Two PHP functions, match_pattern and match_pattern_all that compare a numeric string against an Asterisk dial pattern (or array of patterns) and return a modified numeric string.

match_pattern.php

<?PHP
// Written by jkiel
// license: GNU/GPL2 or later


/*
  Match a phone number against an array of patterns
  return array containing
  'pattern' = the pattern that matched
  'number' = the number that matched, after applying rules
  'status' = true if a valid array was supplied, false if not

 */
function match_pattern_all($array, $number) {

	// If we did not get an array, it's probably a list. Convert it to an array.
	if (!is_array($array)) {
		$array = explode("\n", trim($array));
	}

	$match = false;
	$pattern = false;

	// Search for a match
	foreach ($array as $pattern) {
		// Strip off any leading underscore
		$pattern = (substr($pattern, 0, 1) == "_") ? trim(substr($pattern, 1)) : trim($pattern);
		if ($match = match_pattern($pattern, $number)) {
			break;
		} elseif ($pattern == $number) {
			$match = $number;
			break;
		}
	}

	// Return an array with our results
	return array(
		'pattern' => $pattern,
		'number' => $match,
		'status' => (isset($array[0]) && (strlen($array[0]) > 0))
	);
}

/**
  Parses Asterisk dial patterns and produces a resulting number if the match is successful or false if there is no match.
 */
function match_pattern($pattern, $number) {
	$pattern = trim($pattern);
	$p_array = str_split($pattern);
	$tmp = "";
	$expression = "";
	$new_number = false;
	$remove = NULL;
	$insert = "";
	$error = false;
	$wildcard = false;
	$match = $pattern ? true : false;
	$regx_num = "/^\[[0-9]+(\-*[0-9])[0-9]*\]/i";
	$regx_alp = "/^\[[a-z]+(\-*[a-z])[a-z]*\]/i";

	// Try to build a Regular Expression from the dial pattern
	$i = 0;
	while (($i < strlen($pattern)) && (!$error) && ($pattern)) {
		switch (strtolower($p_array[$i])) {
			case 'x':
				// Match any number between 0 and 9
				$expression .= $tmp . "[0-9]";
				$tmp = "";
				break;
			case 'z':
				// Match any number between 1 and 9
				$expression .= $tmp . "[1-9]";
				$tmp = "";
				break;
			case 'n':
				// Match any number between 2 and 9
				$expression .= $tmp . "[2-9]";
				$tmp = "";
				break;
			case '[':
				// Find out if what's between the brackets is a valid expression.
				// If so, add it to the regular expression.
				if (preg_match($regx_num, substr($pattern, $i), $matches)
						|| preg_match($regx_alp, substr(strtolower($pattern), $i), $matches)) {
					$expression .= $tmp . "" . $matches[0];
					$i = $i + (strlen($matches[0]) - 1);
					$tmp = "";
				} else {
					$error = "Invalid character class";
				}
				break;
			case '.':
				// Match one or more occurrences of any number
				if(!$wildcard){
					$wildcard = true;
					$expression .= $tmp."[0-9]+";
					$tmp = "";
				}else{
					$error = "Cannot have more than one wildcard";
				}
			break;
			case '!':
				// zero or more occurrences of any number
				if (!$wildcard) {
					$wildcard = true;
					$expression .= $tmp . "[0-9]*";
					$tmp = "";
				} else {
					$error = "Cannot have more than one wildcard";
				}
				break;
			case '+':
				// Prepend any numbers before the '+' to the final match
				// Store the numbers that will be prepended for later use
				if (!$wildcard) {
					if ($insert) {
						$error = "Cannot have more than one '+'";
					} elseif ($expression) {
						$error = "Cannot use '+' after X,Z,N or []'s";
					} else {
						$insert = $tmp;
						$tmp = "";
					}
				} else {
					$error = "Cannot have '+' after wildcard";
				}
				break;
			case '|':
				// Any numbers/expression before the '|' will be stripped

				if (!$wildcard) {
					if ($remove) {
						$error = "Cannot have more than one '|'";
					} else {
						// Move any existing expression to the "remove" expression
						$remove = $tmp . "" . $expression;
						$tmp = "";
						$expression = "";
					}
				} else {
					$error = "Cannot have '|' after wildcard";
				}
				break;
			default:
				// If it's not any of the above, is it a number betwen 0 and 9?
				// If so, store in a temp buffer.  Depending on what comes next
				// we may use in in an expression, or a prefix, or a removal expression
				if (preg_match("/[0-9]/i", strtoupper($p_array[$i]))) {
					$tmp .= strtoupper($p_array[$i]);
				} else {
					$error = "Invalid character '" . $p_array[$i] . "' in pattern";
				}
		}
		$i++;
	}
	$expression .= $tmp;
	$tmp = "";
	if ($error) {
		// If we had any error, report them
		$match = false;
	} else {
		// Else try out the regular expressions we built
		if (isset($remove)) {
			// If we had a removal expression, se if it works
			if (preg_match("/^" . $remove . "/i", $number, $matches)) {
				$number = substr($number, strlen($matches[0]));
			} else {
				$match = false;
			}
		}
		// Check the expression for the rest of the number
		if (preg_match("/^" . $expression . "$/i", $number, $matches)) {
			$new_number = $matches[0];
		} else {
			$match = false;
		}
		// If there was a prefix defined, add it.
		$new_number = $insert . "" . $new_number;
	}
	if (!$match) {
		// If our match failed, return false
		$new_number = false;
	}
	return $new_number;
}