How can I pass the results of get-childitem into a command? - powershell

Question

I have several directories, subdirectories, etc in a directory structure and some of them will have various matching files. e.g. if X.config.default exists in a directory it will also have a corresponding X.config.build
c:\Stuff\dir1
web.config.default
web.config.build
c:\Stuff\dir2
app.config.default
app.config.build
c:\Stuff\dir2\sub2
foo.config.default
foo.config.build
bar.config.default
bar.config.build
This will display all file names matching *.config.default and their corresponding directory
get-childitem -Recurse *.* -Filter *.config.default | Select Name, Directory
But instead of displaying the files and their path, I want to do something for each "match". In this case I want to call a program called ctt and send it three arguments. ctt is called as follows:
ctt s:<source file> t:<transform file> d:<destination file>
Assume the first match is called fubar in directory c:\Stuff\dir1, the ctt command executed should look like:
ctt s:c:\Stuff\dir1\fubar.config.default t:c:\Stuff\dir1\fubar.config.build d:c:\Stuff\dir1\fubar.config pw
I'm guessing there are a few ways of doing this. Piping get-childitem results into a command, or sending them to some sort of collection on which I can do a foreach loop.
Thanks

Answer 1

There are a few different ways of approaching this. If you're on an older version of PowerShell, you'd most likely just use the ForEach-Object cmdlet.
Get-ChildItem -Path c:\Stuff\* -Recurse -Filter *.config.default |
ForEach-Object -Process {
$BuildName = $PSItem.Name.Split('.')[0] ### Get just the "fubar" part.
ctt s:"$($PSItem.FullName)" t:"$($PSItem.Directory.FullName)\$BuildName.config.build" d:"$($PSItem.Directory.FullName).config" pw
}
On newer versions of PowerShell, starting with 4.0, you can use the ForEach() method syntax.
http://social.technet.microsoft.com/wiki/contents/articles/26489.powershell-4-0-where-and-foreach-method-syntax.aspx
(Get-ChildItem -Path c:\Stuff\* -Recurse -Filter *.config.default).ForEach({
$BuildName = $PSItem.Name.Split('.')[0] ### Get just the "fubar" part.
ctt s:"$($PSItem.FullName)" t:"$($PSItem.Directory.FullName)\$BuildName.config.build" d:"$($PSItem.Directory.FullName).config" pw
}