PHP Tail Library

A PHP Library for tailing files, supporting PHP 7.0 and above.

Currently, this library allows you to get the tail of a given file. Subsequent calls to the getTail function will return whatever has been appended since the last call.

Usage

Firstly let's create some random file with 3 lines of text.

$fileLocation = tempnam(sys_get_temp_dir(), 'tailTest');
file_put_contents($fileLocation, "Hello 1" . PHP_EOL . "Hello 2" . PHP_EOL . "Hello 3" . PHP_EOL);

Now we can instantiate the Tail Config class and inject it into the constructor of the Tail operator, then run the getTail function:

$config = new \IcyApril\Tail\Config($fileLocation);
$config->setLines(2);

$tail = new \IcyApril\Tail\Tail($config);
echo $tail->getTail();

The output of this will be the final two lines of the file we created:

Hello 2
Hello 3

Suppose we then append a line to the file:

file_put_contents($fileLocation, "Hello 4" . PHP_EOL, FILE_APPEND | LOCK_EX);

Running getTail again will yield Hello 4:

echo $tail->getTail();
// Hello 4

When to run getTail?

You can decide when to call the getTail function by either using the inotify watcher or simply using polling with the filemtime() function.

Caveats

• The output is based on line count. If your file has 15 lines to start with, then has 17; the last 2 will be displayed at the next getTail call.
• If a file is over-written and therefore has less than the amount of lines than it started with; the entire new file will be returned at the next getTail call.
• Obviously you need to have your own polling/monitoring to decide when to call getTail