Retrieve integers from a text file using PowerShell

Question

I would like to retrieve some numbers from a text file using Windows PowerShell. Assume that I have a text file values.txt that looks like this (I can modify it as I want):

foo=100
bar=-3
foobar=-15
asdf=-4

I would like to add a variable to my PowerShell script called $bar that is equal to the number -3, as the text file says it should be. How do I do this?

Answer 1

^{Note: The input file looks like part of an *.ini file; for more full-featured support of such files, consider a third-party module such as PSIni.}

As Matt suggests in a comment on the question, ConvertFrom-StringData sounds like the right tool:

# Read the key-value pairs stored in file file.txt into [hashtable] $ht
PS> ($ht = Get-Content -Raw -LiteralPath file.txt | ConvertFrom-StringData)

Name                           Value                                                                                                                                               
----                           -----                                                                                                                                               
foo                            100                                                                                                                                                 
bar                            -3                                                                                                                                                  
foobar                         -15                                                                                                                                                 
asdf                           -4                                                                                                                                                  

# Access a specific value:
PS> $ht.foo  # or: $ht['foo']
100

Note:

• ConvertFrom-StringData returns a hashtable rather than creating individual variables:

  • As shown above, you must access the foo input line's value as $ht.foo (or $ht['foo']) rather than $foo, for instance.

  • To ensure that only a single hashtable is created, Get-Content -Raw (PSv3+) must be used to pass the entire input file as a single string.

• ConvertFrom-StringData only ever creates [string] values, so if the input values should be treated as numbers, for instance, manual conversion is required:

  # .Clone() is needed to support enumeration and modification in the same loop.
  foreach($key in $ht.Keys.Clone()) { $ht.$key = [int] $ht.$key }
  

• Generally, there are more subtleties to consider, such as \ rather than ` serving as the escape character and quotes getting retained as literals - see the docs.

Answer 2

This should work:

$file = "C:\test.txt"

foreach($line in (Get-Content $file)) {
    $a = $line.Split("=")
    New-Variable -Name $a[0] -Value $a[1]
}

Write-Output ""
Write-Output "Variable Check ::"

Write-Output "foo = $foo"
Write-Output "bar = $bar"
Write-Output "foobar = $foobar"
Write-Output "asdf = $asdf"

You can also put the name/value in different variables if you don't want to use an array, just change the for loop:

$a,$b = $line.Split("=")
New-Variable -Name $a -Value $b

Using Matts suggestion of ConvertFrom-StringData :

$line =  $line | ConvertFrom-StringData
New-Variable -name $line.Keys -Value $line.Values

hope this helps