How to do it...

Install and start PowerShell Core and execute the following steps:

1. Try the following cmdlets and observe the result:

# This command will return both an error and one output object
Get-Item -Path $home,'doesnotexist'

# This command usually returns nothing. The Verbose parameter however enables another stream.
Remove-Item -Path $(New-TemporaryFile) -Verbose

1. The Verbose parameter was actually part of the common parameters. Run the next lines of code and observe what happens now:

Get-Item -Path $home,'doesnotexist' -ErrorAction SilentlyContinue -OutVariable file -ErrorVariable itemError
$file.FullName # Yes, it's your file
$itemError.Exception.GetType().FullName # This sure looks like your error

1. Like the Verbose and Debug streams, the information stream isn't visible by default. Try executing the following code to see the versatility of the information stream:

function Get-AllTheInfo
{
    [CmdletBinding()]param()

    Write-Information -MessageData $(Get-Date) -Tags Dev,CIPipelineBuild
    if ($(Get-Date).DayOfWeek -notin 'Saturday','Sunday')
    {
        Write-Information -MessageData "Get to work, you slacker!" -Tags Encouragement,Automation
    }
}

# Like the Verbose and Debug streams, Information isn't visible by default
# Working with the information is much improved by cmdlets that actually process the tags
Get-AllTheInfo -InformationVariable infos
Get-AllTheInfo -InformationAction Continue

# Information can be filtered and processed, allowing more sophisticated messages in your scripts
$infos | Where-Object -Property Tags -contains 'CIPipelineBuild'

1. Streams can also be controlled globally through the Preference variables as the next sample shows:

$ErrorActionPreference = 'SilentlyContinue'
$VerbosePreference = 'Continue'
Import-Module -Name Microsoft.PowerShell.Management -Force
Get-Item -Path '/somewhere/over/the/rainbow'

1. Additional parameters exist for the purpose of risk mitigation. You might already know them as WhatIf and Confirm. Take a look at the following example:

Remove-Item -Path (New-TemporaryFile) -Confirm
Remove-Item -Path (New-TemporaryFile) -WhatIf

# WhatIf and Confirm are governed by automatic variables as well
$WhatIfPreference = $true
New-TemporaryFile

$WhatIfPreference = $false # Reset to default
$ConfirmPreference = 'Low' # None,Low,Medium,High
New-TemporaryFile

1. As a cmdlet developer, try to use the Write cmdlets (apart from Write-Host) to write to different streams:

Write-Warning -Message 'A warning looks like this'
Write-Error -Message 'While an error looks like this'
Write-Verbose -Message 'Verbose, Debug and Information are hidden by default'