So I wanted to know how to make powershell Script A can create powershell Script B
The main goal is to have Script B be independent of Script A (for security purposes). I have Keys that I get with Script A and hash them.
I want to also have Script A create Script B, as Script B will do an action and will also be taken to other separate environments.
So how can I:
A: Make the new script via the first?
B: Have, $hash1 (hash of key1), pass on to Script B, So that when Script B runs in a separate VM or PC environment, it does not require Script A to use $hash1
Thanks
A: Powershell script is saved as text. You (=script A) can print text into file (for example scriptB.ps) and this file can be executed.
B: You can use "return statement" in script A. And if you don't need this hash, so you have to write your code to run even without this input parameter or use default parameter. And how? With if statements probably.
I created a tool that is like what you are describing except that it is more limited in scope, but perhaps more generic. I actually created it not to generate powershell scripts but to generate SQL scripts. I could use it to generate PS scripts, but of a very limited form, which would look like this:
& someFunctionorApp -arg11 -arg12 -arg13 ...
& someFunctionorApp -arg21 -arg22 -arg23 ...
and repeated perhaps a hundred times. The args all come from some data source or other, and I've just plugged generic names in for the sake of example. This generated script might do by brute force something that a clever scripter would do inside a loop, but so be it.
For my tool, the driver is data stored inside a CSV file. I can get CSV files from databases, from spreadsheets, and from simple PS scripts that capture information. Different CSV files have different headers, with different field names, and so on. The tool is generic. The other input to my tool is what I have called a template. A template, in this context, is just a text file with some embedded PS variables. The tool runs through the CSV file picking up actual values to store in place of the PS variables.
The output comes out on the console, but it's easily redirected to a file.
Just for grins, I have included the tool. If the tool is not to your liking, perhaps you can pick up a technique or two and adapt them.
<# This function is a table driven template tool.
It's a refinement of an earlier attempt.
It generates output from a template and
a driver table. The template file contains plain
text and embedded variables. The driver table
(in a csv file) has one column for each variable,
and one row for each expansion to be generated.
5/13/2015
#>
function Expand-csv {
[CmdletBinding()]
Param(
[Parameter(Mandatory=$true)]
[string] $driver,
[Parameter(Mandatory=$true)]
[string] $template
)
Process
{
$OFS = "`r`n"
$list = Import-Csv $driver
[string]$pattern = Get-Content $template
foreach ($item in $list) {
foreach ($key in $item.psobject.properties) {
Set-variable -name $key.name -value $key.value
}
$ExecutionContext.InvokeCommand.ExpandString($pattern)
}
}
}
Related
I want to combine a template that looks like this:
grant $privs
on $table
to $user;
With a CSV file that looks like this:
privs,table,user
ALL,Employees,DBA
READ,Employees,Analyst
"READ, WRITE", Employees, Application
ALL,Departments,DBA
READ,Departments,"Analyst, Application"
To produce an SQL script that looks like this:
grant ALL
on Employees
to DBA;
grant READ
on Employees
to Analyst;
grant READ, WRITE
on Employees
to Application;
grant ALL
on Departments
to DBA;
grant READ
on Departments
to Analyst, Application;
The template has three parameters that look like Powershell variables. The CSV file has enough data
to specify five copies of the template. In real life, it would be more like 200 copies.
I also want to be able to apply the same technique to a variety of CSV files, most of which
do not come from databases. And I want to use a variety of templates, most of which do not
generate SQL. For that reason, I want a technique that deals with plain text files, instead
of attaching to the database.
Note: I am asking this question so as to provide the community with an answer.
I have written a function, Expand-Csv, that does this. Here it is:
<# This function is a table driven template tool.
It generates output from a template and
a driver table. The template file contains plain
text and embedded variables. The driver table
(in a csv file) has one column for each variable,
and one row for each expansion to be generated.
12/12/2016
#>
function Expand-csv {
[CmdletBinding()]
Param(
[Parameter(Mandatory=$true)]
[string] $driver,
[Parameter(Mandatory=$true)]
[string] $template
)
Process
{
$pattern = (Get-Content $template) -join "`n"
Import-Csv $driver | % {
foreach ($p in $_.psobject.properties) {
Set-variable -name $p.name -value $p.value
}
$ExecutionContext.InvokeCommand.ExpandString($pattern)
}
}
}
In the case at hand, the call would look like this:
Expand-Csv grants.csv grants.tmplt > grants.sql
The output that would come to the console gets redirected to a file.
I've tried using this for generating scripts in Powershell itself,
but a word of caution is in order. ExpandString does some of the same processing
that Invoke-Command does, so you can get undesired consequences. I only use it
for the simplest kind of PS code, like a series of calls to some external app.
Let's take the PowerShell statement below as an example:
powershell.exe c:\temp\windowsbroker.ps1 IIS
Is it possible to have it scripted within windowsbroker.ps1 to check for that IIS string, and if it's present to do a specific install script? The broker script would be intended to install different applications depending on what string followed it when it was called.
This may seem like an odd question, but I've been using CloudFormation to spin up application environments and I'm specifying an "ApplicationStack" parameter that will be referenced at the time when the powershell script is run so it knows which script to run to install the correct application during bootup.
What you're trying to do is called argument or parameter handling. In its simplest form PowerShell provides all arguments to a script in the automatic variable $args. That would allow you to check for an argument IIS like this:
if ($args -contains 'iis') {
# do something
}
or like this if you want the check to be case-sensitive (which I wouldn't recommend, since Windows and PowerShell usually aren't):
if ($args -ccontains 'IIS') {
# do something
}
However, since apparently you want to use the argument as a switch to trigger specific behavior of your script, there are better, more sophisticated ways of doing this. You could add a Param() section at the top of your script and check if the parameter was present in the arguments like this (for a list of things to install):
Param(
[Parameter()]
[string[]]$Install
)
$Install | ForEach-Object {
switch ($_) {
'IIS' {
# do something
}
...
}
}
or like this (for a single option):
Param(
[switch]$IIS
)
if ($IIS.IsPresent) {
# do something
}
You'd run the script like this:
powershell "c:\temp\windowsbroker.ps1" -Install "IIS",...
or like this respectively:
powershell "c:\temp\windowsbroker.ps1" -IIS
Usually I'd prefer switches over parameters with array arguments (unless you have a rather extensive list of options), because with the latter you have to worry about spelling of the array elements, whereas with switches you got a built-in spell check.
Using a Param() section will also automatically add a short usage description to your script:
PS C:\temp> Get-Help windowsbroker.ps1
windowsbroker.ps1 [-IIS]
You can further enhance this online help to your script via comment-based help.
Using parameters has a lot of other advantages on top of that (even though they probably aren't of that much use in your scenario). You can do parameter validation, make parameters mandatory, define default values, read values from the pipeline, make parameters depend on other parameters via parameter sets, and so on. See here and here for more information.
Yes, they are called positional parameters. You provide the parameters at the beginning of your script:
Param(
[string]$appToInstall
)
You could then write your script as follows:
switch ($appToInstall){
"IIS" {"Install IIS here"}
}
I've got a wrapper powershell script that I'm hoping to use to automate a few things. It's pretty basic, and accepts a parameter that I want the script to run as if it were a line in the script. I absolutely cannot get it to work.
example:
param( [string[]] $p)
echo $p
# Adds the base cmdlets
Add-PSSnapin VMware.VimAutomation.Core
# Add the following if you want to do things with Update Manager
Add-PSSnapin VMware.VumAutomation
# This script adds some helper functions and sets the appearance. You can pick and choose parts of this file for a fully custom appearance.
. "C:\Program Files (x86)\VMware\Infrastructure\vSphere PowerCLI\Scripts\Initialize-VIToolkitEnvironment.ps1"
$p
In the example above, I want $p to execute as if it were a line in the script. I know this isn't secure, and that's probably where the problem lies.
Here is how I try running the script and passing in a parameter for $p:
D:\ps\test>powershell -command "D:\ps\test\powershell_wrapper.ps1" 'Suspend-VM servername -Verbose -Confirm:$False'
How can I get my parameter of 'Suspend-VM servername -Verbose -Confirm:$False' to run inside my script? If I just include the value in the script instead of pass it in as a parameter it runs without any issues...
You can basically approach this two ways, depending on what your needs really are and how you want to structure your code.
Approach #1 - Invoke-Expression
Invoke-Expression basically allows you to treat a string like an expression and evaluate it. Consider the following trivial example:
Invoke-Expression '{"Hello World"}'
That will evaluate the string as if it were an expression typed in directly, and place the string "Hello World" on the pipeline. You could use that to take your string parameter and run it on-the-fly in your script.
Approach #2 - Using a ScriptBlock
PowerShell has a special data type called a ScriptBlock, where you can bind a script to a variable, and then invoke that script as part of your code. Again, here is a trivial example:
function Test-SB([ScriptBlock]$sb) {
$sb.Invoke()
}
Test-SB -sb {"Hello World"}
This example creates a function with a single parameter $sb that is of type ScriptBlock. Notice the parameter is bound to the actual chunk of code {"Hello World"}? That code is assigned to the $sb parameter, and then a call to the .Invoke method actually executes the code. You could adapt your code to take in a ScriptBlock and invoke it as part of your script.
Approach #3 - Updating your profile
OK, so I said there were two ways to approach it. There is actually a third... sort of... You could add the VMWare cmdlets to your $profile so they are always present and you don't need your wrapper to load in those libraries. Granted, this is a pretty big hammer - but it might make sense if this is the environment you are constantly working in. You could also just create a shortcut to PowerShell that runs a .ps1 on startup that includes those libraries and hangs around (this is what MS did with the SharePoint admin shell and several others). Take a look at this TechNet page to get more info on the $profile and if it can help you out:
http://msdn.microsoft.com/en-us/library/windows/desktop/bb613488.aspx
I've written a powershell script that I run several times a day. It's getting to be somewhat of a chore to execute the script manually (from within Powergui or the shell), so I'd like to create a frontend which prompts me for the variables. I've found that Primalforms can supply me with pre-populated fields that can be adjusted if needed.
My problem is that I would like to create a gui and pass ALL the variables to my external script (this script is already written and will not be part of the Primalforms project).
How would I do this? Or should I pass the variables manually? How would I do that?
(I do not think this would be specific to Primalforms.. I'm rather executing a script with variables with another script as input.)
Any help would be greatly appreciated!
Use splatting. Collect all the values for the parameters in a hashtable (key names match parameter names) and assign each name the value of the parameter from the corresponding text feild in your form. Then pass the hashtable to script B. The following assumes that you have two text fields with names of: filter and path.
## scriptA ##
$params = #{
path=$path.text
filter=$filter.text
}
D:\Scripts\scriptB.ps1 #params
I have a PowerShell script with a number of 'params' at the start:
param(
[switch] $whatif,
[string] $importPath = $(Read-Host "Full path to import tool"),
[string] $siteUrl = $(Read-Host "Enter URL to create or update"),
[int] $importCount = $(Read-Host "Import number")
)
Is there any way I can run this against an answer file to avoid entering the parameter values every time?
I am not getting the reason for the question. All you have to do to call your script is something like:
.\script.ps1 -whatif -importPath import_path -siteUrl google.com -importCount 1
The Read-Host are there as defaults, to be executed ( and then read and assign the values to the parameters ) only if you don't specify the values. As long you have the above comand ( saved in a file so that you can copy and paste into console or run from another script or whatever ), you don't have to enter the values again and again.
Start by setting the function or script up to accept pipeline input.
[CmdletBinding(SupportsShouldProcess=$True,ConfirmImpact='Low')]
param(
[Parameter(Mandatory=$True,ValueFromPipelineByPropertyName=$True)]
[string] $importPath,
[Parameter(Mandatory=$True,ValueFromPipelineByPropertyName=$True)]
[string] $siteUrl,
[Parameter(Mandatory=$True,ValueFromPipelineByPropertyName=$True)]
[int] $importCount
)
Notice that I removed your manually-created -whatif. No need for it - I'll get to it in a second. Also note that Mandatory=$True will make PowerShell prompt for a value if it isn't provided, so I removed your Read-Host.
Given the above, you could create an "answer file" that is a CSV file. Make an importPath column, a siteURL column, and an importCount column in the CSV file:
importPath,siteURL,importCount
"data","data",1
"x","y",2
Then do this:
Import-CSV my-csv-file.csv | ./My-Script
Assuming your script is My-Script.ps1, of course.
Now, to -whatif. Within the body of your script, do this:
if ($pscmdlet.shouldprocess($target)) {
# do whatever your action is here
}
This assumes you're doing something to $target, which might be a path, a computer name, a URL, or whatever. It's the thing you're modifying in your script. Put your modification actions/commands inside that if construct. Doing this, along with the SupportsShouldProcess() declaration at the top of the script, will enable -whatif and -confirm support. You don't need to code those parameters yourself.
What you're building is called an "Advanced Function," or if it's just a script than I guess it'd be an "Advanced Script." Utilizing pipeline input parameters in this fashion is the "PowerShell way of doing things."
To my knowledge, Powershell doesn't have a built-in understanding of answer files. You'll have to pass them in somehow or read them yourself from the answer file.
Wrapper. You could write another script that calls this script with the same parameters you want to use every time. You could also make a wrapper script that reads the values from the answer file, then pass them in.
Optional Parameters. Or you could change the parameters to use defaults that indicate no parameters were passed, then check for a file of a specific name to read values from. If the file isn't found, then prompt for the values.
If the format of the answer file is flexible, (i.e., you're only going to be using it with this Powershell script), you could get much closer to the behavior of an actual answer file by writing it as a Powershell script itself and dot-sourcing it.
if (test-path 'myAnswerfile'){
. 'myAnswerFile'
#process whatever was sourced from the answer file, if necessary
} else {
#prompt for values
}
It still requires removing the Read-Host calls from the parameters of the script.
Following on from Joel you could set up a different parameter set, based around the switch -answerfile.
If that's set the function will look for an answer file and parse though it - as he said you'll need to do that yourself. If it's not set and the others are then the functionis used with the parameters given. Minor benefit I see is that you can still have the parameters mandatory when used that way.
Matt