Change pointer for file_put_contents()

Question

$iplog = "$time EST - $userip - $location - $currentpage\n";
file_put_contents("iplog.txt", $iplog, FILE_APPEND);

I am trying to write this to the text file, but it puts it at the bottom and I would prefer if the new entries were at the top. How would I change the pointer for where it puts the text?

possible duplicate of [Need to write at beginning of file with PHP](http://stackoverflow.com/questions/1760525/need-to-write-at-beginning-of-file-with-php) — Clément Malet, Jun 24 '14 at 10:54
[this question](http://stackoverflow.com/questions/3332262/how-do-i-prepend-file-to-beginning) might be useful — lelloman, Jun 24 '14 at 10:54

score 1 · Accepted Answer · answered Jun 24 '14 at 10:54

To prepend at the beginning of a file is very uncommon, as it requires all data of the file copied. If the file is large, this might get unacceptable for performance (especially when it is a log file, which is frequently written to). I would re-think If you really want that.

The simplest way to do this with PHP is something like this:

$iplog = "$time EST - $userip - $location - $currentpage\n";
file_put_contents("iplog.txt", $iplog . file_get_contents('iplog.txt'));

score 0 · Answer 2 · answered Jun 24 '14 at 11:43

The file_get_contents solution doesn't have a flag for prepending content to a file and is not very efficient for big files, which log files usually are. The solution is to use fopen and fclose with a temporary buffer. Then you can have issues if different visitors are updating your log file at the same time, but's that another topic (you then need locking mechanisms or else).

<?php

function prepend($file, $data, $buffsize = 4096)
{
    $handle = fopen($file, 'r+');
    $total_len = filesize($file) + strlen($data);
    $buffsize = max($buffsize, strlen($data));
    // start by adding the new data to the file
    $save= fread($handle, $buffsize);
    rewind($handle);
    fwrite($handle, $data, $buffsize);
    // now add the rest of the file after the new data
    $data = $save;
    while (ftell($handle) < $total_len)
    {
        $chunk = fread($handle, $buffsize);
        fwrite($handle, $data);
        $data = $chunk;
    }
}

prepend("iplog.txt", "$time EST - $userip - $location - $currentpage\n")
?>

That should do it (the code was tested). It requires an initial iplog.txt file though (or filesize throws an error.

Change pointer for file_put_contents()

2 Answers2