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

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

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.
}

To check if a Path exists to a directory, use this one:

$pathToDirectory = "c:\program files\blahblah\"
if (![System.IO.Directory]::Exists($pathToDirectory))
{
 mkdir $path1
}

To check if a Path to a file exists use what @Mathias suggested:

[System.IO.File]::Exists($pathToAFile)

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 "Constant, AllScope"
Set-Alias exist Test-Path -Option "Constant, AllScope"

With that, the conditional statements will change to:

if (exist $path) { ... }

and

if (not-exist $path) { ... }
if (!exist $path) { ... }

if (Test-Path C:\DockerVol\SelfCertSSL) {
    write-host "Folder already exists."
} else {
   New-Item -Path "C:\DockerVol\" -Name "SelfCertSSL" -ItemType "directory"
}

Another option is to use IO.FileInfo which gives you so much file info it make life easier just using this type:

PS > mkdir C:\Temp
PS > dir C:\Temp\
PS > [IO.FileInfo] $foo = 'C:\Temp\foo.txt'
PS > $foo.Exists
False
PS > New-TemporaryFile | Move-Item -Destination C:\Temp\foo.txt
PS > $foo.Refresh()
PS > $foo.Exists
True
PS > $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.

This is my powershell newbie way of doing this

if ((Test-Path ".\Desktop\checkfile.txt") -ne "True") {
    Write-Host "Damn it"
} else {
    Write-Host "Yay"
}