How to call batch script from Powershell?

Question

I have one big batch script which sets bunch of environment variables. I want to call that batch script from powershell, that way I can get benefits of both i.e. enviorment variable set by my script and powershell.

Answer 1

If you grab the PowerShell Community Extensions, there is an Invoke-BatchFile command in it that runs the batch file but more importantly, it retains any environment variable modifications made by the batch file e.g.:

>Invoke-BatchFile 'C:\Program Files (x86)\Microsoft Visual Studio 9.0\VC\vcvarsall.bat'
Setting environment for using Microsoft Visual Studio 2008 x86 tools.

Answer 2

The idea comes from this blog post: Nothing solves everything – PowerShell and other technologies

Here is my version of this script. It calls a batch file (or any native command) and propagates its environment:

---

UPDATE: Improved and better tested version of this script is here: Invoke-Environment.ps1

<#
.SYNOPSIS
    Invokes a command and imports its environment variables.

.DESCRIPTION
    It invokes any cmd shell command (normally a configuration batch file) and
    imports its environment variables to the calling process. Command output is
    discarded completely. It fails if the command exit code is not 0. To ignore
    the exit code use the 'call' command.

.PARAMETER Command
        Any cmd shell command, normally a configuration batch file.

.EXAMPLE
    # Invokes Config.bat in the current directory or the system path
    Invoke-Environment Config.bat

.EXAMPLE
    # Visual Studio environment: works even if exit code is not 0
    Invoke-Environment 'call "%VS100COMNTOOLS%\vsvars32.bat"'

.EXAMPLE
    # This command fails if vsvars32.bat exit code is not 0
    Invoke-Environment '"%VS100COMNTOOLS%\vsvars32.bat"'
#>

param
(
    [Parameter(Mandatory=$true)] [string]
    $Command
)

cmd /c "$Command > nul 2>&1 && set" | .{process{
    if ($_ -match '^([^=]+)=(.*)') {
        [System.Environment]::SetEnvironmentVariable($matches[1], $matches[2])
    }
}}

if ($LASTEXITCODE) {
    throw "Command '$Command': exit code: $LASTEXITCODE"
}

---

P.S. Here is the proposal to add similar capability to PowerShell: Extend dot sourcing concept to cmd files

Answer 3

Is it possible to convert your batch script to PowerShell script? If you run the bat file, its is executed in separate session that doesn't modify PowerShell's env variables.

You can work with env variables very smoothly:

PS> Get-ChildItem env:

Name                           Value
----                           -----
ALLUSERSPROFILE                C:\ProgramData
APPDATA                        C:\Users\xyz\AppData\Roaming
CommonProgramFiles             C:\Program Files (x86)\Common Files
CommonProgramFiles(x86)        C:\Program Files (x86)\Common Files
CommonProgramW6432             C:\Program Files\Common Files
COMPUTERNAME                   xyz
ComSpec                        C:\Windows\system32\cmd.exe
DXSDK_DIR                      D:\prgs\dev\Microsoft DirectX SDK (August 2009)\
FP_NO_HOST_CHECK               NO
HOMEDRIVE                      Z:
HOMEPATH                       \
...

PS> Get-Item env:path
Name  Value
----  -----
Path  c:\dev\CollabNet\SubversionClient;C:\Windows\system32;...

Or even (much shorter, returns only string):

PS> $env:path
c:\dev\CollabNet\Subversion Client;C:\Windows\system32;...

You can change the environment path like this:

PS> $env:path += ";c:\mydir"

And you can even set environment variables at machine level like this:

# fist arg = env variable name, second = value, third = level, available are 'Process', 'User', 'Machine'
PS> [Environment]::SetEnvironmentVariable('test', 'value', 'machine')

Answer 4

@Roman Kuzmin's solution works great, but piping the command output to nul can kind of leave you in the dark. So I made a few tweaks to allow for the command output to display normally, and instead pipe the env vars to a temp file to read in afterwards:

param
(
    [Parameter(Mandatory=$true)] [string]
    $Command
)
$VarsPath = [IO.Path]::GetTempFileName()
cmd /c "$Command && set > $VarsPath"
if (-not $LASTEXITCODE) {
    Get-Content $VarsPath | ForEach-Object {
        if ($_ -match '^([^=]+)=(.*)') {
            [System.Environment]::SetEnvironmentVariable($matches[1], $matches[2])
        }
    }
}
Remove-Item $VarsPath

Answer 5

You can run a batch script from Powershell just by putting its name, but that won't help you. Environment variables set in the batch script will only be visible from that batch and anything that batch runs. Once the control returns back to Powershell the environment variables are gone. You could have the batch script run set at the end and then parse its output into your PSH environment variables, though.