International PHP Conference 2015

PHP tags

When PHP parses a file, it looks for opening and closing tags, which are <?php and ?> which tell PHP to start and stop interpreting the code between them. Parsing in this manner allows PHP to be embedded in all sorts of different documents, as everything outside of a pair of opening and closing tags is ignored by the PHP parser.

PHP also allows for short open tag <? (which is discouraged since it is only available if enabled using the short_open_tag php.ini configuration file directive, or if PHP was configured with the --enable-short-tags option).

If a file is pure PHP code, it is preferable to omit the PHP closing tag at the end of the file. This prevents accidental whitespace or new lines being added after the PHP closing tag, which may cause unwanted effects because PHP will start output buffering when there is no intention from the programmer to send any output at that point in the script.

<?php
echo "Hello world";

// ... more code

echo "Last statement";

// the script ends here with no PHP closing tag

Changelog
Version Description
7.0.0 The ASP tags <%, %>, <%=, and the script tag <script language="php"> are removed from PHP.
5.4.0 The tag <?= is always available regardless of the short_open_tag ini setting.

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User Contributed Notes 6 notes

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29
purkrt at gmail dot com
5 months ago
I would like to stress out that the opening tag is "<?php[whitespace]", not just "<?php". While this might seem blatantly obvious, I thought for some time that

<?php/*blah*/ echo "a"?>

would work, and it does not; the comment does not work as whitespace. I've run into this while converting some older code with short open tag.
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-27
mario
9 months ago
A few related notes, partly covered elsewhere in the manual:

  → Since PHP 5.4 the inline echo <?= ?> short tags are always
    enabled regardless of the short_open_tag (php.ini) setting.

  → PHP tags are infrequently also referred to as open/close "tokens"
    (as per the tokenizers T_OPEN_TAG / _ECHO, and T_CLOSE_TAG naming).

  → The historic ASP-style <% %> and even more rarely used
    <script language=PHP></script> tags are to be repealed in PHP7.
    http://wiki.php.net/rfc/remove_alternative_php_tags

There also exists a small tool called "phptags tidier" for consistently rewriting PHP short/long tags.  It's suitable to normalize include and template scripts, e.g. employ the always-enabled long <?php ?> tags, and/or relieve whitespace padding before/after PHP tags:

    phptags --long --whitespace --warn  *.php

Instead of reliably fixing the common whitespace/BOM issues around tags, it can also just remove all ?> close tags with `--unclose --tokenizer` as advised afore.
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-1
codehunter at gmx dot net
1 month ago
Hope that there will be implemented a INI-Option for a complete deactivation of necessity closing AND opening PHP-Tags for *pure* PHP scripts.
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-48
alexander dot podgorny at somewhere dot com
10 months ago
One reason to use long tags over short is to avoid confusion with <?xml ?> notation.
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-67
billscloud dot mail at gmail dot com
10 months ago
In your paragraph you need to close your bracket.

<grammernazi>Me</grammarnazi>
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-107
preda dot vlad at yahoo dot com
2 years ago
So here are the valid ways to open PHP tags:

<?php ?> // standard tags
<? ?> // short tags, need short_open_tag enabled in php.ini
<% %> // asp tags, need asp_tags enabled in php.ini
<script language="php"> </script> // case insensitive

PSR-1 coding standards suggest to only use <?php ?> or <?= ?> (echo short tags) - and no other variations, and PSR-2 suggests to not close the tags in PHP only files.
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