Reading Very Large Files in PHP

Reading very large files in PHP

Are you sure that it's fopen that's failing and not your script's timeout setting? The default is usually around 30 seconds or so, and if your file is taking longer than that to read in, it may be tripping that up.

Another thing to consider may be the memory limit on your script - reading the file into an array may trip over this, so check your error log for memory warnings.

If neither of the above are your problem, you might look into using fgets to read the file in line-by-line, processing as you go.

$handle = fopen("/tmp/uploadfile.txt", "r") or die("Couldn't get handle");
if ($handle) {
    while (!feof($handle)) {
        $buffer = fgets($handle, 4096);
        // Process buffer here..
    }
    fclose($handle);
}

Edit

PHP doesn't seem to throw an error, it just returns false.

Is the path to $rawfile correct relative to where the script is running? Perhaps try setting an absolute path here for the filename.

Reading huge file line by line in PHP

use fseek, fgets

$handle = fopen("/tmp/uploadfile.txt", "r") or die("Couldn't get handle");
if ($handle) {
    while (!feof($handle)) {
        $line = fgets($handle);
        // Process line here..
    }
    fclose($handle);
}

Reading very large files in PHP

Read and parse contents of very large file

Yes, you can read it line by line:

$handle = @fopen("/tmp/inputfile.txt", "r");
if ($handle) {
    while (($buffer = fgets($handle, 4096)) !== false) {
        echo $buffer;
    }
    fclose($handle);
}

Reading large files from end

It's not pure PHP, but the common solution is to use the tac command which is the revert of cat and loads the file in reverse. Use exec() or passthru() to run it on the server and then read the results. Example usage:

<?php
$myfile = 'myfile.txt';
$command = "tac $myfile > /tmp/myfilereversed.txt";
exec($command);
$currentRow = 0;
$numRows = 20;  // stops after this number of rows
$handle = fopen("/tmp/myfilereversed.txt", "r");
while (!feof($handle) && $currentRow <= $numRows) {
   $currentRow++;
   $buffer = fgets($handle, 4096);
   echo $buffer."<br>";
}
fclose($handle);
?>

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