Open php file, change value for one variable, save - php

Question

I am trying to modify the value of a variable $denumire produs=' '; from a php file _inc.config.php through a script by this code with form from file index.php and i have some errors.
The new value of the variable will become value entered from the keyboard via the form.
Anyone can help me, please?
<?php
if (isset($_POST['modify'])) {
$str_continut_post = $_POST['modify'];
if (strlen($_POST['search']) > 0 || 1==1) {
$fisier = "ask003/inc/_inc.config.php";
$fisier = fopen($fisier,"w") or die("Unable to open file!");
while(! feof($fisier)) {
$contents = file_get_contents($fisier);
$contents = str_replace("$denumire_produs =' ';", "$denumire_produs ='$str_continut_post';", $contents);
file_put_contents($fisier, $contents);
echo $contents;
}
fclose($fisier);
die("tests");
}
}
?>
<form method="POST" action="index.php" >
<label>Modifica denumire baza de date: </label>
<input type="text" name="den">
<button type="submit" name="modify"> <center>Modifica</center></button>
</div></div>
</form>

Answer 1

This is an XY problem (http://xyproblem.info/).
Instead of having some sort of system that starts rewriting its own files, why not have the file with the variable you want to change load a json config file?
{
"name": "Bob",
"job": "Tea Boy"
}
Then in the script:
$json = file_get_contents('/path/to/config.json');
$config = json_decode($json, true);
$name = $config['name'];
Changing the values in the config is as simple as encoding an array and putting the json into the file.
$config['denumireProdu'] = 'something';
$json = json_encode($config);
file_put_contents('/path/to/config.json', $json);
This is far saner than getting PHP to rewrite itself!
Docs for those commands:
http://php.net/manual/en/function.json-decode.php
http://php.net/manual/en/function.json-encode.php
http://php.net/manual/en/function.file-get-contents.php
http://php.net/manual/en/function.file-put-contents.php