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
Related
Problem
I want to know if there is a easy way to search multiple objects in a WMI object or CIM instance.
I'm aware it's possible with commands like
Get-CimInstance Win32_BaseBoard | Select-Object Manufacturer,Product
But I want a command with a dot notation where you can set multiple objects for a search like (Get-CimInstance Win32_BaseBoard).Manufacturer with more than one object.
Something like (Get-CimInstance Win32_BaseBoard).Object1.Obejct2.Object3
Ben's solution from the comments will work but note that it calls Get-CimInstance once for each property you want, even though that's unnecessary (could take a while depending on the call you're making).
Let's look at it a few other ways. We'll start by storing the wanted property names in an array.
$properties = 'Manufacturer', 'Product'
Now we can do something similar to what Ben did:
$allValues = $properties |
ForEach-Object -Begin {
$bb = Get-CimInstance Win32_Baseboard
} -Process {
$bb.$_
}
That keeps his approach but does the CIM call once.
If you want to do with dot notation purely, you can use the .ForEach() method and the .PSObject hidden property to get at the properties:
(Get-CimInstance Win32Baseboard).ForEach({$_.PSObject.Properties.Where({$_.Name -in $properties}).Value})
As noted, DotNotation (Intellisense) is 1:1 / single node / collection thing. You can validate this, by pushing the result of the call to XML and walking the nodes.
(Get-CimInstance Win32_BaseBoard | ConvertTo-Xml).Objects.Object.Property
(Get-CimInstance Win32_BaseBoard | ConvertTo-Xml).Objects.Object.Property.name
(Get-CimInstance Win32_BaseBoard | ConvertTo-Xml).Objects.Object.Property.'#text'
The only other option off the top of my head is constructing a proxy that uses enums and switches for all possible properties for the namespace you are using.
That's way more unneeded effort and code to just do what BenH has pointed out, specifically because you'd have to do that for every class.
Now, if you just wanted to shorthand this, maybe do this
$Base = Get-CimInstance Win32_BaseBoard
$Base.Manufacturer;$base.Model;$base.Name;$Base.PartNumber
But that is just unwieldy, especially, since all this really doing is single commands set on a single line with the command break separator, the semi-colon. Which is a wrong thing to do. IMHO.
---small rant ---
If you need the separator, then just put the next thing on a new line and avoid the semi-colon. I mean, I can see that semi-colon use as the PoSH console host, but in a real script, function, module, well, just, no. Again, IMHO
--- small rant ---
Lastly, depending on what your target PoSH version is, DotNotation had issues in v2 - v3 days
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.
I'm having a problem getting Powershell to behave the way I'm expecting.
I'm trying to use get-wmiobject win32_networkconnection to list the mapped drives for the current user, so I can loop through the drives.
When I run $var = get-wmiobject win32_networkconnection | select -expand localname I get exactly what I expect: a list of the drive letters for the mapped network connections.
However, when I run $var = (get-wmiobject win32_networkconnection).localname I get nothing. It doesn't seem to be selecting the property correctly.
This is problematic, because, ideally, I'd like to loop over all the drives, and then select the various properties for each drive. Instead, it seems like I'll be forced to kludge together an iterator, and then iterate over all the variables one at a time (not very elegant, in my opinion).
I'm not super experienced with Powershell, so there may be something I'm missing. However, from what I've read, this should be working. Is this a limitation of get-wmiobject?
What you're trying to do only works in PowerShell 3.0 and newer versions. The official documentation is very vague:
What's New in Windows PowerShell 3.0
Windows PowerShell Language Enhancements
Windows PowerShell 3.0
includes many features [...] The improvements include
property enumeration, count and length properties on scalar objects,
new redirection operators [...]
This blog post goes a bit more into depth: New V3 Language Features
Yes, this is a limitation of PowerShell 2.0.
Your call to Get-WmiObject is returning an array. In PS2, you would need to pipe the array into something like Select-Object or otherwise iterate over it and reference each individual item.
In PS3+, you can use $array.PropertyName and it does that for you, returning an array of properties.
intead of select propertyName, you can use select -exp propertyName
In PoweShell 2 we did:
Get-ChildItem | ForEach-Object {$_.LastWriteTime} | Sort-Object
In Powershell 3 we do:
(Get-ChildItem).LastWriteTime | Sort-Object
But how does it work, i read this blog post on MSDN and they say that its faster because the foreach loop isnt running? So how does it enumerate the properties then ?
PowerShell is doing the hard work for us and it loops over the collection internally. I like to call this "implicit foreach". Assuming the member you specified is present on each object, if the member you specified is a property, you get back its value. If it's a method, it invokes the method on the each object.
In v2, to get all process names you had to take care of looping yourself:
Get-Process | Foreach-Object {$_.Name}
In v3, the equivalent would be:
(Get-Process).Name
Same applies to methods. To kill all processes with name starting with note*:
(Get-Process note*).Kill()
The blog says foreach-object cmdlet is not running. Now it is taken care of by the language engine and not a cmdlet, making it faster. How it EXACTLY works is internal implementation detail and I think that is not what you really want to know.
I found a powershell tip regarding $profile.psextended that returns all of the various Powershell profiles and their locations. Having never see that before I ran ($profile | get-member). psextended was not in the list of results.
Having access to some very helpful MVPs on another site I asked how the psextended property was found. Within minutes I got a reply that using ($profile | gm -View all) should do the trick. I tried this and still had no results matching what I was looking for. If you enter $profile. and keep hitting the tab button it scrolls through the possible matches. psextended is nowhere to be found. Am I losing my mind or just plain blind?
Any help would be appreciated as I do not want to frustrate or annoy the guy trying to help me.
Thanks.
--
Eric
Every object, once assigned to a variable, is wrapped in a special semi-transparent object called a PSObject. This is powershell's way of trying to level the playing field for the different types of things that be assigned to a variable. There are four "special" properties exposing different things for any given variable in powershell:
ps> $o = 1
ps> $o.psobject
...
ps> $o.psadapted
...
ps> $o.psextended
...
ps> $o.psbase
...
You can read about these properties over on:
Link
Sorry. This was answered by Shay Levy (http://blogs.microsoft.co.il/blogs/ScriptFanatic/) on another service. Posted here to close the topic.
$profile | get-member -Force
lists the result I was looking for and several more for me to check out.