Description: In Powershell, there are a number of reasons that administrators require the ability to run a script against multiple machines. In many of the cmdlets, there is a -ComputerName parameter that will usually accept a string[] array to run the command against multiple computers.
This post simply covers easy ways I've come across to get computers into a usable format for this parameter. They're posted in no real particular order besides maybe most obvious to least obvious.
1. Import from a basic text file of computer names separated by carriage return/line feeds; e.g.:
[Contents of computers.txt]
server1
server2
server3
[PowerShell command(s)]
Second example uses the alias for the Get-Content cmdlet.
Third example uses .NET.
2. Import from a comma-separated file (CSV) of computer names and other data; e.g.:
[Contents of computers.csv]
Name,OS,IP
server1,w2k3,192.168.2.1
server2,w2k8,192.168.2.2
server3,w2k8,192.168.2.3
[PowerShell command(s)]
3. Get computer names from Active Directory:
[PowerShell command(s)]
4. Manually build a string[] array from computer names on the clipboard:
[PowerShell command(s)]
This post simply covers easy ways I've come across to get computers into a usable format for this parameter. They're posted in no real particular order besides maybe most obvious to least obvious.
1. Import from a basic text file of computer names separated by carriage return/line feeds; e.g.:
[Contents of computers.txt]
server1
server2
server3
[PowerShell command(s)]
First example uses the full cmdlet name.
- PS C:\>Get-Content computers.txt
- PS C:\>gc computers.txt
- PS C:\>[System.IO.File]::ReadAllLines(computers.txt)
Second example uses the alias for the Get-Content cmdlet.
Third example uses .NET.
2. Import from a comma-separated file (CSV) of computer names and other data; e.g.:
[Contents of computers.csv]
Name,OS,IP
server1,w2k3,192.168.2.1
server2,w2k8,192.168.2.2
server3,w2k8,192.168.2.3
[PowerShell command(s)]
- PS C:\>Import-Csv computers.txt | Select-Object -Expand name
Import-Csv essentially reads in a properly formatted CSV file and turns it into a PSCustomObject that has assigns the columns of the CSV to object properties. Because we only need an array of computer names, we Select only the object-property we care about 'name' and use the -ExpandProperty property to create the required string array [string[]].
3. Get computer names from Active Directory:
[PowerShell command(s)]
- PS C:\>Import-Module ActiveDirectory; Get-ADComputer -Filter * | Select-Object -Expand name
- PS C:\>([adsisearcher]'(objectcategory=computer)').FindAll()
First example uses the ActiveDirectory module cmdletsSecond example uses the .NET ADSISearcher class via a type-accelerator ([adsisearcher]) to directly interface with AD via an LDAP search.
4. Manually build a string[] array from computer names on the clipboard:
[PowerShell command(s)]
PS C:\>$computers = ' >>[ctrl-v to paste the contents of the clipboard here] >>' PS C:\>$computers = $computers.Trim().Split()
5. Use some .NET methods:
PS C:\>$computers = [System.IO.File]::ReadAllLines($PathToFile)
...The System.IO.File class has many other methods for reading in data depending on whether you want to use a StreamReader or get the filebytes instead.
