Cannot get file last modified time via PowerShell script - windows

Question

What I tried to do is searching a directory to output file path, name, version and last modified time into a txt file.
My code as below:
function Get-Version($filePath)
{
$name = #{Name="Name";Expression= {split-path -leaf $_.FileName}}
$path = #{Name="Path";Expression= {split-path $_.FileName}}
$time = #{Name="Last Modified"; Expression={Get-Date $_.LastWriteTime}}
dir -recurse -path $filePath | % { if ($_.Name -match "(.*exe)$") {$_.VersionInfo} } | select $path, $name,$time, FileVersion
}
Get-Version('E:\PS test') >> "version_info.txt"
However the output txt has name, path and version, but no last modified time.
Any hints?
Thanks!

Answer 1

It's because you're returning the .VersionInfo property from your ForEach-Object (%) call, and .LastWriteTime is a property of the file object, not the version info. Have a look at this:
function Get-Version($filePath)
{
$name = #{Name="Name";Expression= {split-path -leaf $_.VersionInfo.FileName}}
$path = #{Name="Path";Expression= {split-path $_.VersionInfo.FileName}}
$time = #{Name="Last Modified"; Expression={Get-Date $_.LastWriteTime}}
$version = #{Name="FileVersion"; Expression={$_.VersionInfo.FileVersion}}
dir -recurse -path $filePath | ? { $_.Name -match "(.*exe)$" } | select $path, $name,$time, $version
}
By Changing the defintiion of $name and $path to refer directly to the version info, you can operate on the original object. I also had $version to get at the FileVersion you were referring to in the select.
That makes the ForEach-Object redundant, since you'd only be passing along the input. Since you were only checking a condition in it anyway, easier to convert it to Where-Object (?).
Expanding your aliases makes it look like this:
function Get-Version($filePath)
{
$name = #{Name="Name";Expression= {Split-Path -Leaf $_.VersionInfo.FileName}}
$path = #{Name="Path";Expression= {Split-Path $_.VersionInfo.FileName}}
$time = #{Name="Last Modified"; Expression={Get-Date $_.LastWriteTime}}
$version = #{Name="FileVersion"; Expression={$_.VersionInfo.FileVersion}}
Get-ChildItem -Recurse -Path $filePath | Where-Object { $_.Name -match "(.*exe)$" } | Select-Object $path, $name,$time, $version
}
However I should also point out that you can filter the file names directly in dir (Get-ChildItem), making the Where-Object superfluous too:
function Get-Version($filePath)
{
$name = #{Name="Name";Expression= {Split-Path -Leaf $_.VersionInfo.FileName}}
$path = #{Name="Path";Expression= {Split-Path $_.VersionInfo.FileName}}
$time = #{Name="Last Modified"; Expression={Get-Date $_.LastWriteTime}}
$version = #{Name="FileVersion"; Expression={$_.VersionInfo.FileVersion}}
Get-ChildItem -Recurse -Path $filePath -Filter *.exe | Select-Object $path, $name,$time, $version
}
And then based on your comment, I realized it can be simplified even more:
function Get-Version($filePath)
{
$path = #{Name="Path";Expression= {$_.DirectoryName}}
$time = #{Name="Last Modified"; Expression={$_.LastWriteTime}}
$version = #{Name="FileVersion"; Expression={$_.VersionInfo.FileVersion}}
Get-ChildItem -Recurse -Path $filePath -Filter *.exe | Select-Object $path, Name,$time, $version
}
$name is not needed because the file object already has a property called .Name that has the file name.
$path can be simplified because $_.DirectoryName already has the path.
$time can be simplified because the .LastWriteTime property is already a [DateTime] so you don't need Get-Date.
The only reason you still need the name/expression hashes for those is to have the fields be named something other than the underlying property. If you don't care about that, you could do this:
function Get-Version($filePath)
{
$version = #{Name="FileVersion"; Expression={$_.VersionInfo.FileVersion}}
Get-ChildItem -Recurse -Path $filePath -Filter *.exe | Select-Object DirectoryName, Name, LastWriteTime, $version
}