Count records in csv file - Powershell - powershell

Question

I have following PS script to get a count. Is there a way to count (minus the header) without importing the entire csv? Sometimes the csv file is very large and sometime it has no records.
Get-ChildItem 'C:\Temp\*.csv' | ForEach {
$check = Import-Csv $_
If ($check) { Write-Host "$($_.FullName) contains data" }
Else { Write-Host "$($_.FullName) does not contain data" }
}

Answer 1

To count the rows without worrying about the header use this:
$c = (Import-Csv $_.FullName).count
However this has to read the entire file into memory. A faster way to count the file would be to use the Get-Content with the readcount flag like so:
$c = 0
Get-Content $_.FullName -ReadCount 1000 | % {$c += $_.Length}
$c -= 1
To remove the header row from the count you just subtract 1. If your files with no rows don't have an header you can avoid them counting as minus 1 like so:
$c = 0
Get-Content $_.FullName -ReadCount 1000 | % {$c += $_.Length}
$c -= #{$true = 0; $false = - 1}[$c -eq 0]

Answer 2

Here is the function that will check is CSV file empty (returns True if empty, False otherwise) with following features:
Can skip headers
Works in PS 2.0 (PS 2.0 hasn't -ReadCount switch for Get-Content cmdlet)
Doesn't load entire file in memory
Aware of CSV file structure (wouldn't count empty/nonvalid lines).
It accepts following arguments:
FileName: Path to CSV file.
MaxLine: Maximum lines to read from file.
NoHeader: If this switch is not specified, function will skip first line of the file
Usage example:
Test-IsCsvEmpty -FileName 'c:\foo.csv' -MaxLines 2 -NoHeader
function Test-IsCsvEmpty
{
Param
(
[Parameter(Mandatory = $true, ValueFromPipeline = $true, ValueFromPipelineByPropertyName = $true)]
[string]$FileName,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[ValidateRange(1, [int]::MaxValue)]
[int]$MaxLines = 2,
[Parameter(ValueFromPipelineByPropertyName = $true)]
[switch]$NoHeader
)
Begin
{
# Setup regex for CSV parsing
$DQuotes = '"'
$Separator = ','
# http://stackoverflow.com/questions/15927291/how-to-split-a-string-by-comma-ignoring-comma-in-double-quotes
$SplitRegex = "$Separator(?=(?:[^$DQuotes]|$DQuotes[^$DQuotes]*$DQuotes)*$)"
}
Process
{
# Open file in StreamReader
$InFile = New-Object -TypeName System.IO.StreamReader -ArgumentList $FileName -ErrorAction Stop
# Set inital values for Raw\Data lines count
$CsvRawLinesCount = 0
$CsvDataLinesCount = 0
# Loop over lines in file
while(($line = $InFile.ReadLine()) -ne $null)
{
# Increase Raw line counter
$CsvRawLinesCount++
# Skip header, if requested
if(!$NoHeader -and ($CsvRawLinesCount -eq 1))
{
continue
}
# Stop processing if MaxLines limit is reached
if($CsvRawLinesCount -gt $MaxLines)
{
break
}
# Try to parse line as CSV
if($line -match $SplitRegex)
{
# If success, increase CSV Data line counter
$CsvDataLinesCount++
}
}
}
End
{
# Close file, dispose StreamReader
$InFile.Close()
$InFile.Dispose()
# Write result to the pipeline
if($CsvDataLinesCount -gt 0)
{
$false
}
else
{
$true
}
}
}