How can I get the list of all the default system variables (automatic variables) when you fresh open Powershell or when open a new tab?
ConfirmPreference
ConsoleFileName
DebugPreference
etc.
I am not talking about Get-Variable to receive all the variables, I just want the default ones.
For example an idea like :
[System.Management.Automation.PSVariable]::GetVariable
Just capture all the variables as the first action in your profile. Something like this:
Get-variable * > Autovars.txt
Get-variable * | Export-csv Autovars.csv
That way you'll get the variables that exist before the rest of your profile runs. The second command captures more of the properties of each variable So later on, you could retrieve the data as follows:
type Autovars.txt
Import-csv Autovars.csv | ft
If you mean something different by "more technical", then you'll just have to explain what you are looking for.
Related
I've been making this program where i need to send a command to powershell and in return it gives me the sys UpTime (minutes work better but not mandatory)
As i'm still not used to using powershell, i'm having a lot of problems in getting this intel.
This is what i tryed:
(get-date) - (gcim Win32_OperatingSystem).LastBootUpTime
Gives me the uptime, but i still have no idea how to work with that, so i still need to somehow add something like:
| Select-String -Pattern "TotalMinutes"
But then i need (somehow) to make that powershell gives me that time as return so i can work with it.
maybe to clipboard?
| clip
But if i add all those up, none will work.
Putting in the clipboard is just a way i made to get this info, others might also work.
I'm still very new to this, sorry if i hurt your intellect with stupid questions.
Thanks in advance
By subtracting two [datetime] (System.DateTime) instances, you get a [timespan] (System.TimeSpan) instance, which you can store in a variable:
$timeSpanSinceBoot = (Get-Date) - (Get-CimInstance Win32_OperatingSystem).LastBootUpTime
You can then access its properties as needed, such as .TotalMinutes:
$timeSpanSinceBoot.TotalMinutes
To examine the members of the time-span value's type, use the Get-Member cmdlet:
$timeSpanSinceBoot | Get-Member # lists properties and methods
What is the purpose of this string? I am still new to PowerShell and have seen this come up quiet a bit.
$_.Class
Here is an example of how I have seen it used:
$R.AllElements|?{$_.Class -eq "table"}|select innerText
Does this meant that we are applying a class on the $R variable? Or is there a "Class" already for that variable that we are searching for the string "table"? I have looked around but cannot find any explanation.
Here's an example for you to understand the purpose of $_.xxxxx
$Obj = Get-Item -Path 'C:\Program Files'
This would put any information gathered by the Get-Item command and store it in $Obj. If you then show what's in the variable, it will look something like this
If you would then do $obj.xxx where xxx is one of the property names shown above, it will show you the values under that property like this
Another way to get the values of said properties is how you have shown in your post. If you pipe the variable into a where statement like below, it is especially helpful when trying to filter out some text inside a particular variable. This example is looking for the text prog in the Name property of all the items inside of $Obj2
I wish I had time to give more details, I hope this helps you some! PowerShell is one of the best tools for Automation and Administration in a Windows environment so keep on learnin!
Bonus: Here is a link to documentation on PowerShell's pipelines and how it works, I referred to it as 'pipe' in my wordage above
I have an example code snippet that suggests using
(Get-Process | Where-Object {$_.WorkingSet64 -gt 20mb}).Count
to return the count of all processess using > 20Mb.
It works, but when typing, neither Intellisense or the "Tab" key shows this property, rather they show the properties of an individual process - which I find misleading.
I understand, that specifying an item property will give me the list of that property only, but is there a way to easily see, in general, what ALL the valid propeties are, including list aggregates etc?
Even assigning to a variable
$processes = Get-Process | Where-Object {$_.WorkingSet64 -gt 20mb}
does not show me "Count" as a valid property of $processes until AFTER the assignment has been actually run and the value assigned - when writing the script it still shows the properties for an individual item.
For me, Intellisense / Tab help that does not cover all the options kind of defeats the purpose ... (not having to remember hundreds objects/functions and their properties / parameters).
Is there any way to improve this situation? Some syntax trick have I missed?
The correct way to find out all of the properties of an object is to pipe the output to Get-Member:
Get-Process | Get-Member
Sometimes there are hidden properties and methods that can only be seen if you add the -force switch:
Get-Process | Get-Member -Force
The count property is an automatic property that is always usable on any collection object but that isn't explicitly listed as a property. Another example of an automatic property is length.
Using #() to force an array type is handy when that is what is wanted.
e.g. $processes = #(Get-Process | Where-Object {$_.WorkingSet64 -gt 20mb}). will show you "Count" and the other array properties.
Other than that, let's say the Intellisense has various limitations / shortcomings that I will just have to learn... sigh.
Is there a way to get only the locally declared variables in a powershell script?
In this snippit, I would want it to return only myVar1, myVar2, anotherVar:
$myVar1 = "myVar1"
$myVar2 = "myVar2"
$anotherVar = "anotherVar"
Get-Variable -Scope Script
But it instead returns a ton of other local script variables.
The problem I'm trying to solve, and maybe you can suggest another way, is that I have many Powershell scripts that have a bunch of misc variable constants declared at the top.
I want to export them all to disk (xml) for import later.
So to call Get-Variable bla* | Export-Clixml vars.xml, I need to know all of the variable names.
So is there a way I can like do
$allVars = {
$myVar1 = "alex"
$myVar2 = "iscool"
$anotherVar = "thisisanotherVar"
}
Get-Variable allVars | Export-Clixml "C:\TEMP\AllVars.xml"
And then later Import-Clixml .\AllVars.xml | %{ Set-Variable $_.Name $_.Value } ?
So that the rest of the script could still use $myVar1 etc without major changes to what is already written?
The issue is there are more variables that are accessible in that scope beyond the ones you already declared. One thing you could do is get the list of variables before you declare yours. Get another copy of all the variables and compare the list to just get yours.
$before = Get-Variable -Scope Local
$r = "Stuff"
$after = Get-Variable -Scope Local
# Get the differences
Compare-Object -Reference $current -Difference $more -Property Name -PassThru
The above should spit out names and simple values for your variables. If need be you should be able to easily send that down the pipe to Export-CliXML. If your variables are complicated you might need to change the -depth for more complicated objects.
Caveat: If you are changing some default variable values the above code currently would omit them since it is just looking for new names.
Also not sure if you can import them exactly in the same means as they were exported. This is largely dependent on your data types. For simple variables this would be just fine
I need to know all of the variable names.
The only other way that I am aware of (I never really considered this) would be to change all of the variable to have a prefix like my_ so then you could just have one line for export.
Get-Variable my_* | Export-Clixml vars.xml
How can I enforce powershell to use
Format-Table -auto
as a default formatting when writing a returned array of objects to the console?
Thanks
If you are OK calling the cmdlet every time and if you have at least PowerShell v3.0 then you can set a $PSDefaultParameterValues which you can read more about at about_Parameters_Default_Values.
The syntax that would satisfy your need would be:
$PSDefaultParameterValues=#{"<CmdletName>:<ParameterName>"="<DefaultValue>"}
So we add in the switch by setting it to $true.
$PSDefaultParameterValues = #{"Format-Table:Autosize"=$true}
To remove this you would have to do it much the same as you would a hashtable element
$PSDefaultParameterValues.Remove("Format-Table:Autosize")
From the aforementioned article here is some pertinent information as to how to deal with these.
$PSDefaultParameterValues is a preference variable, so it exists only in the session
in which it is set. It has no default value.
To set $PSDefaultParameterValues, type the variable name and one or more key-value pairs
at the command line.
If you type another $PSDefaultParameterValues command, its value replaces the original
value. The original is not retained.
To save $PSDefaultParameterValues for future sessions, add a $PSDefaultParameterValues
command to your Windows PowerShell profile. For more information, see about_Profiles.
Outside of that I am not sure as it would be difficult to change in a dynamic sense. You would want to be sure that data sent to the stream appears on screen in the same way that format-table -auto does but you would have to make sure that it does not affect data so that you could not capture it or send it down the pipe.
You are looking at creating custom output format files, like Frode F. talks about, then you would need to consider looking at about_Format.ps1xml but you would need to configure this for every object that you would want to display this way.
FileSystem.format.ps1xml, for example, would govern the output from Get-ChildItem. Format-Table is more dynamic and I don't think you can say just use Format-Table in that file.