Get-Content with Wait and processing each line - powershell

Question

Using -Match gives me True/False values instead of the lines of text.
Get-Content ("\\path”) -tail 10 -wait | % {
foreach ($data in ($_ -match "Execute")) {
$First = $data.Substring(26,37).Trim()
Write-Host $First
}
}
I used below code without -tail -wait to do what I, but I can't change to parsing the file using -tail with Get-Content.
$DB = Get-Content ("\\path”) -tail -ReadCount 5000000 | foreach { $_ -match "string to match" } | foreach{ $_.Trim()}
foreach ($Data in $DB) {
$First = $Data.Substring(26,37).Trim()
$Second = $Data
Write-Host $First
Write-Host $Second
}

Answer 1

As a workaround, you can array-cast your $_, like this:
foreach ($data in (,$_ -match "Execute")) {
Here's the output difference:
$data=#("bla bla","foo bla","foo bar","bla bar")
PS > $data | % { foreach ($a in ($_ -match "bla")){$a}}
True
True
False
True
PS > $data | % { foreach ($a in (,$_ -match "bla")){$a}}
bla bla
foo bla
bla bar

Answer 2

The -match expression returns a boolean result, but also updates a special variable, $matches.
You can filter lines by using -match in a where-object expression to return only those lines which match.
$myFilteredArray = $myArray | where-object{$_ -match 'execute'}
If using it for something that simple though, you may as well use -like:
$myFilteredArray = $myArray | where-object{$_ -like '*execute*'}
If you want to be clever, you can also use regular expressions; that way $matches will hold all captured groups (including a special group named 0 which holds the original line).
Simple Example / plain text search
#(
'line 1 - please '
,'line 2 - execute'
,'line 3 - this'
,'line 4 - script'
) | where-object {$_ -match 'execute'} | foreach-object{
"-Match found the following matches:"
$matches
"The line giving this result was"
$_
}
Example using Regex / capturing group
#(
'line 1 - please '
,'line 2 - execute'
,'line 3 - this'
,'line 4 - script'
) | where-object {$_ -match '(?<capturedData>.*?)(?: - )execute'} | foreach-object{
"-Match found the following matches:"
$matches
"The line giving this result was"
$_
}
-match: https://ss64.com/ps/syntax-regex.html
-like, -match, and other comparisons: https://ss64.com/ps/syntax-compare.html

Answer 3

Well, -match when applied to a scalar returns a boolean result. When applied to an array it returns the matching elements. In your second example you use ReadCount to force Get-Content to send more than a line through the pipeline at a time. Of course you're then getting an array of lines every time instead of just a line, thus changing the semantics of -match.
To make your first example work, simply change foreach into if.