How do I use Join-Path to combine more than two strings into a file path

Question

If I want to combine two strings into a file path  I use Join-Path like this    path   Join-Path C   Program Files  Write-Host  path   That prints  C  Program Files   If I want to do this for more than two strings though    path   Join-Path C   Program Files   Microsoft Office  Write-Host  path   PowerShell throws an error      Join-Path   A positional parameter cannot be found that accepts argument  Microsoft Office          At D  users ma my script ps1 1 char 18           path   join-path  lt  lt  lt  lt   C   Program Files   Microsoft Office               CategoryInfo            InvalidArgument       Join-Path   ParameterBindingException              FullyQualifiedErrorId   PositionalParameterNotFound Microsoft PowerShell            Commands JoinPathCommand   I tried using a string array    string     pieces    C     Program Files    Microsoft Office   path   Join-Path  pieces Write-Host  path   But PowerShell prompts me to enter the childpath  since I didn t specify the -childpath argument   e g   somepath   and then creates three files paths   C  somepath Program Files somepath Microsoft Office somepath   which isn t right either

User · Answer

If you are still using  NET 2 0  then  IO Path   Combine won t have the params string   overload which you need to join more than two parts  and you ll see the error Cannot find an overload for  Combine  and the argument count   3    Slightly less elegant  but a pure PowerShell solution is to manually aggregate path parts   Join-Path C   Join-Path   Program Files   Microsoft Office     or  Join-Path   Join-Path  C   Program Files    Microsoft Office

User · Answer

The following approach is more concise than piping Join-Path statements    p    a    b    c    d    ForEach-Object -Process    p   Join-Path  p         p then holds the concatenated path  a b c d     I just noticed that this is the exact same approach as Mike Fair s  sorry

User · Answer

Since PowerShell 6 0  Join-Path has a new parameter called -AdditionalChildPath and can combine multiple parts of a path out-of-the-box  Either by providing the extra parameter or by just supplying a list of elements   Example from the documentation   Join-Path a b c d e f g a b c d e f g   So in PowerShell 6 0 and above your variant   path   Join-Path C   Program Files   Microsoft Office    works as expected

User · Answer

Join-Path is not exactly what you are looking for  It has multiple uses but not the one you are looking for  An example from Partying with Join-Path   Join-Path C  hello d  goodbye e  hola f  adios world C  hello world d  goodbye world e  hola world f  adios world   You see that it accepts an array of strings  and it concatenates the child string to each creating full paths  In your example   path   join-path C   Program Files   Microsoft Office   You are getting the error since you are passing three positional arguments and join-path only accepts two  What you are looking for is a -join  and I could see this being a misunderstanding  Consider instead this with your example    C    Program Files   Microsoft Office  -join       -Join takes the array of items and concatenates them with   into a single string   C  Program Files Microsoft Office   Minor attempt at a salvage  Yes  I will agree that this answer is better  but mine could still work  Comments suggest there could be an issue with slashes  so to keep with my concatenation approach you could do this as well    C      Program Files    Microsoft Office   -join     -replace            2          So if there are issues with extra slashes it could be handled as long as they are not in the beginning of the string  allows UNC paths    io path   combine  c      foo     bar    would not work as expected and mine would account for that  Both require proper strings for input as you cannot account for all scenarios  Consider both approaches  but  yes  the other higher-rated answer is more terse  and I didn t even know it existed   Also  would like to point out  my answer explains how what the OP doing was wrong on top of providing a suggestion to address the core problem

User · Answer

Here s something that will do what you d want when using a string array for the ChildPath    path    C       Program Files    Microsoft Office          path   Join-Path  path      Write-Host  path   Which outputs   C  Program Files Microsoft Office   The only caveat I found is that the initial value for  path must have a value  cannot be null or empty

User · Answer

Or you could write your own function for it  which is what I ended up doing    function Join-Path-Recursively  PathParts         NumberOfPathParts    PathParts Length       if   NumberOfPathParts -eq 0            return  null       elseif   NumberOfPathParts -eq 1            return  PathParts 0        else           return Join-Path -Path  PathParts 0  -ChildPath   Join-Path-Recursively -PathParts  PathParts 1    NumberOfPathParts-1              You could then call the function like this   Join-Path-Recursively -PathParts     C     Program Files    Microsoft Office   Join-Path-Recursively     C     Program Files    Microsoft Office     This has the advantage of having the exact same behaviour as the normal Join-Path function and not depending on the  NET Framework

User · Answer

You can use the  NET Path class    IO Path   Combine  C      Foo    Bar

User · Answer

Since Join-Path can be piped a path value  you can pipe multiple Join-Path statements together   Join-Path  C   -ChildPath  Windows    Join-Path -ChildPath  system32    Join-Path -ChildPath  drivers    It s not as terse as you would probably like it to be  but it s fully PowerShell and is relatively easy to read

User · Answer

Here are two more ways to write a pure PowerShell function to join an arbitrary number of components into a path   This first function uses a single array to store all of the components and then a foreach loop to combine them   function Join-Paths       Param           Parameter mandatory            String             Paths            output    Paths 0      foreach  path in  Paths 1   Paths Count              output   Join-Path  output -ChildPath  path            output     Because the path components are elements in an array and all part of a single argument  they must be separated by commas  Usage is as follows    PS C    Join-Paths  C     Program Files    Microsoft Office  C  Program Files Microsoft Office     A more minimalist way to write this function is to use the built-in  args variable  and then collapse the foreach loop into a single line using Mike Fair s method   function Join-Paths2        path    args 0       args 1   args Count        path   Join-Path  path           path     Unlike the previous version of the function  each path component is a separate argument  so only a space is necessary to separate the arguments    PS C    Join-Paths2  C    Program Files   Microsoft Office  C  Program Files Microsoft Office

User · Answer

You can use it this way    root    C    folder1    Program Files  x86    folder2    Microsoft NET   if  -Not Test-Path   Join-Path  root -ChildPath  folder1   Join-Path -ChildPath  folder2          Folder does not exist    else        Folder exist

[powershell] How do I use Join-Path to combine more than two strings into a file path?

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