Question

How to get POST variable using regex like this:

$var = $_POST['foo?'];

or

$var = $_POST['foo\w{1}'];

Edit:

My form has many buttons with separate names: file1, file2, file3. When pressing a button, of course it pass file1 or file2, … I want to get the value using that name.

Answer 1

The easiest thing I can think of is this:

$allPostKeys = implode(',',array_keys($_POST));
$wildcardVals = array();
if (preg_match_all('/,?(foo[0-9]),?/',$allPostKeys,$matches))
{
    $wildCardKeys = $matches[1];
    while($key = array_shift($wildCardKeys))
    {
        $wildcardVals[$key] = $_POST[$key];
    }
}
if (!empty($wildcardVals))
{//do stuff with all $_POST vals that you needed
}

Replace [0-9] in the regex with . to match any char, or whatever you need to see matched.
Tested this out with an array that had the following keys bar,zar,foo1,foo2,foo3, and it returned array('foo1' => 'val1','foo2' => 'val2','foo3' => 'val3'), which is what you need, I think.

In response to your edit
The $_POST super-global can be a multi dimensional array, too:

<input type="file" name="file[]" id="file1"/>
<input type="file" name="file[]" id="file2"/>
<input type="file" name="file[]" id="file3"/>

That way, you can easily loop through the files:

foreach($_POST['file'] as $file)
{
    //process each file individually: $file is the value
}