Hi John FENDER. It seems like you might have given up too early, before the cavalry arrived. See Re^2: How to optimize a regex on a large file read line by line ?. Looks like both are even faster than the grep+wc solution, though this would need to be confirmed on your machine.

Hi ! You have all my code and my number, i can't give more ! On My machine, Grep+Wc are the faster. And the line by line solution are also faster than puttin all the lines in memory, then searching. Cheers.

marioroy has found that the bigbuffer method (found in http://ideone.com/LzaQI0) runs in 7.8 seconds on his machine, vs the 10.71 seconds you get for grep+wc. What's not known is the relative speed of the two machines. Unfortunately, my machines are in storage while I'm moving, and I'm stuck on this tiny tablet, so I can't run any benchmarks myself. So I ask again, please, can you adopt and run the above code on your machine so we can get accurate results for both the above bigbuffer technique and grep+wc?

Alone our grep vs perl discussion showed that you are comparing apples with oranges.

The only thing you are possibly benchmarking are your coding skills.

It was not the place neither the object of my post, but why not. Not sure it will interest anyone here, but here it is :

C++

    int counter=0;
    int counter2=0;
    regex MyRegex("123456$");
    string ligne;
    ifstream file("10-million-combos.txt" ); 
    if (file.is_open())
    { 
        while (getline(file,line))
        {
            ++counter;
            if(regex_search(line,MyRegex)) {
                ++counter2;
            }
        }
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Pascal/Delphi

  RegexObj := TRegExpr.Create;
  RegexObj.Expression := '123456$';
   reset(tfIn);
    while not eof(tfIn) do
    begin
      readln(tfIn, s);
      if RegexObj.Exec(s) then counter2:=counter2+1;
      counter:=counter+1;
    end;
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PS

    $f = [System.IO.File]::OpenText("10-million-combos.txt")
    while (! $f.EndOfStream) {
        $line = $f.ReadLine();
        if ($line -match "123456$" ) { $counter +=1 }
        $counter2+=1
    }
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Py

    with open("10-million-combos.txt", encoding="cp850") as infile:
        for line in infile:
            counter2 += 1
            if re.search('123456$', line):
                counter += 1
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Rb (not give he right numbers)

    open("10-million-combos_LF.txt") do |content|
        content.each_line do |line|
            counter=counter+1
            if line.match(/123456$/) 
                counter2 += 1
            end
        end
    end
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VB.net

    Dim mStreamReader As StreamReader = New StreamReader("10-million-c
+ombos.txt")
    line = mStreamReader.ReadLine()
    Do While (line IsNot Nothing)
        counter += 1
        If Regex.IsMatch(line, "123456$") Then counter2 += 1
        line = mStreamReader.ReadLine()
    Loop
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VBS

    Set objTextFile = objFSO.OpenTextFile("10-million-combos.txt", For
+Reading)
    Set objRegEx = CreateObject("VBScript.RegExp")
    objRegEx.Pattern = "123456$"
    Count=0
    Count2=0
    Do Until objTextFile.AtEndOfStream 
        Count2=Count2+1
        strNextLine = objTextFile.ReadLine
        Set colMatches = objRegEx.Execute(strNextLine)
        Count=Count+colMatches.Count
    Loop
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C#

    Regex rgx = new Regex("123456$");
    int counter = 0;
    int counter2 = 0;
    using (StreamReader sr = new StreamReader(@"10-million-combos.txt"
+))
    {
        String line;
        while ((line = sr.ReadLine()) != null)
        {
            ++counter;
            if (rgx.IsMatch(line))
            {
                ++counter2;
            }
        }
    }
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PHP

    $counter=0;
    $counter2=0;
    $handle = fopen("10-million-combos.txt", "r");
    while (($line = fgets($handle)) !== false) {
        ++$counter;
        if(preg_match('/123456\R$/',$line))
        {
            ++$counter2;
        }
    }
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Java

    String line;
    Pattern p = Pattern.compile("123456$");
    String fichier ="10-million-combos.txt";
    InputStream ips=new FileInputStream(file); 
    InputStreamReader ipsr=new InputStreamReader(ips);
    BufferedReader br=new BufferedReader(ipsr);
    while ((line=br.readLine())!=null){
        m = p.matcher(line);
        if (m.find()) {count2+=1;}
        count+=1;
    }
[download]