PowerShell 技能连载 - Working with [FileInfo] Object

Often, code needs to check on files, and for example test whether the file exists or exceeds a given size. Here is some commonly used code:

$logFile = "$PSScriptRoot\mylog.txt"

$exists = Test-Path -Path $logFile
if ($exists)
{
  $data = Get-Item -Path $logFile
  if ($data.Length -gt 100KB)
  {
    Remove-Item -Path $logFile
  }

}

By immediately converting a string path into a FileInfo object, you can do more with less:

[System.IO.FileInfo]$logFile = "$PSScriptRoot\mylog.txt"
if ($logFile.Exists -and $logFile.Length -gt 0KB) { Remove-Item -Path $logFile }

You can convert any path to a FileInfo object, even if it is not representing a file. That’s what the property “Exists” is for: it tells you whether the file is present or not.

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