How to pass a list of files as parameters to a powershell script

Question

How does one pass a list of files as parameters to a Powershell script?

param
(
    [String[]]$files
)

echo $files

When I try to run it

PS D:\> & '.\merge outputs.ps1' *.dat

it prints

*.dat

but I expected something similar to

file1.dat
file2.dat
...
fileN.dat

Answer 1

The two solutions presented thusfar (even though one is accepted and both have upvotes) do not really provide an adequate solution to the question--they both make you jump through hoops. The question as posed stated that by just putting *.dat on the commmand line, how can one make the underlying code treat it like you would expect. That is, how to make the code simply do the right thing. With other shells and other cmdlets, all you do is *.dat, not like this:

foobar(fizzbuzz[--brobdingnag*!& '\''*.dat''`])

(OK, I exaggerate to make a point:-) But there is an easy way to just do the right thing--check if wildcards are used and then just expand them:

param
(
    [String[]]$files
)
$IsWP = [System.Management.Automation.WildcardPattern]::ContainsWildcardCharacters($files)
if($IsWP) { 
    $files = Get-ChildItem $files | % { $_.Name }
}
echo $files

Answer 2

You can either pass full file name as string

& '.\merge outputs' -files (dir *.dat | %{ $_.FullName })

Or you can accept FileSystemInfo param in your script

param
(
    [System.IO.FileSystemInfo[]]$files
)

Write-Host $files

And call:

& '.\merge outputs' -files (dir *.dat)

Answer 3

$files = dir *.dat | foreach {$_.fullname}

& '.\merge outputs.ps1' -files $files