Powershell script to save only the free diskspace value (in GB) for C:\ in a variable-CodePudding

I need to write a power-shell script, where if the free disk space is more than 50GB, then -"do something", else exit the script - do nothing.

For that I am trying to save the free disk space value in a $var and play with an if-else in my script, something like:

$var = <parse disk space free from Get-PSDrive C output>
if ($var -ge 50) {
        #Do something
}
else {
        #Do nothing
}

I tried this so far:

$var = Get-PSDrive C -psprovider Filesystem | select-object @{Name="Free"; Expression={$_.Free/1GB}}

But printing the $var gives me: @{Free=112.352230072021}, but what I wanted is 112, i.e just the free disk-space value , rounded off to anything before the decimal.

What needs to be done ? is there any Unix style awk or sed to parse outputs in power-shell ?

CodePudding user response：

The Free property on a PSDrive is in Bytes. It's very much straightforward to take the drive(s) where it exceeds a certain number, no need to calculate anything, no need for variables, no need for if/else:

Get-PSDrive C -PSProvider FileSystem | where Free -gt 50GB | foreach {
    Write-Host $_
    # do something
}

50GB is a PowerShell built-in convenience shorthand for 50 * 1073741824. Other such shorthands (KB, MB, TB, PB) exist.

CodePudding user response：

if you REALLY want to use an if/else structure, then this would work. [grin]

the code ...

$TargetDisk = 'c'
$MinDiskFree_GB = 50
# uncomment the line below to show the "too small" error msg
#$MinDiskFree_GB = 5000

$ActualDiskFree_GB = [math]::Round((Get-PSDrive -Name $TargetDisk).Free / 1gb, 2)

if ($ActualDiskFree_GB -gt $MinDiskFree_GB)
    {
    Write-Host ('Drive [ {0} ] has enuff free space. [ {1} GB]' -f $TargetDisk, $ActualDiskFree_GB)
    }
    else
    {
    Write-Warning ('    Drive [ {0} ] does not have enuff free space. [ {1} GB]' -f $TargetDisk, $ActualDiskFree_GB)
    }

output with each of the two test values ...

Drive [ c ] has enuff free space. [ 845.77 GB]
WARNING:     Drive [ c ] does not have enuff free space. [ 845.77 GB]

what it does ...

defines the variables
if you need to run this more than once, it would likely work better as a function with parameters.
gets the free space in GB
compares the actual versus the minimum desired free GB
does the appropriate thing