I have a PowerShell script that reads a register.psd1 file with contents as below.
#{
# Building Zig compiler
zig = #{
name = "zig"
path = ./python/buildzig.py
language = "Python"
os = "all"
}
# Building Windows Terminal for Windows 10.
windowsterminal = #{
name = "WindowsTerminal"
path = ./powershell/msterminal.ps1
language = "Python"
os = "windows"
}
}
I read the file using the following command.
Import-PowerShellDataFile -Path register.psd1
After running the script I get the following error message.
Import-PowerShellDataFile : Cannot generate a PowerShell object for a ScriptBlock evaluating dynamic expressions.
What am I doing wrong and what is the possible solution?
*.psd1 files contain PowerShell hashtable literals and therefore require the same syntax as when defining such literals in code:
Therefore, if you want to create an entry with key path that contains the string literal ./python/buildzig.py (or ./powershell/msterminal.ps1), you must quote it - either form is OK here:
path = '.\powershell\msterminal.ps1'
path = ".\powershell\msterminal.ps1"
However, given that in the context of a *.psd1 file you're virtually limited to literal values, use of '...' (single quotes) makes more sense (see about_Quoting_Rules).
As for what you tried:
A hashtable entry such as path = ./python/buildzig.py attempts to create an entry with key path and the value that is the result of executing file ./python/buildzig.py, because - in the absence of quoting - the token is interpreted as a command (see about_Parsing to learn about how PowerShell parses commands and expressions).
The - unfortunately vague - error message you saw (Cannot generate a PowerShell object for a ScriptBlock evaluating dynamic expressions.), stems from the fact that for security reasons, executing commands isn't permitted in *.psd1 files, which are (mostly[1]) limited to defining literal values.
[1] You can use the following "variables", which in effect are constants: $true, $false, $null. Additionally, depending on the purpose of the *.psd1 file, a select few additional automatic variables are permitted: $PSCulture and $PSUICulture, except in files to be read by Import-PowerShellDataFile, and, additionally, $PSScriptRoot, $PSEdition, and $EnabledExperimentalFeatures in module manifests - see about_Language_Modes.
I have just added ' ' for the path parameters as following after that the error was gone. hope this is the output you wanted.
path = '.\powershell\msterminal.ps1'
Related
I am trying to include a script inside another which is in the same folder, using the dot syntax:
. '.\BaseScript.ps1'
The path to the scripts has a folder with square brackets in the name. Even though I am using relative paths, the path error still occurs.
Moving it to some other path without special characters in the name works fine.
How can such a case be catered while using relative paths?
Unfortunately, PowerShell treats the operands to the . dot-sourcing and & call operators (which includes implicit invocation[1] ) as wildcard expressions, which causes problems with paths that contain [, which is a wildcard metacharacter.
The solution is to escape the [ as `[; e.g., to dot-source a script whose path is ./test[1]/script.ps1:
# Note: '/' and '\' can be used interchangeably in PowerShell.
. ./test`[1]/script.ps1
Important: If the path is relative, it must start with ./ or .\ (see below for full paths).
Note: [ is a wildcard metacharacter, because you can use it to express character ranges ([a-z]) or sets ([56]); while ] is clearly also needed, it is sufficient to escape [.
This unfortunate requirement, which also affects other contexts, is the subject of GitHub issue #4726.
Alternatively - and bizarrely - as Theo's helpful answer shows, the need for this escaping goes away if you use a full path.
# Dot-source 'script.ps1` from the same location as the running
# script ($PSScriptRoot).
# (Use $PWD to refer to the *currrent* dir.)
# Because this results in a *full* path, there is no need to escape, strangely.
. $PSScriptRoot/script.ps1
[1] &, which can invoke any command and runs commands written in PowerShell code in a child scope, isn't strictly needed for invocation; e.g. & ./path/to/script.ps1 and ./path/to/script.ps1 are equivalent; however, & is required if the path is quoted and/or contains variable references - see this answer.
The way around this seems to be using a complete path to the second script:
. (Join-Path -Path $PSScriptRoot -ChildPath 'SecondScript.ps1')
#Theo has a useful workaround, but the cause is that [] must be escaped in paths.
$path = 'C:\path\`[to`]\script.ps1'
I'm trying to use the Build variables in a script. According to this documentation I should be able to use the following:
Write-Host "BUILD_DATE: $Env:BUILD_DATE"
Write-Host "BUILD_REV: $Env:BUILD_REV"
However, I only get the following output
BUILD_DATE:
BUILD_REV:
I've also tried this syntax:
Write-Host "BUILD_DATE: $(Env:BUILD_DATE)"
Write-Host "BUILD_REV: $(Env:BUILD_REV)"
Write-Host "BUILD_DATE: $(Build.Date)"
Write-Host "BUILD_REV: $(Build.Rev)"
But the first segment gives The term 'Env:BUILD_DATE' is not recognized and the second segment gives The term 'Build.Date' is not recognized
How can I use the build variables in my script?
Disclaimer: I know virtually nothing about Azure pipelines, so my answer is based on reading the docs. Do let us know if I got things wrong.
Your first command uses the correct syntax for referencing environment variables in PowerShell (also inside an expandable (double-quoted) string).
(The other commands, based on subexpression operator $(...), mistakenly try to execute commands named Env:BUILD_DAT, ... rather than referencing variables.)
Your problem seems to be that the targeted environment variables do not exist.
The list of predefined variables that are exposed as environment variables does not contain variables named Build.Date / $env:BUILD_DATE and Build.Rev / $env:BUILD_REV.
By contrast, variables named Date and Rev seemingly do exist - as you state, they are used in the default format definition for the Build.BuildNumber / $Env:BUILD_BUILDNUMBER build variable, $(Date:yyyyMMdd)$(Rev:.r) - but are seemingly of a different kind not exposed as env. vars. (unlike Build.BuildNumber / $Env:BUILD_BUILDNUMBER itself, which is exposed).
(I don't know where these variables are defined or how they are classified, and where this is documented - do tell us if you know.)
A quick workaround would be to split the value of $Env:BUILD_BUILDNUMBER into its constituent parts:
# Split the build number into date and revision, by "."
$date, $rev = $Env:BUILD_BUILDNUMBER -split '\.'
"BUILD_DATE: $date"
"BUILD_REV: $rev"
I want to use a variable which is composed of another vsts variable and text, for instance:
vnetname = $vnet_prefix + "vnetid"
However i get an error saying that "A positional parameter cannot be found that accepts argument +.
Anyone advise?
If you mean use the variable in build/release processes, then you can add a variable like this (reference below screenshot):
vnetname = $(vnet_prefix)_vnetid
Then you can use the variable $vnetname or $(vnetname) directly, see Build variables-Format for how to use the variables in different tools.
Alternatively you can pass the value with Logging Commands:
Copy and paste below strings then save as *.ps1 file:
$value = $env:vnet_prefix + "vnetid"
Write-Host "##vso[task.setvariable variable=vnetname]$value"
Check in the PS file
Add a PowerShell task to run the PS file
Use the variable $vnetname in later steps
I am working on a powershell script that will create TFS build definitions. I have used below example as my starting point.
http://geekswithblogs.net/jakob/archive/2010/04/26/creating-a-build-definition-using-the-tfs-2010-api.aspx
I have the script done in powershell and it creates me a build definition file in TFS. One thing I am stuck in is creating Process information such as "Item to build" and "Projects to build". The C# code for this is given below
//Set process parameters
varprocess = WorkflowHelpers.DeserializeProcessParameters(buildDefinition.ProcessParameters);
//Set BuildSettings properties
BuildSettings settings = newBuildSettings();
settings.ProjectsToBuild = newStringList("$/pathToProject/project.sln");
settings.PlatformConfigurations = newPlatformConfigurationList();
settings.PlatformConfigurations.Add(newPlatformConfiguration("Any CPU", "Debug"));
process.Add("BuildSettings", settings);
buildDefinition.ProcessParameters = WorkflowHelpers.SerializeProcessParameters(process);
Below is the powershell code I have written to achive above.
Write-Host"Set process parameters "$now
$process=[Microsoft.TeamFoundation.Build.Workflow.WorkflowHelpers]::DeserializeProcessParameters($def.ProcessParameters)
Write-Host"Set build settings properties "$now
$settings=new-object-`enter code here`TypeNameMicrosoft.TeamFoundation.Build.Workflow.Activities.BuildSettings
$sList=New-Object-TypeNameMicrosoft.TeamFoundation.Build.Workflow.Activities.StringList
$sList="$/pathToProject/project.sln"
$settings.ProjectsToBuild =$sList
$process.Add("BuildSettings", $sList)
But the above segment of code does not create me the Build settings in my build definition file. Myquestion is am I doing this the correct way in powershell? I feel I am not writing the powershell code incorrectly as I am newbie to powershell. Any guidance and
help would be appreciated
Calling a constructor with parameters should be done like this in PowerShell:
$ns = 'Microsoft.TeamFoundation.Build.Workflow.Activities'
$settings.ProjectsToBuild = new-object "$ns.StringList" '$/pathToProject/project.sln'
Also note the use of single quotes around the TF server path. $ is s special character in PowerShell - tells it what follows is either a variable name or sub-expression even in a string. Unless that string is single quoted. In which case, PowerShell doesn't interpret any special characters within the string.
My powershell script takes the following parameter:
Param($BackedUpFilePath)
The value that is getting passed into my script is:
"\123.123.123.123\Backups\Website.7z"
I have another variable which is the location I want to extract the file:
$WebsiteDeploymentFolder = "C:\example"
I am trying to extract the archive with the following command:
`7z x $BackedUpFilePath -o$WebsiteDeploymentFolder -aoa
I keep getting the following error:
Error:
cannot find archive
The following works but I need $BackedUpFilePath to be dynamic:
`7z x '\123.123.123.123\Backups\Website.7z' -o$WebsiteDeploymentFolder -aoa
I think I need to pass $BackedUpFilePath to 7z with quotes but they seem to get stripped out no matter what I try. I am in quote hell.
Thanks.
EDIT: It turns out the problem was I was passing in "'\123.123.123.123\Backups\Website.7z'". (extra single quotes)
The easiest way to work with external command line applications in PowerShell (in my opinion) is to use aliases. For example, the following works fine for me.
Set-Alias Szip C:\Utilities\7zip\7za.exe
$Archive = 'C:\Temp\New Folder\archive.7z'
$Filename = 'C:\Temp\New Folder\file.txt'
SZip a $Archive $Filename
PowerShell takes care of delimiting the parameters correctly.