Powershell to remove first 500 characters and last two characters-CodePudding

I have n number of text files in a folder. Each file will have only one line of text in it. I have to remove the first 500 characters and last two characters from each of the file in the folder.

How could this be done using Powershell?

CodePudding user response：

Use the Substring() method to extract a substring from the line:

# Read single line from file
$line = Get-Content file.txt -TotalCount 1

# Extract a substring starting from index 500 until two characters before the end
$truncatedLine = $line.Substring(500, $line.Length - 502)

# Write line back to file
$truncatedLine |Set-Content file.txt -Force

To run against all txt files in a given folder, use Get-ChildItem to discover the files, then process them one-by-one using ForEach-Object:

Get-ChildItem -Path .\path\to\folder -File -Filter *.txt |ForEach-Object {
    $line = $_ |Get-Content -TotalCount 1
    $truncatedLine = $line.Substring(500, $line.Length - 502)
    $truncatedLine |Set-Content -LiteralPath $_.FullName
}

CodePudding user response：

For example, take out the first 5 numbers and last 2. Array indexes start at 0.

$string = '1234567890'
-join $string[5..($string.length-3)]

678