Extract text from every three lines using Windows

Question

I have a HUGE text file with details of my site users. (11GB+). It's built like that:

Email: [e-mail]
Address: 1blahblahblahblah (Bitcoin Address).
Password: blahblahblah

Each of the details in a seperate line. (no spaces between them).

The detail I need is the Bitcoin address. I need them orginized in a text file, one after another.

Simply, I need a batch/java/whatever script that skips the first line, takes the Bitcoin address and puts it in a file, and then skips another line.. continuously.

I need the exported BTC addresses in a list, one address for each line.

The output I need:

1Exampleexampleexample

1Exampleexampleexample

1Exampleexampleexample

1Exampleexampleexample

Thanks in advance guys.

Answer 1

Here's a PowerShell script that will fetch every 2nd line (in groups of 3) and remove the superfluous text and the beginning and end of that line:

$fileToProcess = "C:\users\jsmith\Dropbox\neat scripts\userInfo.txt"
$fileToWrite = "C:\users\jsmith\Dropbox\neat scripts\bitcoin.txt" 
$reader = [System.IO.File]::OpenText($fileToProcess)
$lineCount = 1
try {
        for(;;) {                
            $line = $reader.ReadLine()
            if ($line -eq $null) { break }
            # process the line
            if ($lineCount -eq 2) {  
                $line = $line -replace "Address: "
                $line = $line -replace ' \(Bitcoin Address\).'
                Add-Content $fileToWrite ("`n"+$line)    
            }

            $lineCount = $lineCount+1
            if ($lineCount -gt 3) { $lineCount = 1}
        }
    }
    finally {
        $reader.Close()
    }

Per my normal caveat, do not test this without making a backup of the file you're parsing. I have tested this on my machine (with a much smaller file than the one you're parsing) and it shouldn't change the input file, however, your mileage may vary!

Answer 2

How do I extract text from every third line?

The detail I need is the Bitcoin address. I need them orginized in a text file, one after another.

You can use findstr.

Note:

• I don't have an 11GB file to test against.

Test data:

Email: [e-mail]
Address: address 1 (Bitcoin Address).
Password: blahblahblah
Email: [e-mail]
Address: address 2 (Bitcoin Address).
Password: blahblahblah
Email: [e-mail]
Address: address 3 (Bitcoin Address).
Password: blahblahblah

Command:

findstr Address data.txt > address.out

Output:

C:\test>type address.out
Address: address 1 (Bitcoin Address).
Address: address 2 (Bitcoin Address).
Address: address 3 (Bitcoin Address).

---

Further Reading

• An A-Z Index of the Windows CMD command line - An excellent reference for all things Windows cmd line related.
• findstr - Search for strings in files.

Answer 3

FINDSTR - Search for strings in files.

findstr /I /C:"Address:" "HUGE text file.txt">"BTC addresses"

Next resource (required reading) (>, >> etc. special page) Redirection