filter_input

(PHP 5 >= 5.2.0, PHP 7, PHP 8)

filter_input — Gets a specific external variable by name and optionally filters it

Description

filter_input(
    int $type,
    string $var_name,
    int $filter = FILTER_DEFAULT,
    array|int $options = 0
): mixed

Parameters

type
One of the INPUT_* constants.
Warning

The content of the superglobal that is being filtered is the original "raw" content provided by the SAPI, prior to any user modification to the superglobal. To filter a modified superglobal use filter_var() instead.

var_name
Name of a variable to filter inside the corresponding type superglobal.
filter
The filter to apply. Can be a validation filter by using one of the FILTER_VALIDATE_* constants, a sanitization filter by using one of the FILTER_SANITIZE_* or FILTER_UNSAFE_RAW, or a custom filter by using FILTER_CALLBACK.

Note: The default is FILTER_DEFAULT, which is an alias of FILTER_UNSAFE_RAW. This will result in no filtering taking place by default.

options
Either an associative array of options, or a bitmask of filter flag constants FILTER_FLAG_*. If the filter accepts options, flags can be provided by using the "flags" field of array.

Return Values

On success returns the filtered variable. If the variable is not set false is returned. On failure false is returned, unless the FILTER_NULL_ON_FAILURE flag is used, in which case null is returned.

Examples

Example #1 A filter_input() example

<?php
$search_html = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_SPECIAL_CHARS);
$search_url = filter_input(INPUT_GET, 'search', FILTER_SANITIZE_ENCODED);
echo "You have searched for $search_html.\n";
echo "<a href='?search=$search_url'>Search again.</a>";
?>

The above example will output something similar to:

You have searched for Me &#38; son.
<a href='?search=Me%20%26%20son'>Search again.</a>

See Also