Start-Process

Starts one or more processes on the local computer.

Syntax

Start-Process
     [-FilePath] <string>
     [[-ArgumentList] <string[]>]
     [-Credential <pscredential>]
     [-WorkingDirectory <string>]
     [-LoadUserProfile]
     [-NoNewWindow]
     [-PassThru]
     [-RedirectStandardError <string>]
     [-RedirectStandardInput <string>]
     [-RedirectStandardOutput <string>]
     [-WindowStyle <ProcessWindowStyle>]
     [-Wait]
     [-UseNewEnvironment]
     [-Environment <hashtable>]
     [-WhatIf]
     [-Confirm]
     [<CommonParameters>]
Start-Process
     [-FilePath] <string>
     [[-ArgumentList] <string[]>]
     [-WorkingDirectory <string>]
     [-PassThru]
     [-Verb <string>]
     [-WindowStyle <ProcessWindowStyle>]
     [-Wait]
     [-Environment <hashtable>]
     [-WhatIf]
     [-Confirm]
     [<CommonParameters>]

Description

The Start-Process cmdlet starts one or more processes on the local computer. By default, Start-Process creates a new process that inherits all the environment variables that are defined in the current process.

To specify the program that runs in the process, enter an executable file or script file, or a file that can be opened using a program on the computer. If you specify a non-executable file, Start-Process starts the program that's associated with the file, similar to the Invoke-Item cmdlet.

You can use the parameters of Start-Process to specify options, such as loading a user profile, starting the process in a new window, or using alternate credentials.

Examples

Example 1: Start a process that uses default values

This example starts a process that uses the Sort.exe file in the current folder. The command uses all the default values, including the default window style, working folder, and credentials.

Start-Process -FilePath "sort.exe"

Example 2: Print a text file

This example starts a process that prints the C:\PS-Test\MyFile.txt file.

Start-Process -FilePath "myfile.txt" -WorkingDirectory "C:\PS-Test" -Verb Print

Example 3: Start a process to sort items to a new file

This example starts a process that sorts items in the TestSort.txt file and returns the sorted items in the Sorted.txt files. Any errors are written to the SortError.txt file. The UseNewEnvironment parameter specifies that the process runs with its own environment variables.

$processOptions = @{
    FilePath = "sort.exe"
    RedirectStandardInput = "TestSort.txt"
    RedirectStandardOutput = "Sorted.txt"
    RedirectStandardError = "SortError.txt"
    UseNewEnvironment = $true
}
Start-Process @processOptions

This example uses splatting to pass parameters to the cmdlet. For more information, see about_Splatting.

Example 4: Start a process in a maximized window

This example starts the Notepad.exe process. It maximizes the window and retains the window until the process completes.

Start-Process -FilePath "notepad" -Wait -WindowStyle Maximized

Example 5: Start PowerShell as an administrator

This example starts PowerShell using the Run as administrator option.

Start-Process -FilePath "powershell" -Verb RunAs

Example 6: Using different verbs to start a process

This example shows how to find the verbs that can be used when starting a process. The available verbs are determined by the filename extension of the file that runs in the process.

$startExe = New-Object System.Diagnostics.ProcessStartInfo -Args powershell.exe
$startExe.verbs

open
runas
runasuser

The example uses New-Object to create a System.Diagnostics.ProcessStartInfo object for powershell.exe, the file that runs in the PowerShell process. The Verbs property of the ProcessStartInfo object shows that you can use the Open and RunAs verbs with powershell.exe, or with any process that runs a .exe file.

Example 7: Specifying arguments to the process

Both commands start the Windows command interpreter, issuing a dir command on the Program Files folder. Because this foldername contains a space, the value needs surrounded with escaped quotes. Note that the first command specifies a string as ArgumentList. The second command is a string array.

Start-Process -FilePath "$env:comspec" -ArgumentList "/c dir `"%SystemDrive%\Program Files`""
Start-Process -FilePath "$env:comspec" -ArgumentList "/c","dir","`"%SystemDrive%\Program Files`""

Example 8: Create a detached process on Linux

On Windows, Start-Process creates an independent process that remains running independently of the launching shell. On non-Windows platforms, the newly started process is attached to the shell that launched. If the launching shell is closed, the child process is terminated.

To avoid terminating the child process on Unix-like platforms, you can combine Start-Process with nohup. The following example launches a background instance of PowerShell on Linux that stays alive even after you close the launching session. The nohup command collects output in file nohup.out in the current directory.

# Runs for 2 minutes and appends output to ./nohup.out
Start-Process nohup 'pwsh -noprofile -c "1..120 | % { Write-Host . -NoNewline; sleep 1 }"'

In this example, Start-Process is running the Linux nohup command, which launches pwsh as a detached process. For more information, see the nohup article on Wikipedia.

Example 9: Overriding an environment variable for a process

By default, when you use Start-Process, the new process is created with the same environment variables as the current session. You can use the Environment parameter to override the values of those variables.

In this example, the environment variable FOO is added to the session with foo as the value.

The example runs Start-Process three times, returning the value of FOO each time. The first command doesn't override the environment variable. In the second command, FOO is set to bar. In the third command, FOO is set to $null, which removes it.

$env:FOO = 'foo'
Start-Process pwsh -NoNewWindow -ArgumentList '-c', '$env:FOO'
Start-Process pwsh -NoNewWindow -ArgumentList '-c', '$env:FOO' -Environment @{
    FOO  = 'bar'
}
Start-Process pwsh -NoNewWindow -ArgumentList '-c', '$env:FOO' -Environment @{
    FOO  = $null
}

foo
bar

Parameters

-ArgumentList

Specifies parameters or parameter values to use when this cmdlet starts the process. Arguments can be accepted as a single string with the arguments separated by spaces, or as an array of strings separated by commas. The cmdlet joins the array into a single string with each element of the array separated by a single space.

The outer quotes of the PowerShell strings aren't included when the ArgumentList values are passed to the new process. If parameters or parameter values contain a space or quotes, they need to be surrounded with escaped double quotes. For more information, see about_Quoting_Rules.

For the best results, use a single ArgumentList value containing all the arguments and any needed quote characters.

Type:String[]
Aliases:Args
Position:1
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-Confirm

Prompts you for confirmation before running the cmdlet.

Type:SwitchParameter
Aliases:cf
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-Credential

Specifies a user account that has permission to perform this action. By default, the cmdlet uses the credentials of the current user.

Type a user name, such as User01 or Domain01\User01, or enter a PSCredential object generated by the Get-Credential cmdlet. If you type a user name, you're prompted to enter the password.

Credentials are stored in a PSCredential object and the password is stored as a SecureString.

Note

For more information about SecureString data protection, see How secure is SecureString?.

Type:PSCredential
Aliases:RunAs
Position:Named
Default value:Current user
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-Environment

Specifies one or more environment variables to override for the process as a hash table. Specify the name of an environment variable as a key in the hash table and the desired value. To unset an environment variable, specify its value as $null.

The specified variables are replaced in the process. When you specify the PATH environment variable it's replaced with the value of $PSHOME followed by the specified value from this parameter. On Windows, the command appends the values for PATH in the Machine and User scopes after the new value.

This parameter was added in PowerShell 7.4.

Type:Hashtable
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-FilePath

Specifies the optional path and filename of the program that runs in the process. Enter the name of an executable file or of a document, such as a .txt or .doc file, that's associated with a program on the computer. This parameter is required.

If you specify only a filename that does not correspond to a system command, use the WorkingDirectory parameter to specify the path.

Type:String
Aliases:PSPath, Path
Position:0
Default value:None
Required:True
Accept pipeline input:False
Accept wildcard characters:False

-LoadUserProfile

Indicates that this cmdlet loads the Windows user profile stored in the HKEY_USERS registry key for the current user. The parameter doesn't apply to non-Windows systems.

This parameter doesn't affect the PowerShell profiles. For more information, see about_Profiles.

Type:SwitchParameter
Aliases:Lup
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-NoNewWindow

Start the new process in the current console window. By default on Windows, PowerShell opens a new window. On non-Windows systems, you never get a new window.

You can't use the NoNewWindow and WindowStyle parameters in the same command.

The parameter doesn't apply to non-Windows systems.

Type:SwitchParameter
Aliases:nnw
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-PassThru

Returns a process object for each process that the cmdlet started. By default, this cmdlet doesn't generate any output.

Type:SwitchParameter
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-RedirectStandardError

Specifies a file. This cmdlet sends any errors generated by the process to a file that you specify. Enter the path and filename. By default, the errors are displayed in the console.

Type:String
Aliases:RSE
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-RedirectStandardInput

Specifies a file. This cmdlet reads input from the specified file. Enter the path and filename of the input file. By default, the process gets its input from the keyboard.

Type:String
Aliases:RSI
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-RedirectStandardOutput

Specifies a file. This cmdlet sends the output generated by the process to a file that you specify. Enter the path and filename. By default, the output is displayed in the console.

Type:String
Aliases:RSO
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-UseNewEnvironment

Indicates that this cmdlet uses new environment variables specified for the process. By default, the started process runs with the environment variables inherited from the parent process.

On Windows, when you use UseNewEnvironment, the new process starts only containing the default environment variables defined for the Machine scope. This has the side effect that the $env:USERNAME is set to SYSTEM. None of the variables from the User scope are included.

Type:SwitchParameter
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-Verb

Specifies a verb to use when this cmdlet starts the process. The verbs that are available are determined by the filename extension of the file that runs in the process.

The following table shows the verbs for some common process file types.

File type Verbs
.cmd Edit, Open, Print, RunAs, RunAsUser
.exe Open, RunAs, RunAsUser
.txt Open, Print, PrintTo
.wav Open, Play

To find the verbs that can be used with the file that runs in a process, use the New-Object cmdlet to create a System.Diagnostics.ProcessStartInfo object for the file. The available verbs are in the Verbs property of the ProcessStartInfo object. For details, see the examples.

The parameter doesn't apply to non-Windows systems.

Type:String
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-Wait

Indicates that this cmdlet waits for the specified process and its descendants to complete before accepting more input. This parameter suppresses the command prompt or retains the window until the processes finish.

Type:SwitchParameter
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-WhatIf

Shows what would happen if the cmdlet runs. The cmdlet isn't run.

This parameter was introduced in PowerShell 6.0.

Type:SwitchParameter
Aliases:wi
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-WindowStyle

Specifies the state of the window that's used for the new process. The default value is Normal. The acceptable values for this parameter are:

  • Normal
  • Hidden
  • Minimized
  • Maximized

You can't use the WindowStyle and NoNewWindow parameters in the same command.

The parameter doesn't apply to non-Windows systems. When using on non-Windows systems, you never get a new window.

Type:ProcessWindowStyle
Accepted values:Normal, Hidden, Minimized, Maximized
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

-WorkingDirectory

Specifies the location that the new process should start in.

When not specified, the cmdlet defaults to the fully-qualified location specified in the FilePath parameter. If the value of the FilePath parameter is not fully-qualified, it defaults to the current working directory of the calling process.

Wildcards aren't supported. The path must not contain characters that would be interpreted as wildcards.

Type:String
Position:Named
Default value:None
Required:False
Accept pipeline input:False
Accept wildcard characters:False

Inputs

None

You can't pipe objects to this cmdlet.

Outputs

None

By default, this cmdlet returns no output.

Process

When you use the PassThru parameter, this cmdlet returns a Process object.

Notes

PowerShell includes the following aliases for Start-Process:

  • All platforms
    • saps
  • Windows
    • start

Native commands are executable files installed in the operating system. These executables can be run from any command-line shell, like PowerShell. Usually you run the command exactly as you would in bash or cmd.exe. The Start-Process cmdlet can be used to run any native commands, but should only be used when you need to control how the command is executed.

Start-Process is useful for running GUI programs on non-Windows platforms. For example, run Start-Process gedit to launch the graphical text editor common the GNOME Desktop environments.

By default, Start-Process launches a process asynchronously. Control is instantly returned to PowerShell even if the new process is still running.

  • On the local system, the launched process lives on independent from the calling process.
  • On a remote system, the new process is terminated when the remote session ends, immediately following the Start-Process command. Therefore, you can't use Start-Process in a remote session expecting the launched process to outlive the session.

If you do need to use Start-Process in a remote session, invoke it with the Wait parameter. Or you could use other methods to create a new process on the remote system.

When using the Wait parameter, Start-Process waits for the process tree (the process and all its descendants) to exit before returning control. This is different than the behavior of the Wait-Process cmdlet, which only waits for the specified processes to exit.

On Windows, the most common use case for Start-Process is to use the Wait parameter to block progress until the new process exits. On non-Windows system, this is rarely needed since the default behavior for command-line applications is equivalent to Start-Process -Wait.

This cmdlet is implemented using the Start method of the System.Diagnostics.Process class. For more information about this method, see Process.Start Method.