How to enter a multi-line command

Question

Is it possible to split a PowerShell command line over multiple lines?

In Visual Basic I can use the underscore (_) to continue the command in the next line.

Answer 1

You can use a space followed by the grave accent (backtick):

Get-ChildItem -Recurse `
  -Filter *.jpg `
  | Select LastWriteTime

However, this is only ever necessary in such cases as shown above. Usually you get automatic line continuation when a command cannot syntactically be complete at that point. This includes starting a new pipeline element:

Get-ChildItem |
  Select Name,Length

will work without problems since after the | the command cannot be complete since it's missing another pipeline element. Also opening curly braces or any other kind of parentheses will allow line continuation directly:

$x=1..5
$x[
  0,3
] | % {
  "Number: $_"
}

Similar to the | a comma will also work in some contexts:

1,
2

Keep in mind, though, similar to JavaScript's Automatic Semicolon Insertion, there are some things that are similarly broken because the line break occurs at a point where it is preceded by a valid statement:

return
  5

will not work.

Finally, strings (in all varieties) may also extend beyond a single line:

'Foo
bar'

They include the line breaks within the string, then.

Answer 2

In most C-like languages I am deliberate about placing my braces where I think they make the code easiest to read.

PowerShell's parser recognizes when a statement clearly isn't complete, and looks to the next line. For example, imagine a cmdlet that takes an optional script block parameter:

    Get-Foo { ............ }

if the script block is very long, you might want to write:

    Get-Foo
    {
        ...............
        ...............
        ...............
    }

But this won't work: the parser will see two statements. The first is Get-Foo and the second is a script block. Instead, I write:

    Get-Foo {
        ...............
        ...............
        ...............
    }

I could use the line-continuation character (`) but that makes for hard-to-read code, and invites bugs.

Because this case requires the open brace to be on the previous line, I follow that pattern everywhere:

    if (condition) {
        .....
    }

Note that if statements require a script block in the language grammar, so the parser will look on the next line for the script block, but for consistency, I keep the open brace on the same line.

Simlarly, in the case of long pipelines, I break after the pipe character (|):

    $project.Items | 
        ? { $_.Key -eq "ProjectFile" } | 
        % { $_.Value } | 
        % { $_.EvaluatedInclude } |
        % {
            .........
        }

Answer 3

To expand on cristobalito's answer:

I assume you're talking about on the command-line - if it's in a script, then a new-line >acts as a command delimiter.

On the command line, use a semi-colon ';'

For example:

Sign a PowerShell script on the command-line. No line breaks.

powershell -Command "&{$cert=Get-ChildItem –Path cert:\CurrentUser\my -codeSigningCert ; Set-AuthenticodeSignature -filepath Z:\test.ps1 -Cert $cert}

Answer 4

1. Use a semi-colon ; to separate command
2. Replace double backslash \\ on any backslashes \.
3. Use "' for passing safe address to switch command like "'PATH'".

This ps1 command install locale pfx certificate.

powershell -Command "$pfxPassword = ConvertTo-SecureString -String "12345678" -Force -AsPlainText ; Import-PfxCertificate -FilePath "'C:\\Program Files\\VpnManagement\\resources\\assets\\cert\\localhost.pfx'" Cert:\\LocalMachine\\My -Password $pfxPassword ; Import-PfxCertificate -FilePath "'C:\\Program Files\\VpnManagement\\resources\\assets\\cert\\localhost.pfx'" Cert:\\LocalMachine\\Root -Password $pfxPassword"

Answer 5

I just found out that there must not be any character between the back tick and the line break. Even whitespace will cause the command to not work.

Answer 6

I assume you're talking about on the command-line - if it's in a script, then a new-line acts as a command delimiter.

On the command line, use a semi-colon ';'