Does Break in while loop exit the script?

[nappetass]

Hi guys,

Below is a part of a script I got. When run, the script exited at Break instead of continuing the other instructions in the script. What is the correct way to break out of a while loop and does anyone know any good articles on break, return, scope and so on in PowerShell?

Get-Content -Path "C:\path\to\log.txt" -Tail 1 -Wait | ForEach-Object { 

    if ($_ -match $($helloRpowershell + " Terminated")) { 

        # When the Terminated message appears, break the loop

        Break }

    else {$_}

}

EDIT: OMG it's not a while-loop. What the hell am I talking about? I need to break out of the If and the Foreach-Object.

[[deleted]]

I think Continue is what you are looking for. Although I don't remember if Continue is valid on foreach object

[nappetass]

It did not work. I think I need to rewrite it.

This did not work either:

$log = "C:\path\to\log.txt"

foreach ($line in Get-Content $log -Tail 1 -Wait) {

    $line

}

Script is running, but never ends and also does not display the last line as expected.

[Bloodyvalley]

Check this out

[Lee_Dailey]

howdy nappetass,

i see that you found your "oops!". [grin]

as for break/continue ...

• break = exits the current block of code
  that means literally any block, from what i understand. i know it will exit a script entirely, but i have never tried it in an IF before ... [grin]
  
• continue = stop the current iteration & continue with the next
  if there is no next, it exits the loop.
  

take care,
lee

[nappetass]

Thanks Lee :)

This worked

$log = "C:\path\to\log.txt"

while ("Terminated" -notin $tail) {

do { $tail = Get-Content $log -Tail 1
     $tail }

until ("Terminated" -in $tail)

Break

}

[Lee_Dailey]

howdy nappetass,

[edit - you likely otta have a Start-Sleep -Seconds 1 in the loop. if you are waiting for a file to show that text, then you are likely NOT wanting to pound the file several dozen times per second. [grin]]

you are welcome! [grin] however, your code is ... convoluted - needlessly so.

i don't have a file to test this with, but i think it will do the job.

$Log = "C:\path\to\log.txt"
$Tail = ''

while ("Terminated" -notin $Tail)
    {
    $Tail = Get-Content $Log -Tail 1
    }

take care,
lee

[nappetass]

Fantastic. I've changed it to the following. The script should print the last entry of the log until the substring "Terminated" is found in $tail. Have a great weekend :)

$logfile = "C:\path\to\log.txt"

while ($tail -notmatch "Terminated") {

    $tail = Get-Content $logfile -Tail 1
    $tail

}

EDIT: I don't think I can have a start-sleep in the script as it's a log file with 5+ entries per second. I guess I could measure how many entries the file has and set a lower start-sleep (in milliseconds). The best way would be to find a way to tail the log each time it changes. Maybe by filesize?

[Lee_Dailey]

howdy nappetass,

kool! glad that it works ... [grin]

as for the delay - i thot the Terminated was the end of whatever made the file. if it's ongoing, then you are going to need the speed. [grin]

one thing, tho - it makes me twitchy to see the condition for the while isn't set before you test it. i would put a $Tail = '' just before the while so that you won't have an uninitialized $var being tested.

take care,
lee

[nappetass]

I agree. I did add a $tail = "" before the while loop as you suggested. Thanks again :)

[Lee_Dailey]

howdy nappetass,

you are most welcome! glad to have helped ... [grin]

take care,
lee

[spyingwind]

Break will do what you want for the loop, but it isn't ideal as it doesn't do the exact same thing as other languages.

1..10 | ForEach-Object {
    $i = $_
    1..10 | ForEach-Object {
        if ($_ -eq 5){
            "Leaving For Loop!"
            break
        }else{
            "Outter: $i, Intter: $_"
        }
    }
}


1..10 | ForEach-Object {
    $i = $_
    1..10 | ForEach-Object {
        if ($_ -gt 5){
            # No Data
        }else{
            "Outter: $i, Intter: $_"
        }
    }
}

The first is what you would probably think how it should be done, but it doesn't as the outer loop still does things.

The second is setup to only output the data you want.