PHP File Handling Notes

files.php

<?php

/************************************
 * NOTE!!!!
 * This file is meant as notes / examples.
 * The code, as it's current written, will not work
 * and will probably output some errors/notices.
 * Use this file as examples, not as code that's meant to be run.
 ************************************
 */

// Different paths to the same file
$filename = 'princesses.txt';
$filename = '../notes/princesses.txt';
$filename = '/vagrant/notes/princesses.txt';

// Magic constants so we can see where our file/director are
echo __FILE__ . PHP_EOL;
echo __DIR__  . PHP_EOL;

// Boolean, checks if the file exists and can be read by our script
is_readable($filename);

// Get the fize of the file, useful for reading entire file at once
$fileSize = filesize($filename);

// File pointer. Describes:
// 1) Which file
// 2) What we can/can't do with the file (read, write, etc)
// 3) Where we are in the file
$handle = fopen($filename, 'r');

// Check if the file pointer has reached the end of the file
feof($handle);

// Pull back the entire contents of the file as a single string
$princessString = fread($handle, $fileSize);
$princessString = fread($handle, filesize($filename));
// Acoustics Princess\n
// Bee Princess\n
// Bounce House Princess\n
// Breakfast Princess\n
// etc..

// Always close your files when you're done with them!
fclose($handle);

function readBytesATime($filename, $bytes = 100) {
    $contents = '';
    
    if (is_readable($filename)) {
        $handle = fopen($filename, 'r');

        while(!feof($handle)) {
            $contents .= fread($handle, $bytes);
        
            sleep(1);
        }

        fclose($handle);
    }
    
    return $contents;
}

fwrite(STDOUT, readBytesATime($filename));

// Remove extra \n at the end of the file
$princessString = trim($princessString);

// Break our string apart into an array
$princesses = explode(PHP_EOL, $princessString);

// Sort our princesses alphabetically
sort($princesses);

// Other modes for opening files
// Open for write, truncate the file
$handle = fopen('sorted_princesses.txt', 'w');

// Open for write, put pointer at END
$handle = fopen('sorted_princesses.txt', 'a');

// Open for write, put pointer at BEGINNING
$handle = fopen('sorted_princesses.txt', 'c');

// Loop through princesses writing them out with a new line at the end
foreach ($princesses as $princess) {
    fwrite($handle, $princess . PHP_EOL);
}

// Glue the $princesses array together, add a final newline character at the end
fwrite($handle, implode("\n", $princesses) . "\n");

// Pick a random index
$hots = array_rand($princesses);

// Open for appending so we can keep track of our history
$handle = fopen('hots.log', 'a');

// Write to our file, append new data
fwrite($handle, "The Ice King totally has the hots for {$princesses[$hots]}!\n");