Question

I’m using Windows 2003 Server x86, Powershell 1.0 and have following head-breaking problem. When I’m trying to execute script below, I’m getting an error:

Error "=" operator: System error. (Fehler beim "="-Operator: Systemfehler.)
+ $data =  <<<< Get-Content $log | % {

Here is this script:

$log = "C:\log file.txt"
$linePrefix = "PROCESS THIS LINE"
$trimStart = 25 #chars to ignore in the beginning
$started = 0

$data = Get-Content $log | % { 
    if ($_.length -ge $trimstart) { 
        $linedata = $_.substring($trimstart);
        $timesline = $linedata.startswith($lineprefix); 
        if ($started -eq 0 -and $timesline) { 
            $started = 1; 
        }
        if ($started) { 
            if ($timesline) { 
                $line = $linedata.substring($lineprefix.length).trimstart();
                if ($line.contains(": ")) {
                    write-output $line 
                } 
            } else { 
                break; 
            }
        }
    }
}

However, if I execute it without $data = assignment, it works perfectly and returns me expected values. I’ve also tried following statements

$data = (...)
$data = $(...)

and declaring a function with expression but without success.

Could you please give me a hint why it does happen?

UPDATE: I’ve tried to remove spaces before and after assigment sign and got similar error, but now powershell didn’t like $data=G string

Error "=" operator: System error (Fehler beim "="-Operator: Systemfehler.)
At C:\kosmo\scripts\ps\test.ps1:60 Symbol:7
+ $data=G <<<< et-Content $log | % {

Answer 1

Thanks all to your hints! Pity, but nothing suggested solved my problem indeed.
Most helpful was hint from latkin about break behavior. After some reading I found out, that in Foreach-Object cmdlet, which is aliased by %, break or continue statements stop whole script

function getFilteredResult {

    1..50 | % { 
        if ($_ -le 20) { 
            if (($_ % 2) -eq 0) {
                write-output $_;
            }
        } else {
            break; #terminates whole script, you don't even get "after got result"
            #continue; #save result as break
        }
    }   
}

Write-Host "before getting result"

$result = getFilteredResult

$result | % {$i=0}{ ++$i; Write-Host "$i) $_" }

Write-Host "after got result"

Output shows only before getting result. From there I’ve made a conclusion that there is no way to do what I want in Powershell 1.0! So I found a way to install Powershell 2.0 on my good old 2003 server (tip how to uninstall Powershell 1.0 before; btw, my Windows-update had name KB926140-v5).

Ok, error has gone. But I still have no result I want to have?! At the end of my journey I found very useful post and have written script below

function getFilteredResult {
    Try {
        1..50 | % { 
            if ($_ -le 20) { 
                if (($_ % 2) -eq 0) {
                    write-output $_;
                }
            } else {
                #break; #terminates whole script, you don't even get "after got result"
                #continue; #terminates whole script, you don't even get "after got result"
                throw "terminated pipeline!"
            }
        }   
    } Catch {
        #ignore terminated pipeline exception
    }
}

Write-Host "before getting result"

$result = getFilteredResult

$result | % {$i=0}{ ++$i; Write-Host "$i) $_" }

Write-Host "after got result"

And got an answer:

before getting result
1) 2
2) 4
3) 6
4) 8
5) 10
6) 12
7) 14
8) 16
9) 18
10) 20
after got result

Explanation
If I’d used foreach statement, I could use break with estimated behavior, but I’m working with large log files and foreach-statement reads whole file into memory, while ForEach-Object cmdlet processes lines one by one. I’m not sure about Get-Content cmdlet, maybe it also reads whole file to return it, but I’ve written down my own cmdlet Get-Content-Reversed to read lines from the end of file and that’s why I’m pretty sure it doesn’t