How to read powershell table from file

Question

I have this content in a file:

File Versions              
---- --------              
aaa  {1.0.0.123, 1.0.0.124}
bbb  {1.0.0.123, 1.0.0.124}

How to read it in powershell into table, or typed array?

I've created the file by this script:

$versions = $dictionary | ForEach-Object{
   $properties = @{
      File =  $dictionary.Key
      Versions = $dictionary.Value <# an array of strings #> 
   }
   New-Object PSObject -Property $properties
}

$versions | Out-File "filesVersions.txt"

The script is not used anymore. It's just for demostration of what is in the filesVersions.txt file.

What I actually want is to store a key value pairs in a file, where key is FileName and Value is list of versions.

From time to time I need to read the file content, all a new row or a new version to existing row and save it back.

I wanted to use Format-Table output for it.

That looks like you saved Format-Table output to a file. Do you have control over that output. It would be easier to address that problem then to parse it back now. Or is it actually a CSV file and you could just use Import-CSV "filesVersions.csv". Or is this a large file and that is why you use ReadAllLines? — Matt
See my edit with a little more explanation. It does not matter what is filesVersions.csv or $dictionary since it does not exist anymore. It's just my test data, which I saved to a file and I want to read it back. — Liero
@Liero You can't (reliably) do that - how would you determine whether {1.0.0.123, 1.0.0.124} represents an array (of what? could be versions, IP addresses) or just the string literal "{1.0.0.123, 1.0.0.124}"? As @Matt said, exporting to another format in the first place is how you'd solve this problem in the real world (eg. Export-CliXml or Export-Csv instead of formatted output to Out-File). — Mathias R. Jessen

Matt Matt · Accepted Answer · 2016-02-01T14:57:16

I wanted to use Format-Table output for it. Sorry but that is not the way you should be doing it. You are adding a lot of unnecessary overhead. You are looking at string parsing which can be unreliable and tedious.

PowerShell's power comes from objects. Using Export-CSV would be ideal in this situation. However you would need to do something with that array going both directions.

$versions = $dictionary | ForEach-Object{
   $properties = @{
      File =  $dictionary.Key
      Versions = $dictionary.Value -join "|"
   }
   New-Object PSObject -Property $properties
}

$versions | Export-Csv "filesVersions.csv" -NoTypeInformation

When you go to import the data back into PowerShell to get the objects you would need to split that field to get the array back.

Import-Csv "filesVersions.csv" | ForEach-Object{
    # Update the property
    $_.Versions = $_.Versions -split "|"
    # Send the updated object down the pipe
    $_
}

Or using a calculated property

Import-Csv "filesVersions.csv" | Select-Object File,@{Name="Versions";Expression={$_.Versions -split "|"}}

Like Mathias says you could also use Export-CLIXML and you would not need to do the join or anything. I personally think that is for more complex output then what you are doing here.

How to read powershell table from file

2 Answers

`ConvertFrom-SourceTable`