The `$MyInvocation.ScriptLineNumber` variable is not the Current Line Number. It’s the Line number from where the function that you’re in was called. Actual line numbers can be caught for an error if you catch them. Used in this comment: http://goo.gl/7oeSEL

CatchLineNumbers.ps1

function a {
    param(
        [string]$UninstallString = 'thing'
    )
    $MyInvocation

    Write-Host -Fore Cyan "$($here.File) $($MyInvocation.MyCommand):$($MyInvocation.ScriptLineNumber)"
    b
    try {
        Throw('Thing!!!!')
    } catch {
        Write-Host -Fore Magenta ("{0} {1}:{2}: ErRaWr!! $_" -f @($here.File, $MyInvocation.MyCommand, $_.InvocationInfo.ScriptLineNumber))
    }
}

function b {
    $MyInvocation
    Write-Host -Fore Cyan "$($here.File) $($MyInvocation.MyCommand):$($MyInvocation.ScriptLineNumber)"
}

# Buiding a $this style variable, but $this is an auto variable.
$here = @{
    'File'='Test'
}

Write-Host -Fore Cyan "$($here.File) $($MyInvocation.MyCommand):$($MyInvocation.ScriptLineNumber)"
a
Write-Host -Fore Cyan "$($here.File) $($MyInvocation.MyCommand):$($MyInvocation.ScriptLineNumber)"

Output

Test CatchLineNumbers.ps1:1


MyCommand             : a
BoundParameters       : {}
UnboundArguments      : {}
ScriptLineNumber      : 23
OffsetInLine          : 1
HistoryId             : 137
ScriptName            : C:\Users\ras0196\test.ps1
Line                  : a

PositionMessage       : At C:\Users\ras0196\test.ps1:23 char:1
                        + a
                        + ~
PSScriptRoot          : C:\Users\ras0196
PSCommandPath         : C:\Users\ras0196\test.ps1
InvocationName        : a
PipelineLength        : 1
PipelinePosition      : 1
ExpectingInput        : False
CommandOrigin         : Internal
DisplayScriptPosition :

Test a:23
MyCommand             : b
BoundParameters       : {}
UnboundArguments      : {}
ScriptLineNumber      : 8
OffsetInLine          : 5
HistoryId             : 137
ScriptName            : C:\Users\ras0196\test.ps1
Line                  :     b

PositionMessage       : At C:\Users\ras0196\test.ps1:8 char:5
                        +     b
                        +     ~
PSScriptRoot          : C:\Users\ras0196
PSCommandPath         : C:\Users\ras0196\test.ps1
InvocationName        : b
PipelineLength        : 1
PipelinePosition      : 1
ExpectingInput        : False
CommandOrigin         : Internal
DisplayScriptPosition :

Test b:8
Test a:23
Test CatchLineNumbers.ps1:1