How do I check if all the files in a folder is read only recursively?

Question

Currently I am getting the the total file number and the file number of read only files and see if they are the same:

function AllReadOnly{
    param([string]$Path)
    $file_count = Get-ChildItem $Path -Recurse -File | Measure-Object | %{$_.Count}
    $read_file_count = Get-ChildItem $Path -Recurse -File -Attributes ReadOnly | Measure-Object | %{$_.Count}
    $read_file_count
    $file_count
}

Even if this is correct it takes a very long time and I can't help but feel like there should be better way to do this.

Answer 1

Currently you're looping twice over all files, so it would already be an improvement if you incremented two variables in the same loop, and then returned a boolean value indicating whether the count is different or not:

function AllReadOnly {
    Param([string]$Path)

    $all = 0
    $ro  = 0
    Get-ChildItem $Path -Recurse -File | ForEach-Object {
      $all++
      if ($_.Attributes.value__ -band 1) { $ro++ }
    }

    $all -eq $ro
}

However, since you want to check if all files are read-only it would suffice to return $false as soon as you encounter the first writable file:

function AllReadOnly {
    Param([string]$Path)

    Get-ChildItem $Path -Recurse -File | ForEach-Object {
      if (-not ($_.Attributes.value__ -band 1)) {
        $false
        continue
      }
    }

    $true
}

---

Edit:

$_.Attributes.value__ is the numeric value of the file's attributes. The binary value 1 indicates that the read-only flag is set, so if a bitwise/logical AND of the attributes value and 1 returns a value != 0 the flag is set, otherwise it's not set. That's because a logical AND returns true/1 only if both operands are true/1 and false/0 otherwise.

Example:

    101001
AND 000001
    ------
    000001 ← flag set

    101000
AND 000001
    ------
    000000 ← flag not set

See Wikipedia for further information about Boolean algebra.