Increase performance for checking file delimiters - performance

Question

After spending some time looking for the most clearcut way to check if the body of a file has the same amount of delimiters as the header I came up with this code:
Param #user enters the directory path and delimiter they are checking for
(
[string]$source,
[string]$delim
)
#try {
$lineNum = 1
$thisOK = 0
$badLine = 0
$noDelim = 0
$archive = ("*archive*","*Archive*","*ARCHIVE*");
foreach ($files in Get-ChildItem $source -Exclude $archive) #folder directory may have sub folders, as a temp workaround just made sure to exclude any folder with archive
{
$read2 = New-Object System.IO.StreamReader($files.FullName)
$DataLine = (Get-Content $files.FullName)[0]
$validCount = ([char[]]$DataLine -eq $delim).count #count of delimeters in the header
$lineNum = 1 #used to write to host which line is bad in file
$thisOK = 0 #used for if condition to let the host know that the file has delimeters that line up with header
$badLine = 0 #used so the write-host doesnt meet the if condition and write the file is ok after throwing an error
while (!$read2.EndOfStream)
{
$line = $read2.ReadLine()
$total = $line.Split($delim).Length - 1;
if ($total -eq $validCount)
{
$thisOK = 1
}
elseif ($total -ne $validCount)
{
Write-Output "Error on line $lineNum for file $files. Line number $lineNum has $total delimeters and the header has $validCount"
$thisOK = 0
$badLine = 1
break; #break or else it will repeat each line that is bad
}
$lineNum++
}
if ($thisOK = 1 -and $badLine -eq 0 -and $validCount -ne 0)
{
Write-Output "$files is ok"
}
if ($validCount -eq 0)
{
Write-Output "$files does not contain entered delimeter: $delim"
}
$read2.Close()
$read2.Dispose()
} #end foreach loop
#} catch {
# $ErrorMessage = $_.Exception.Message
# $FailedItem = $_.Exception.ItemName
#}
It works for what I have tested so far. However, when it comes to larger files, it takes considerably longer. I was wondering what I can do or change for this code to make it process these text/CSV files more quickly?
Also, my try..catch statements are commented out since the script doesn't seem to run when I include them - no error just enters a new command line. As a thought I was looking to incorporate a simple GUI for other users to double check.
Sample file:
HeaderA|HeaderB|HeaderC|HeaderD //header line
DataLnA|DataLnBBDataLnC|DataLnD|DataLnE //bad line
DataLnA|DataLnB|DataLnC|DataLnD| //bad line
DataLnA|DataLnB|DataLnC|DataLnD //good line
Now that I look at it, I guess there could be an issue where there are the correct amount if delimeters but the columns mismatch like this:
HeaderA|HeaderB|HeaderC|HeaderD
DataLnA|DataLnBDataLnC|DataLnD|

Answer 1

The main problem that I see is that you are reading the file twice -- once with the call to Get-Content, which reads the entire file into memory, and a second time with your while loop. You can double the speed of your process by replacing this line:
$DataLine = (Get-Content $files.FullName)[0] #inefficient
with this:
$DataLine = Get-Content $files.FullName -First 1 #efficient