StringToBrainfuck.php

<?php
/**
 * StringToBrainfuck.php
 *
 * Converts a string to a Brainfuck script that will output said string.
 * usage: php StringToBrainfuck.php your string here
 *
 * @author Maxamilian Demian <max@maxdemian.com>
 * @link https://www.maxodev.org
 * @link https://github.com/Maxoplata/StringToBrainfuck
 */

// if we have arguments passed to the script
if (count($argv) > 1) {
	$inputString = implode(' ', array_splice($argv, 1));

	// the Brainfuck code we will output in the end
	$bfCode = '';

	/**
	 * our current location on the "tape" (pointer 1).
	 * we use pointer 0 as a multiplier for pointer 1 to shorten the output script.
	 *
	 * e.g.
	 * A(65) = ++++++[>++++++++++<-]>+++++.
	 * ++++++      = add 6 to current pointer value (pointer 0)
	 * [           = while current pointer (pointer 0)'s value > 0
	 * >           = move pointer ahead one (to pointer 1)
	 * ++++++++++  = add 10 to current pointer value (pointer 1)
	 * <           = move pointer back one (to pointer 0)
	 * -           = subtract 1 from current pointervalue (pointer 0)
	 * ]           = end while loop
	 * >           = move pointer ahead one (to pointer 1)
	 * +++++       = add 5 to current pointer value (pointer 1)
	 * .           = print out character at current pointer value (pointer 1, value 65, char 'A')
	 *
	 * instead of:
	 * +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
	 */
	$currentLocation = 0;

	// iterate through each character in the string
	for ($i = 0; $i < strlen($inputString); $i++) {
		// get the Unicode code for the current character
		$charVal = ord($inputString[$i]);

		if ($charVal > $currentLocation) {
			// move ahead on the "tape" to build the character
			$bfCode .= str_repeat('+', floor(($charVal - $currentLocation) / 10));
			$bfCode .= '[>++++++++++<-]>';
			$bfCode .= str_repeat('+', ($charVal - $currentLocation) % 10);
		} elseif ($charVal < $currentLocation) {
			// move backwards on the "tape" to build the character
			$bfCode .= str_repeat('+', floor(($currentLocation - $charVal) / 10));
			$bfCode .= '[>----------<-]>';
			$bfCode .= str_repeat('-', ($currentLocation - $charVal) % 10);
		} else {
			// delete the "<" from the previous command as we are on the same character
			// and we will want to print it out again
			$bfCode = substr($bfCode, 0, -1);
		}

		// print out the current character
		$bfCode .= '.';

		// if we are not on the last letter of the string, move pointer position back to 0
		if ($i < (strlen($inputString) - 1)) {
			$bfCode .= '<';
		}

		$currentLocation = $charVal;
	}

	print $bfCode . PHP_EOL;
}