Equivalent of *Nix 'which' command in PowerShell?

Question

How do I ask PowerShell where something is?

For instance, "which notepad" and it returns the directory where the notepad.exe is run from according to the current paths.

Answer 1

The very first alias I made once I started customizing my profile in PowerShell was 'which'.

New-Alias which get-command

To add this to your profile, type this:

"`nNew-Alias which get-command" | add-content $profile

The `n at the start of the last line is to ensure it will start as a new line.

Answer 2

Here is an actual *nix equivalent, i.e. it gives *nix-style output.

Get-Command <your command> | Select-Object -ExpandProperty Definition

Just replace with whatever you're looking for.

PS C:\> Get-Command notepad.exe | Select-Object -ExpandProperty Definition
C:\Windows\system32\notepad.exe

When you add it to your profile, you will want to use a function rather than an alias because you can't use aliases with pipes:

function which($name)
{
    Get-Command $name | Select-Object -ExpandProperty Definition
}

Now, when you reload your profile you can do this:

PS C:\> which notepad
C:\Windows\system32\notepad.exe

Answer 3

I usually just type:

gcm notepad

or

gcm note*

gcm is the default alias for Get-Command.

On my system, gcm note* outputs:

[27] » gcm note*

CommandType     Name                                                     Definition
-----------     ----                                                     ----------
Application     notepad.exe                                              C:\WINDOWS\notepad.exe
Application     notepad.exe                                              C:\WINDOWS\system32\notepad.exe
Application     Notepad2.exe                                             C:\Utils\Notepad2.exe
Application     Notepad2.ini                                             C:\Utils\Notepad2.ini

You get the directory and the command that matches what you're looking for.

Answer 4

Try this example:

(Get-Command notepad.exe).Path

Answer 5

This seems to do what you want (I found it on http://huddledmasses.org/powershell-find-path/):

Function Find-Path($Path, [switch]$All = $false, [Microsoft.PowerShell.Commands.TestPathType]$type = "Any")
## You could comment out the function stuff and use it as a script instead, with this line:
#param($Path, [switch]$All = $false, [Microsoft.PowerShell.Commands.TestPathType]$type = "Any")
   if($(Test-Path $Path -Type $type)) {
      return $path
   } else {
      [string[]]$paths = @($pwd);
      $paths += "$pwd;$env:path".split(";")

      $paths = Join-Path $paths $(Split-Path $Path -leaf) | ? { Test-Path $_ -Type $type }
      if($paths.Length -gt 0) {
         if($All) {
            return $paths;
         } else {
            return $paths[0]
         }
      }
   }
   throw "Couldn't find a matching path of type $type"
}
Set-Alias find Find-Path

Answer 6

Check this PowerShell Which.

The code provided there suggests this:

($Env:Path).Split(";") | Get-ChildItem -filter notepad.exe

Answer 7

My proposition for the Which function:

function which($cmd) { get-command $cmd | % { $_.Path } }

PS C:\> which devcon

C:\local\code\bin\devcon.exe

Answer 8

Try the where command on Windows 2003 or later (or Windows 2000/XP if you've installed a Resource Kit).

BTW, this received more answers in other questions:

Is there an equivalent of 'which' on Windows?

PowerShell equivalent to Unix which command?

Answer 9

A quick-and-dirty match to Unix which is

New-Alias which where.exe

But it returns multiple lines if they exist so then it becomes

$(where.exe command | select -first 1)

Answer 10

I like Get-Command | Format-List, or shorter, using aliases for the two and only for powershell.exe:

gcm powershell | fl

You can find aliases like this:

alias -definition Format-List

Tab completion works with gcm.

Answer 11

I have this which advanced function in my PowerShell profile:

function which {
<#
.SYNOPSIS
Identifies the source of a PowerShell command.
.DESCRIPTION
Identifies the source of a PowerShell command. External commands (Applications) are identified by the path to the executable
(which must be in the system PATH); cmdlets and functions are identified as such and the name of the module they are defined in
provided; aliases are expanded and the source of the alias definition is returned.
.INPUTS
No inputs; you cannot pipe data to this function.
.OUTPUTS
.PARAMETER Name
The name of the command to be identified.
.EXAMPLE
PS C:\Users\Smith\Documents> which Get-Command

Get-Command: Cmdlet in module Microsoft.PowerShell.Core

(Identifies type and source of command)
.EXAMPLE
PS C:\Users\Smith\Documents> which notepad

C:\WINDOWS\SYSTEM32\notepad.exe

(Indicates the full path of the executable)
#>
    param(
    [String]$name
    )

    $cmd = Get-Command $name
    $redirect = $null
    switch ($cmd.CommandType) {
        "Alias"          { "{0}: Alias for ({1})" -f $cmd.Name, (. { which cmd.Definition } ) }
        "Application"    { $cmd.Source }
        "Cmdlet"         { "{0}: {1} {2}" -f $cmd.Name, $cmd.CommandType, (. { if ($cmd.Source.Length) { "in module {0}" -f $cmd.Source} else { "from unspecified source" } } ) }
        "Function"       { "{0}: {1} {2}" -f $cmd.Name, $cmd.CommandType, (. { if ($cmd.Source.Length) { "in module {0}" -f $cmd.Source} else { "from unspecified source" } } ) }
        "Workflow"       { "{0}: {1} {2}" -f $cmd.Name, $cmd.CommandType, (. { if ($cmd.Source.Length) { "in module {0}" -f $cmd.Source} else { "from unspecified source" } } ) }
        "ExternalScript" { $cmd.Source }
        default          { $cmd }
    }
}

Answer 12

Use:

function Which([string] $cmd) {
  $path = (($Env:Path).Split(";") | Select -uniq | Where { $_.Length } | Where { Test-Path $_ } | Get-ChildItem -filter $cmd).FullName
  if ($path) { $path.ToString() }
}

# Check if Chocolatey is installed
if (Which('cinst.bat')) {
  Write-Host "yes"
} else {
  Write-Host "no"
}

Or this version, calling the original where command.

This version also works better, because it is not limited to bat files:

function which([string] $cmd) {
  $where = iex $(Join-Path $env:SystemRoot "System32\where.exe $cmd 2>&1")
  $first = $($where -split '[\r\n]')
  if ($first.getType().BaseType.Name -eq 'Array') {
    $first = $first[0]
  }
  if (Test-Path $first) {
    $first
  }
}

# Check if Curl is installed
if (which('curl')) {
  echo 'yes'
} else {
  echo 'no'
}