exist only in the script scope. You cannot access these items
or their values in the scope in which the script runs.
To run a script in a different scope, you can specify a scope, such as
Global or Local, or you can dot source the script.
The dot sourcing feature lets you run a script in the current scope
instead of in the script scope. When you run a script that is dot
sourced, the commands in the script run as though you had typed them
at the command prompt. The functions, variables, aliases, and drives
that the script creates are created in the scope in which you are
working. After the script runs, you can use the created items and
access their values in your session.
To dot source a script, type a dot (.) and a space before the script
path.
See also:
'powershell .net projects build run scripts'
'powershell build all .net projects in a folder'
Simple build script using Power Shell
Update
As per your comments below:
Sure the script should be saved, using whatever editor you choose.
The ISE does not use PSv7 by design, it uses WPSv5x and earlier.
The editor for PSv7 is VSCode. If you run a function that contains another function, you have explicitly loaded everything in that call, and as such it's available.
However, you are saying, you are using PSv7, so, you need to run your code in the PSv7 consolehost or VSCode, not the ISE.
Windows PowerShell (powershell.exe and powershell_ise.exe) and PowerShell Core (pwsh.exe) are two different environments, with two different executables, designed to run side-by-side on Windows, but you do have to explicitly choose which to use or write your code to branch to a code segment to execute relative to the host you started.
For example, let's say I wanted to run a console command and I am in the ISE, but I need to run that in Pwsh. I use a function like this that I have in a custom module autoloaded via my PowerShell profiles:
# Call code by console executable
Function Start-ConsoleCommand
{
[CmdletBinding(SupportsShouldProcess)]
[Alias('scc')]
Param
(
[string]$ConsoleCommand,
[switch]$PoSHCore
)
If ($PoSHCore)
{Start-Process pwsh -ArgumentList "-NoExit","-Command &{ $ConsoleCommand }" -PassThru -Wait}
Else {Start-Process powershell -ArgumentList "-NoExit","-Command &{ $ConsoleCommand }" -PassThru -Wait}
}
All this code is doing is taking whatever command I send it and if I use the PoSHCore switch...
scc -ConsoleCommand 'SomeCommand' -PoSHCore
... it will shell out to PSCore, run the code, otherwise, it just runs from the ISE>
If you want to use the ISE with PSv7 adn not do the shell out thing, you need to force the ISE to use PSv7 to run code. See:
Using PowerShell Core 6 and 7 in the Windows PowerShell ISE
I can't post all of the script contenet, but the basic idea is that it downloads JSON and converts it to objects using the ConvertFrom-Json cmdlet. Some objects are filtered out, and the rest are written to an XML/XLS document (in the Excel 2003 format). This file is then attached to an email and sent to various people.
The problem I'm having is that it only works when run from the Powershell ISE. Once I try setting up a scheduled task, calling it from cmd, or even calling it from powershell, the attached file is completely empty. It is as if some functions do not run (the one that loops through and creates all rows).
I can continue to run from ISE for the time being, but the idea of this script is to send out an automatic email that will require no intervention. Any ideas as to what could be causing this?
You need to run the script "dot sourced"
which can be done like this
powershell.exe -noexit -file c:\test.ps1
or
pwershell.exe -noexit ". c:\test.ps1"
See this link under the -File section
http://technet.microsoft.com/en-us/library/hh847736.aspx
Based on the answer from the comments to the original post, it seems that the script was (unexpectedly?) working in the ISE because of the bug/quirk/feature that allows scripts run in the ISE to be aware of variables used in the console window and vice-versa.
This can often cause logic problems or unexpected results when a script runs with a variable already defined (and not initialized carefully in the script).
Ways to avoid this problem:
Try to test your code in as clean an environment as possible.
http://powershell.com/cs/blogs/tips/archive/2015/02/12/getting-a-clean-powershell-environment.aspx
To make sure a script runs in a completely clean test environment, you
could of course restart the PowerShell ISE. A more convenient way is
to open another PowerShell tab: in the PowerShell ISE, choose File/New
PowerShell Tab.
Use Set-StrictMode 2 in your script to catch undefined variables, etc.
https://technet.microsoft.com/en-us/library/hh849692.aspx
Set-StrictMode -Version 2.0
Prohibits references to uninitialized variables (including uninitialized variables in strings).
Prohibits references to non-existent properties of an object.
Prohibits function calls that use the syntax for calling methods.
Prohibits a variable without a name (${}).
I have had this problem be for and for me executing the scrip using single-threaded function from powershell worked.
You could also try some other options, go to this link to find more info.
Example
powershell.exe -noexit c:\test.ps1 -sta
Change the missing variable or function to global.
function global:mycall{}
Start your Script with:
[cmdletbinding()]
In a powershell script I need to start the process powershell and tell it to run the script foo.ps1 like so:
start-process powershell C:\foodir\foo.ps1
But I ran into problems when I needed the script foo to be run with parameters. I tried some code like this:
start-process powershell (C:\foodir\foo.ps1 -paramforfoo test)
but this simply freezes the script when it gets to this line and throws no errors. I think it is trying to pass the parameter test to the powershell process and not to the script foo. How can I run this script with parameters?
Try using quotes to collect your command. E.g.
Start-Process powershell ".\Untitled3.ps1 -testparam 'hello world'"
Does anyone know how to execute a PowerShell script from SSIS? I have created the script and it works from from the command line. The script takes a couple of command line parameters, which work fine when called from cmd.exe.
I'm using an Execute Process Task in SSIS and cannot get the script file to execute. I'm using expressions to pass in the name of the script and the command line arguments. The task is returning an incomplete string token error.
From VS to launch PSH with an extra script (for a Cmdlet project) I use the following commandline:
powershell -noexit -command ". ./Startup.ps1"
The -noexit will keep the instance around (so you wouldn't want that), putting all the real commands in a script to be dot-sourced avoids a really long command line.
Go to Execute Process Task Editor -> Process tab and set the following options:
Executable - C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
Arguments - -File ".\PowershellScript/ps1" "arg_1_value" "arg_2_value" ... "arg_n_value"
Refer to the below screenshot: