Short tags is a topic of some controversy in coding circles: wrapping your script in less-than, question-mark x 2, greater-than signs is easy to type and flows off the fingers but can be a source of confusion to some parsers. In PHP, it is not recommended, but there is a “shorttag” option available to override it globally or locally.

I recently was asked to edit some older PHP code and found it was littered with short tags, both the <? script goes here ?> variety and the shortcut output <?=”Print this string”?> variety, which need to be replaced by <?php script goes here ?> and <?php echo “Print this string” ?> respectively. A bit beyond my search-and-replace regex or sed skills, I found a fairly elegant solution on StackOverflow, which uses PHP to rewrite PHP:

#! /usr/bin/php
 <?php
 global $argv;

$contents = file_get_contents($argv[1]) or die;
 $tokens = token_get_all($contents);
 $tokens[] = array(0x7E0F7E0F,"",-1);

foreach($tokens as $ix => $token) {
 if(is_array($token)) {
 list($toktype, $src) = $token;
 if ($toktype == T_OPEN_TAG) {
 if (($src == "<?") && ($tokens[$ix+1][0] != T_STRING)) {
 $src = "<?php";
 if ($tokens[$ix+1][0] != T_WHITESPACE) {
 $src .= " ";
 }
 }
 }
 else if($toktype == T_OPEN_TAG_WITH_ECHO) {
 $src = "<?php echo";
 if($tokens[$ix+1][0] != T_WHITESPACE) {
 $src .= " ";
 }
 }
 print $src;
 }
 else {
 print $token;
 }
 }

It just needed a little shell wrapper to take in all the files (which I’d renamed *.php.old and archived and made a backup of) and put them out as *.php.old.new. Again, a quick rename and I was in business. I was astounded to find it ran the first time!

#! /bin/bash

FILES=./*.php.old
 for f in $FILES
 do
 echo "phpize $f >$f.new"
 ./phpize.php $f>$f.new
 done