Question

I have a script that parses large files line by line. When it encounters an error that it can’t handle, it stops, notifying us of the last line parsed.

Is this really the best / only way to seek to a specific line in a file? (fseek() is not usable in my case.)

<?php

for ($i = 0; $i < 100000; $i++)
    fgets($fp); // just discard this

I don’t have a problem using this, it is fast enough – it just feels a bit dirty. From what I know about the underlying code, I don’t imagine there is a better way to do this.

Answer 1

An easy way to seek to a specific line in a file is to use the SplFileObject class, which supports seeking to a line number (seek()) or byte offset (fseek()).

$file = new SplFileObject('myfile.txt');
$file->seek(9999);     // Seek to line no. 10,000
echo $file->current(); // Print contents of that line

In the background, seek() just does what your PHP code did (except, in C code).