A better way to check if a path exists or not in PowerShell

Question

I just don t like the syntax of   if  Test-Path  path            and   if  -not  Test-Path  path           if    Test-Path  path             especially there is too many parenthesis and not very readable when checking for  not exist  for such a common use  What is a better way to do this   Update  My current solution is to use aliases for exist and not-exist as explained here      Related issue in PowerShell repository  https   github com PowerShell PowerShell issues 1970

User · Accepted Answer

If you just want an alternative to the cmdlet syntax, specifically for files, use the File.Exists() .NET method:

if(![System.IO.File]::Exists($path)){
    # file with path $path doesn't exist
}

If, on the other hand, you want a general purpose negated alias for Test-Path, here is how you should do it:

# Gather command meta data from the original Cmdlet (in this case, Test-Path)
$TestPathCmd = Get-Command Test-Path
$TestPathCmdMetaData = New-Object System.Management.Automation.CommandMetadata $TestPathCmd

# Use the static ProxyCommand.GetParamBlock method to copy 
# Test-Path's param block and CmdletBinding attribute
$Binding = [System.Management.Automation.ProxyCommand]::GetCmdletBindingAttribute($TestPathCmdMetaData)
$Params  = [System.Management.Automation.ProxyCommand]::GetParamBlock($TestPathCmdMetaData)

# Create wrapper for the command that proxies the parameters to Test-Path 
# using @PSBoundParameters, and negates any output with -not
$WrappedCommand = { 
    try { -not (Test-Path @PSBoundParameters) } catch { throw $_ }
}

# define your new function using the details above
$Function:notexists = '{0}param({1}) {2}' -f $Binding,$Params,$WrappedCommand

notexists will now behave exactly like Test-Path, but always return the opposite result:

PS C:\> Test-Path -Path "C:\Windows"
True
PS C:\> notexists -Path "C:\Windows"
False
PS C:\> notexists "C:\Windows" # positional parameter binding exactly like Test-Path
False

As you've already shown yourself, the opposite is quite easy, just alias exists to Test-Path:

PS C:\> New-Alias exists Test-Path
PS C:\> exists -Path "C:\Windows"
True

User · Answer

This is my powershell newbie way of doing this if   Test-Path  quot   Desktop checkfile txt quot   -ne  quot True quot         Write-Host  quot Damn it quot    else       Write-Host  quot Yay quot

User · Answer

Another option is to use IO FileInfo which gives you so much file info it make life easier just using this type   PS  gt  mkdir C  Temp PS  gt  dir C  Temp  PS  gt   IO FileInfo   foo    C  Temp foo txt  PS  gt   foo Exists False PS  gt  New-TemporaryFile   Move-Item -Destination C  Temp foo txt PS  gt   foo Refresh   PS  gt   foo Exists True PS  gt   foo   Select-Object     Mode                -a---- VersionInfo         File              C  Temp foo txt                     InternalName                      OriginalFilename                      FileVersion                      FileDescription                      Product                      ProductVersion                      Debug             False                     Patched           False                     PreRelease        False                     PrivateBuild      False                     SpecialBuild      False                     Language   BaseName            foo Target                 LinkType            Length              0 DirectoryName       C  Temp Directory           C  Temp IsReadOnly          False FullName            C  Temp foo txt Extension            txt Name                foo txt Exists              True CreationTime        2 27 2019 8 57 33 AM CreationTimeUtc     2 27 2019 1 57 33 PM LastAccessTime      2 27 2019 8 57 33 AM LastAccessTimeUtc   2 27 2019 1 57 33 PM LastWriteTime       2 27 2019 8 57 33 AM LastWriteTimeUtc    2 27 2019 1 57 33 PM Attributes          Archive   More details on my blog

User · Answer

Add the following aliases  I think these should be made available in PowerShell by default  function not-exist   -not  Test-Path  args    Set-Alias  exist not-exist -Option  quot Constant  AllScope quot  Set-Alias exist Test-Path -Option  quot Constant  AllScope quot   With that  the conditional statements will change to  if  exist  path           and if  not-exist  path          if   exist  path

User · Answer

if  Test-Path C  DockerVol SelfCertSSL        write-host  quot Folder already exists  quot    else      New-Item -Path  quot C  DockerVol  quot  -Name  quot SelfCertSSL quot  -ItemType  quot directory quot

User · Answer

The alias solution you posted is clever  but I would argue against its use in scripts  for the same reason I don t like using any aliases in scripts  it tends to harm readability   If this is something you want to add to your profile so you can type out quick commands or use it as a shell  then I could see that making sense   You might consider piping instead     if   path   Test-Path          if  -not   path   Test-Path           if     path   Test-Path             Alternatively  for the negative approach  if appropriate for your code  you can make it a positive check then use else for the negative   if  Test-Path  path        throw  File already exists     else        The thing you really wanted to do

User · Answer

To check if a Path exists to a directory  use this one   pathToDirectory    quot c  program files blahblah  quot  if    System IO Directory   Exists  pathToDirectory      mkdir  path1    To check if a Path to a file exists use what  Mathias suggested   System IO File   Exists  pathToAFile

[powershell] A better way to check if a path exists or not in PowerShell

Examples related to powershell