How to Count Lines in Large Text Files Efficiently in PHP?

Counting Text File Lines Efficiently for Large Files

Problem:

PHP scripts can encounter memory issues when attempting to count the lines of large text files (2MB ). A common approach using file() and count() may trigger a fatal memory error.

Solution:

To avoid memory exhaustion, consider adopting a more efficient approach:

<code class="php">$file = "largefile.txt";
$linecount = 0;
$handle = fopen($file, "r");

while (!feof($handle)) {
  $line = fgets($handle);
  $linecount++;
}

fclose($handle);

echo $linecount;</code>

This approach uses fgets() to read a single line at a time, which reduces memory usage.

For extremely long lines, a variation using substr_count() can be used to count end-of-line characters:

<code class="php">$handle = fopen($file, "r");

while (!feof($handle)) {
  $line = fgets($handle, 4096);
  $linecount = $linecount + substr_count($line, PHP_EOL);
}

fclose($handle);

echo $linecount;</code>

By implementing these techniques, PHP scripts can efficiently count the lines of large text files while conserving memory.

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