How to Split Long Commands over Multiple Lines in Powershell

Another method for cleaner argument passing would be splatting.

Define your parameters and values as a hashtable like this:

$params = @{ 'class' = 'Win32_BIOS';
             'computername'='SERVER-R2';
             'filter'='drivetype=3';
             'credential'='Administrator' }

And then call your commandlet like this:

Get-WmiObject @params

Microsoft Docs: About Splatting

TechNet Magazine 2011: Windows PowerShell: Splatting

Looks like it works with Powershell 2.0 and up

Ah, and if you have a very long string that you want to break up, say of HTML, you can do it by putting a @ on each side of the outer " - like this:

$mystring = @"
Bob
went
to town
to buy
a fat
pig.
"@

You get exactly this:

Bob
went
to town
to buy
a fat
pig.

And if you are using Notepad++, it will even highlight correctly as a string block.

Now, if you wanted that string to contain double quotes, too, just add them in, like this:

$myvar = "Site"
$mystring = @"
<a href="">
Bob's $myvar
</a>
"@

You would get exactly this:

<a href="">
Bob's Site
</a>

However, if you use double-quotes in that @-string like that, Notepad++ doesn't realize that and will switch out the syntax colouring as if it were not quoted or quoted, depending on the case.

And what's better is this: anywhere you insert a $variable, it DOES get interpreted! (If you need the dollar sign in the text, you escape it with a tick mark like this: ``$not-a-variable`.)

NOTICE! If you don't put the final "@ at the very start of the line, it will fail. It took me an hour to figure out that I could not indent that in my code!

Here is MSDN on the subject: Using Windows PowerShell “Here-Strings”

You can use the backtick operator:

& "C:\Program Files\IIS\Microsoft Web Deploy\msdeploy.exe" `
    -verb:sync `
    -source:contentPath="c:\workspace\xxx\master\Build\_PublishedWebsites\xxx.Web" `
    -dest:contentPath="c:\websites\xxx\wwwroot\,computerName=192.168.1.1,username=administrator,password=xxx"

That's still a little too long for my taste, so I'd use some well-named variables:

$msdeployPath = "C:\Program Files\IIS\Microsoft Web Deploy\msdeploy.exe"
$verbArg = '-verb:sync'
$sourceArg = '-source:contentPath="c:\workspace\xxx\master\Build\_PublishedWebsites\xxx.Web"'
$destArg = '-dest:contentPath="c:\websites\xxx\wwwroot\,computerName=192.168.1.1,username=administrator,password=xxx"'

& $msdeployPath $verbArg $sourceArg $destArg

If you have a function:

$function:foo | % Invoke @(
  'bar'
  'directory'
  $true
)

If you have a cmdlet:

[PSCustomObject] @{
  Path  = 'bar'
  Type  = 'directory'
  Force = $true
} | New-Item

If you have an application:

{foo.exe @Args} | % Invoke @(
  'bar'
  'directory'
  $true
)

Or

icm {foo.exe @Args} -Args @(
  'bar'
  'directory'
  $true
)

In PowerShell 5 and PowerShell 5 ISE, it is also possible to use just Shift + Enter for multiline editing (instead of standard backticks ` at the end of each line):

PS> &"C:\Program Files\IIS\Microsoft Web Deploy\msdeploy.exe" # Shift+Enter
>>> -verb:sync # Shift+Enter
>>> -source:contentPath="c:\workspace\xxx\master\Build\_PublishedWebsites\xxx.Web" # Shift+Enter
>>> -dest:contentPath="c:\websites\xxx\wwwroot,computerName=192.168.1.1,username=administrator,password=xxx"

Another way to break a string across multiple lines is to put an empty expression in the middle of the string, and break it across lines:

sample string:

"stackoverflow stackoverflow stackoverflow stackoverflow stackoverflow"

broken across lines:

"stackoverflow stackoverflow $(
)stackoverflow stack$(
)overflow stackoverflow"

Splat Method with Calculations

If you choose splat method, beware calculations that are made using other parameters. In practice, sometimes I have to set variables first then create the hash table. Also, the format doesn't require single quotes around the key value or the semi-colon (as mentioned above).

Example of a call to a function that creates an Excel spreadsheet

$title = "Cut-off File Processing on $start_date_long_str"
$title_row = 1
$header_row = 2
$data_row_start = 3
$data_row_end = $($data_row_start + $($file_info_array.Count) - 1)

# use parameter hash table to make code more readable
$params = @{
    title = $title
    title_row = $title_row
    header_row = $header_row
    data_row_start = $data_row_start
    data_row_end = $data_row_end
}
$xl_wksht = Create-Excel-Spreadsheet @params

Note: The file array contains information that will affect how the spreadsheet is populated.