The Pipeline

Getting started

Making some students

function Make-Student {
    param(
        [string]$firstname="",
        [string]$lastname="",
        [int]$score=3,
        [int]$day = 1,
        [int]$month = 1,
        [int]$year = 2003

    )
    return New-Object -TypeName psobject -Property @{
    "FirstName"=$firstname;
    "LastName"=$lastname;
    "Score"=$score;
    "Birthday"=(get-date -Minute 0 -Second 0 -Millisecond 0 -Hour 0 -Year $year -Day $day -Month $month)
    }
}

$students = @()
$students += make-student -firstname "Bob"  -lastname "Sinclair" -score 3 -day 1 -month 3
$students += make-student -firstname "Alice"  -lastname "Cooper" -score 8 -day 14 -month 4
$students += make-student -firstname "Frank"  -lastname "Sinatra" -score 7 -day 12 -month 9
$students += make-student -firstname "Oscar"  -lastname "Wilde" -score 7 -day 22 -month 5
$students

Select the name and grade

$students | select firstname, score

Sort By Property

$students | Sort-Object -property LastName
$students | Sort-Object -property Birthday 
$students | Sort-Object -property Score
$students | Sort-Object -property Score -Descending

Filtering students

$students | where-object { $_.score -lt 5}

Measuring

$students | measure-object
$students | measure-object -Average -Property Score

$measured = $students | measure-object -Minimum -Property Score
$measured.minimum

$students | measure-object -minimum -Property Birthday | select minimum

For each object, pipeline style

$students | foreach-object { write-host ("Student : {0,-15} `t Score {1}/5" -f $_.Firstname,($_.score/2)) }

Function made for pipeline

function Evaluate-Student {
    param(
        [Parameter(Mandatory=$True,ValueFromPipeline=$True)]
        $student
    )
    begin {
        write-host "Teacher autobot evaluation"
        write-host "##########################"
    }
    process {
        if($student.score -gt 7) {
            write-host ("Keep up the good work {0}" -f $student.FirstName)
            $student | Add-Member -Name Evaluation -Value "Passed" -Type NoteProperty -Force
        } elseif($student.score -gt 5) {
            write-host ("It's okay but next year, try to put some more effort in it {0}" -f $student.FirstName)
            $student | Add-Member -Name Evaluation -Value "Passed with homework" -Type NoteProperty -Force
        } else {
            write-host ("This result is miserable {0}" -f $student.FirstName)
            $student | Add-Member -Name Evaluation -Value "Failed" -Type NoteProperty -Force
        }
    }
    end {
        write-host "##########################"
        write-host "Teacher autobot end"
    }
}
$students | Evaluate-Student 
Evaluate-student -student $students[0]

Show output as table

$students | format-table

Show output as list

$students | format-list

Kill all notepad!

Get-Process -name notepad | Stop-Process