Automatically assign command output to a variable in Powershell

Question

Is there a hack to encapsulate all commands in a Powershell session so that all output is tee'd to a temporary variable?

My problem arises when I enter a command Some-Function

I'm fully aware of commands like Tee-Object and -OutVariable that allow me to pipe a function's output to a variable as well as to the console. I could accomplish my goal with the following:

Some-Function | Tee-Object -Variable PSMyCustomTempVariable

However, I often don't know or anticipate whether I need the variable until after I've run already run Some-Function. In this case, it'd be great to have a variable standing by that contains the output from the last function. This is especially helpful for functions that take a while to run like recursive file searches.

I've looked at about_Logging as well as Start-Transcript, but these seem to be concerned with recording text to a file; I need the objects returned by the function.

So, is there any way to modify my session so that any Powershell command Some-Function basically turns into Some-Function | Tee-Object -Variable PSMyCustomTempVariable?

Solution

Not exactly. However,

$Variable = (Some-Function)

will save the output of Some-Function in the variable $Variable, and allow you to then manipulate the data or pass it to other functions later on. To accomplish the equivalent of

Some-Function | Tee-Object -Variable $Variable

which would take the output of Some-Function, save it in $variable, and pass it through the pipe to the next command, you could use

$variable = (Some-Function)
$variable

(or $variable | Next-Command), and accomplish what you appear to want.

Comments

[Stadem]

Thanks Jeff; this is what I usually end up doing though. I'm looking for something that will assign the variable for me. Maybe a PSReadlineKeyHandler option, I'll check that out.

[Jeff Zeitlin]

I'm not sure what you mean by 'assign the variable for me'. What, specifically, is inadequate or unacceptable about this, which is the defined and standard way of doing what you want in PowerShell?

[Stadem]

I'm looking for a hack, not a standard method. The standard method requires a lot of extra typing for a variable I may not need. I'll try to modify the question accordingly.

[Jeff Zeitlin]

I don't see "a lot" of extra typing, but I also find that ($variable = (some-command)) | Next-Command works as well. Point-blank, you are not going to get a 'tee' for this. PowerShell doesn't support it, unless you are going to write your own cmdlet from scratch.

[Stadem]

OK fair enough :)