Power Shell Get-ChildItem then pipe to Get-Content

Question

I am trying to retrieve the unknown file path of a known filename and then do a Get-Content on that filename so that I can modify it. I know that the file will be in C:\Users\$env:UserName\ but thats as far as I can go (the end user may have it in further in, like Documents or Desktop or somewhere else).

It seems to can do either a Get-ChildItem or a Get-Content but for some reason I can't do both in the same script.

Overall goal: Pipe the results of a Get-ChildItem to the Get-Contents function so that I can modify the file.

Here's my code:

(Get-ChildItem -Path C:\Users\$env:UserName -Filter QA11test.hep) | 
    Foreach-Object {
        $_ # send the current line to output
        if($_ -match "SSL/TLS User Cipher Suites=DEFAULT"){
            "IP Port=2023"
            "Security Option=2"
            $Message = "Your host explorer session has been updated."
            Msg $env:UserName $Message
            exit
        } else {
            $Message = "Script Failed."
            Msg $env:UserName $Message
            exit
        }
    } | Set-Content C:\Users\$env:UserName\Telnet\QA11TestSecure.hep

Need help! Thank you!

Answer 1

There appears to be some confusion with how to go about getting a file, it's contents, and then checking the file contents for some arbitrary line. Rather than write this in a large compound command, I suggest breaking things down into a different style so that pipeline confusion is minimized. There are several ways to accomplish the same task, some are easier to follow than others, especially when debugging.

$fileoutput = @'
IP Port=2023
Security Option=2
'@
$FileToLookAt = Get-ChildItem -Path C:\Users\$env:UserName -Recurse -Filter "QA11test.hep" | Get-Content
if ($FileToLookAt)
{
    $found = ""
    $found = $FileToLookAt | Where-Object {$_ -eq 'SSL/TLS User Cipher Suites=DEFAULT'}
    if ($found)
    {
        $Message = "Your host explorer session has been updated."
        Set-Content -Path C:\Users\$env:UserName\Telnet\QA11TestSecure.hep -Value $fileoutput -Force
    } else 
    {
        $Message = "Script Failed."
    }
} else 
{
    $Message = "QA11test.hep not found."
}
Msg $env:UserName $Message

Edit: OK, there really should be checking on Set-Content to make sure the file/path exists. Assuming it does, something like this should work.

Answer 2

In the simplest case, all you need to do is insert a pipeline segment with a Get-Content command:

Get-ChildItem -Path C:\Users\$env:UserName -Filter QA11test.hep |
  Get-Content | # Send the lines of the input file(s) one by one to ForEach-Object
    ForEach-Object { ...

However, there are problems with your approach:

• If a file is found, the output file is unconditionally written - even if no modifications are made to the contents of the input.

  • Additionally, due to the exit statements in your code, any remaining input lines are omitted from the output file.

• If no file is found, the output file is either created as an empty file (0 bytes) or, if it already existed, replaced with an empty file.

---

Instead, I suggest using an approach based on the switch statement, which is faster, more concise, and more flexible:

Notably, this solution only creates / replaces the output file if an input file was found and modifications were made to it.

Get-ChildItem -Path C:\Users\$env:UserName -Filter QA11test.hep | ForEach-Object {
  $updated = $false
  $newLines = switch -File $_.FullName -Regex { # Loop over all file lines
    'SSL/TLS User Cipher Suites=DEFAULT' { 
       $_, "IP Port=2023", "Security Option=2" # send 2 additional lines
       $updated = $true
    }
    default { $_ } # pass other lines through
  }
  # Rewrite the file only if modifications were made.
  if ($updated) { $newLines | Set-Content C:\Users\$env:UserName\Telnet\QA11TestSecure.hep }
  # Emit the appropriate status message.
  Msg $env:UserName ('Nothing to update.', 'Your host explorer session has been updated.')[$updated]
}

^{Note: If you also need to know whether an input file was found at all - irrespective of whether it needed updating - set $found = $true inside the script block and check it after the command: if (-not $found) { Msg $env:UserName 'QA11test.hep not found' }}

• switch -File $_.FullName -Regex reads the input file line by line, and matches each line against the regex condition:

  • If the regex matches, the original line ($_) is output, along with 2 additional lines; plus, flag $updated is set to indicate that the content was modified.
  • All other lines (the default conditional) are output as-is.

• $newLines = ... captures the (potentially modified) lines in an array.

  • Note that this means that all lines are stored in memory at once, but with text files that is usually not a concern.

• Only if $updated is set is the output file written (Set-Content).

• Finally, the Msg command is invoked with a status-appropriate message.

  • Note the ('msg1', 'msg2')[$updated] expression, which is a shortcut for choosing one of two values based on a flag: if $updated is $true, $true is coerced to array index 1 and therefore selects 'msg2'; if it is $false, the index is 0, and 'msg1' is selected.

Answer 3

Thank you everyone who helped!

(@mklement0, I'm going to modify this to do something close to what your last post does! That helps me a lot.)

I took bits and pieces from different posts and this is what I came up with that does what I need it to do.

This PowerShell script grabs the full path of a known file, "QA11test.hep" and loads it into a variable for later use. It then searches the contents of that file for a specific string "SSL/TLS..etc" and if it finds it, it adds two lines, "Port=2023" and "Security Option 2" below the line it found. Then it takes that new file and adds it to C:\Users\$env:UserName\Desktop\QA11TestSecure.hep without changing the original QA11test.hep file. So instead of piping from get-childitem to get-content, it puts the item retrieved from the get-childitem function into a variable that the get-content function can then search for. Works great!

$FileToLookAt = (Get-ChildItem -Path C:\Users\$env:UserName\ -Recurse -Filter "QA11test.hep") | % { $_.FullName }
$User = $env:UserName
if ($FileToLookAt){
    $updated = $false
    $addtls = Get-Content ($FileToLookAt) | Foreach-Object {
        $_ # send the current line to output
        if($_ -match "SSL/TLS User Cipher Suites=DEFAULT"){
            "IP Port=2023"
            "Security Option=2"
            $updated = $true
        }
    }
    if ($updated) {
        $addtls | Set-Content -Path C:\Users\$env:UserName\Desktop\QA11TestSecure.hep
        $Message = "Host Explorer updated.`nPlease ensure there is a gold LOCK icon at the bottom left `nof the host explorer window.`nIf not, please contact the help center. Thank you."
    } else {
        $message = "File was not updated.`nPlease contant the help center immediatly."
    }
} else {
    $Message = "QA11test.hep not found.`nPlease contact the helpdesk immediately."
}
Msg $env:UserName $Message
exit