Read a file backwards line by line using fseek

Question

How do I read a file backwards line by line using fseek?

code can be helpful. must be cross platform and pure php.

many thanks in advance

regards

Answer 1

The question is asking using fseek, so can only assume that performance is an issue and file() is not the solution. Here is a simple approach using fseek:

My file.txt

#file.txt
Line 1
Line 2
Line 3
Line 4
Line 5

And the code:

Output:

array(5) {
   [0]=>
   string(6) "Line 5"
   [1]=>
   string(6) "Line 4"
   [2]=>
   string(6) "Line 3"
   [3]=>
   string(6) "Line 2"
   [4]=>
   string(6) "Line 1"
}

You don't have to append to the $lines array like I am, you can print the output straight away if that is the purpose of your script. Also it is easy to introduce a counter if you want to limit the number of lines.

$linesToShow = 3;
$counter = 0;
while ($counter <= $linesToShow && -1 !== fseek($fp, $pos, SEEK_END)) {
   // Rest of code from example. After $lines[] = $currentLine; add:
   $counter++;
}