fseek() by line, not bytes?

php file fgets
jasonbar picture jasonbar · Aug 28, 2010 · Viewed 18.4k times · Source

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

salathe picture salathe · Sep 30, 2011

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).

Related questions

Read file lines backwards (fgets) with php

I have a txt file that I want to read backwards, currently I'm using this: $fh = fopen('myfile.txt','r'); while ($line = fgets($fh)) { echo $line."<br />"; } This outputs all the lines in my file. I want to …

Read More
file_get_contents with empty file not working PHP

I try to use file_get_contents form PHP but it's not working. There is my code : $filename = "/opt/gemel/test.txt"; if($filecontent = file_get_contents($filename)){ $nom = fgets(STDIN); file_put_contents($filename, $nom, FILE_APPEND); } else echo "…

Read More
How to force file download with PHP

I want to require a file to be downloaded upon the user visiting a web page with PHP. I think it has something to do with file_get_contents, but am not sure how to execute it. $url = "http://example.…

Read More