Powershell - avoid repeating arguments of Out-File

Question

Is there any way to avoid passing parameters to a function, like "-Append $outfile" to Out-File, every time? I have a script which collects data from the system, something like:

... collect OS information ... | Out-File -Append $output
... collect local users ... | Out-File -Append $output
... collect logfile permissions ... | Out-File -Append $output
etc.

The last command in the pipe is most of the time Out-File -Append $output - can this be done more elegant? I had different ideas:

Create a wrapper function which passes the needed parameters to Out-File command - already tried, but I had problems to make it pipe-compatible
Write all output into a String-Variable and write the content at the end of all commands into the file - needs a lot of memory
Create something like an Output-Writer-Object which only receives once at initialization the necessary paramters - not tried yet

Thank you very much for your help!

@Avshalom Is ">> $output" absolutely equivalent to "Out-File -Append $output"? — Patrick, Oct 28 '15 at 12:19

score 0 · Accepted Answer · edited May 23 '17 at 12:23

0

You dont appear to be using a lot of arguments for this to be incredibly useful but a good suggestion would be to use splatting. I added some more parameters to illustrate how clean it can make code appear while still being functional.

$options = @{
    Append = $True
    FilePath = $output
    Encoding = "Unicode"
    Width = 400
}

Build a hastable of options and splat the cmdlet with them

... collect OS information ... | Out-File  @options
... collect local users ... | Out-File  @options
... collect logfile permissions ... | Out-File @options

Outside of that a wrapper function (of filter if it is easier) like you suggest would be another option. Look at the options in this answer. Specifically the filter

edited May 23 '17 at 12:23

Community

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answered Oct 28 '15 at 12:13

Matt

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`-Append` is switch parameter, so it will be just `$true`, and `$output` goes to first positional parameter `-FilePath`. – user4003407 Oct 28 '15 at 12:19
@PetSerAl fixed. Thanks. – Matt Oct 28 '15 at 12:21

score 0 · Answer 2 · answered May 24 '22 at 11:40

You want to use the $PSDefaultParameterValues preference variable. Something like this:

$PSDefaultParameterValues = @{
    "Out-File:Encoding"="utf8";
    "Out-File:Append"=$true;
    "Out-File:FilePath"=$output
}

This feature is especially useful when you must specify the same alternate parameter value nearly every time you use the command or when a particular parameter value is difficult to remember, such as an email server name or project GUID.

js2010 · Answer 3 · 2022-05-24T14:16:13.753

0

Or put everything inside a function or scriptblock. Note that out-file defaults to utf16 encoding, and can mix encodings, as opposed to add-content.

& {
  ... collect OS information ... 
  ... collect local users ... 
  ... collect logfile permissions ... 
} | add-content $output

edited May 24 '22 at 14:16

answered May 24 '22 at 13:59

js2010

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Powershell - avoid repeating arguments of Out-File

3 Answers3