Create directory if it does not exist

问题

I am writing a PowerShell script to create several directories if they do not exist.

The filesystem looks similar to this

D:\
D:\TopDirec\SubDirec\Project1\Revision1\Reports\
D:\TopDirec\SubDirec\Project2\Revision1\
D:\TopDirec\SubDirec\Project3\Revision1\

• Each project folder has multiple revisions.
• Each revision folder needs a Reports folder.
• Some of the "revisions" folders already contain a Reports folder; however, most do not.

I need to write a script that runs daily to create these folders for each directory.

I am able to write the script to create a folder, but creating several folders is problematic.

回答1:

Try the -Force parameter:

New-Item -ItemType Directory -Force -Path C:\Path\That\May\Or\May\Not\Exist

You can use Test-Path -PathType Container to check first.

See the New-Item MSDN help article for more details.

回答2:

$path = "C:\temp\NewFolder"
If(!(test-path $path))
{
      New-Item -ItemType Directory -Force -Path $path
}

Test-Path checks to see if the path exists. When it does not, it will create a new directory.

回答3:

I had the exact same problem. You can use something like this:

$local = Get-Location;
$final_local = "C:\Processing";

if(!$local.Equals("C:\"))
{
    cd "C:\";
    if((Test-Path $final_local) -eq 0)
    {
        mkdir $final_local;
        cd $final_local;
        liga;
    }

    ## If path already exists
    ## DB Connect
    elseif ((Test-Path $final_local) -eq 1)
    {
        cd $final_local;
        echo $final_local;
        liga;  (function created by you TODO something)
    }
}

回答4:

When you specify the -Force flag, PowerShell will not complain if the folder already exists.

One-liner:

Get-ChildItem D:\TopDirec\SubDirec\Project* | `
  %{ Get-ChildItem $_.FullName -Filter Revision* } | `
  %{ New-Item -ItemType Directory -Force -Path (Join-Path $_.FullName "Reports") }

BTW, for scheduling the task please check out this link: Scheduling Background Jobs.

回答5:

There are three ways I know to create a directory using PowerShell:

Method 1: PS C:\> New-Item -ItemType Directory -path "C:\livingston"

Method 2: PS C:\> [system.io.directory]::CreateDirectory("C:\livingston")

Method 3: PS C:\> md "C:\livingston"

回答6:

The following code snippet helps you to create a complete path.

Function GenerateFolder($path) {
    $global:foldPath = $null
    foreach($foldername in $path.split("\")) {
        $global:foldPath += ($foldername+"\")
        if (!(Test-Path $global:foldPath)){
            New-Item -ItemType Directory -Path $global:foldPath
            # Write-Host "$global:foldPath Folder Created Successfully"
        }
    }
}

The above function split the path you passed to the function and will check each folder whether it exists or not. If it does not exist it will create the respective folder until the target/final folder created.

To call the function, use below statement:

GenerateFolder "H:\Desktop\Nithesh\SrcFolder"

回答7:

From your situation it sounds like you need to create a "Revision#" folder once a day with a "Reports" folder in there. If that's the case, you just need to know what the next revision number is. Write a function that gets the next revision number, Get-NextRevisionNumber. Or you could do something like this:

foreach($Project in (Get-ChildItem "D:\TopDirec" -Directory)){
    # Select all the Revision folders from the project folder.
    $Revisions = Get-ChildItem "$($Project.Fullname)\Revision*" -Directory

    # The next revision number is just going to be one more than the highest number.
    # You need to cast the string in the first pipeline to an int so Sort-Object works.
    # If you sort it descending the first number will be the biggest so you select that one.
    # Once you have the highest revision number you just add one to it.
    $NextRevision = ($Revisions.Name | Foreach-Object {[int]$_.Replace('Revision','')} | Sort-Object -Descending | Select-Object -First 1)+1

    # Now in this we kill two birds with one stone.
    # It will create the "Reports" folder but it also creates "Revision#" folder too.
    New-Item -Path "$($Project.Fullname)\Revision$NextRevision\Reports" -Type Directory

    # Move on to the next project folder.
    # This untested example loop requires PowerShell version 3.0.
}

PowerShell 3.0 installation.

回答8:

I wanted to be able to easily let users create a default profile for PowerShell to override some settings, and ended up with the following one-liner (multiple statements yes, but can be pasted into PowerShell and executed at once, which was the main goal):

cls; [string]$filePath = $profile; [string]$fileContents = '<our standard settings>'; if(!(Test-Path $filePath)){md -Force ([System.IO.Path]::GetDirectoryName($filePath)) | Out-Null; $fileContents | sc $filePath; Write-Host 'File created!'; } else { Write-Warning 'File already exists!' };

For readability, here's how I would do it in a .ps1 file instead:

cls; # Clear console to better notice the results
[string]$filePath = $profile; # Declared as string, to allow the use of texts without plings and still not fail.
[string]$fileContents = '<our standard settings>'; # Statements can now be written on individual lines, instead of semicolon separated.
if(!(Test-Path $filePath)) {
  New-Item -Force ([System.IO.Path]::GetDirectoryName($filePath)) | Out-Null; # Ignore output of creating directory
  $fileContents | Set-Content $filePath; # Creates a new file with the input
  Write-Host 'File created!';
}
else {
  Write-Warning "File already exists! To remove the file, run the command: Remove-Item $filePath";
};

回答9:

Here's a simple one that worked for me. It checks whether the path exists, and if it doesn't, it will create not only the root path, but all sub-directories also:

$rptpath = "C:\temp\reports\exchange"

if (!(test-path -path $rptpath)) {new-item -path $rptpath -itemtype directory}

回答10:

Use:

$path = "C:\temp\"

If (!(test-path $path))
{
    md C:\Temp\
}

• The first line creates a variable named $path and assigns it the string value of "C:\temp\"

• The second line is an If statement which relies on the Test-Path cmdlet to check if the variable $path does not exist. The not exists is qualified using the ! symbol.

• Third line: If the path stored in the string above is not found, the code between the curly brackets will be run.

md is the short version of typing out: New-Item -ItemType Directory -Path $path

Note: I have not tested using the -Force parameter with the below to see if there is undesirable behavior if the path already exists.

New-Item -ItemType Directory -Path $path

来源：https://stackoverflow.com/questions/16906170/create-directory-if-it-does-not-exist