Undefined constant ENT_SUBSTITUTE

PHP
1 
<?php
if (isset($_GET['key'])) {
$key=$_GET['key'];
} else {
$key='';
}

$key=str_replace('\\', '', htmlspecialchars($key, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8') );

$html='<a href="t08.php">initial</a><br>
<form method="get">  
    <input name="key" value="' .$key. '">
    <button type="submit">Search</button> 
</form>';
echo $html;

I have the code above at http://form.kr/test01/t1/t08.php?key="
It works fine…

I add error_reporting at the code above like the code below.at http://form.kr/test01/t1/t09.php?key="

<?php
declare(strict_types=1);
error_reporting(-1);
ini_set('display_errors', '1');

if (isset($_GET['key'])) {
$key=$_GET['key'];
} else {
$key='';
}

$key=str_replace('\\', '', htmlspecialchars($key, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8') );

$html='<a href="t08.php">initial</a><br>
<form method="get">  
    <input name="key" value="' .$key. '">
    <button type="submit">Search</button> 
</form>';
echo $html;

The code above which has error_reporting says like the quote below.

How can I define the “constant” for removeing the error?

2

you can define() constants

https://www.php.net/manual/en/function.define.php

3

What version of PHP are you using?

(I just wondered why the constant would not already be defined as the documentation suggests it was added in 5.4.0, in March 2012.)

1 Like
4

I am afraid it is under 5.4…

5

I tried to add “define(“CONSTANT”, “ENT_SUBSTITUTE”);”.

<?php

declare(strict_types=1);
error_reporting(-1);
ini_set('display_errors', '1');

if (isset($_GET['key'])) {
$key=$_GET['key'];

} else {
$key='';
}

define("CONSTANT", "ENT_SUBSTITUTE");

$key=str_replace('\\', '', htmlspecialchars($key, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8') );

$html='<a href="t08.php">initial</a><br>
<form method="get">  
    <input name="key" value="' .$key. '">
    <button type="submit">Search</button> 
</form>';

echo $html;

The code above at http://form.kr/test01/t1/t10.php still produces the quote below.

What other trials should I try?

6

You could try reading the link that @chorn sent you, that has samples of how to define a constant :slight_smile:

But what value will you give it? I would suggest you set it to zero so it doesn’t upset anything, and make sure your definition is somewhere you can easily find when you upgrade to a newer version. If you’re not intending to upgrade for some reason, then leave it out as it’s not going to do anything.

7

Or if you’re incredibly lazy…
if(phpversion() < "5.4") {

8

As long as you keep messing with obsolete PHP versions that are hundreds and hundreds of releases behind you are just going to keep having problems you shouldn’t be having.

9 
if (!defined('ENT_SUBSTITUTE')) {
    define('ENT_SUBSTITUTE',0); // Real value is 8 but use 0 to be safe
}
echo 'ENT_SUBSTITUTE ' . ENT_SUBSTITUTE . "\n";
10

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