[php] Insert PHP code In WordPress Page and Post

I want to know Visitor country using PHP and display it in to a WordPress Page.But when I add PHP code in WordPress page or Post it give me error. How can we add PHP code in WordPress Page and Post.

  <?PHP
   try{
        function visitor_country()
            {

                $client  = @$_SERVER['HTTP_CLIENT_IP'];
                $forward = @$_SERVER['HTTP_X_FORWARDED_FOR'];
                $remote  = $_SERVER['REMOTE_ADDR'];
                $result  = "Unknown";
                if(filter_var($client, FILTER_VALIDATE_IP))
                {
                    $ip = $client;
                }
                elseif(filter_var($forward, FILTER_VALIDATE_IP))
                {
                    $ip = $forward;
                }
                else
                {
                    $ip = $remote;
                }

                $ip_data = @json_decode(file_get_contents("http://www.geoplugin.net/json.gp?ip=".$ip));

                if($ip_data && $ip_data->geoplugin_countryName != null)
                {
                    $result = array('ip'=>$ip,
                                    'continentCode'=>$ip_data->geoplugin_continentCode,
                                    'countryCode'=>$ip_data->geoplugin_countryCode,
                                    'countryName'=>$ip_data->geoplugin_countryName,
                                    );
                }

                return $result;
            }


           $visitor_details= visitor_country(); // Output Country name [Ex: United States]
           $country=$visitor_details['countryName'];

You can't use PHP in the WordPress back-end Page editor. Maybe with a plugin you can, but not out of the box.

The easiest solution for this is creating a shortcode. Then you can use something like this

function input_func( $atts ) {
    extract( shortcode_atts( array(
        'type' => 'text',
        'name' => '',
    ), $atts ) );

    return '<input name="' . $name . '" id="' . $name . '" value="' . (isset($_GET\['from'\]) && $_GET\['from'\] ? $_GET\['from'\] : '') . '" type="' . $type . '" />';
}
add_shortcode( 'input', 'input_func' );

See the Shortcode_API.

When I was trying to accomplish something very similar, I ended up doing something along these lines:

wp-content/themes/resources/functions.php

add_action('init', 'my_php_function');
function my_php_function() {
    if (stripos($_SERVER['REQUEST_URI'], 'page-with-custom-php') !== false) {
        // add desired php code here
    }
}

Description:

there are 3 steps to run PHP code inside post or page.

1. In functions.php file (in your theme) add new function

2. In functions.php file (in your theme) register new shortcode which call your function:

add_shortcode( 'SHORCODE_NAME', 'FUNCTION_NAME' );

3. use your new shortcode

Example #1: just display text.

In functions:

function simple_function_1() {
    return "Hello World!";
}

add_shortcode( 'own_shortcode1', 'simple_function_1' );

In post/page:

[own_shortcode1]

Effect:

Hello World!

Example #2: use for loop.

In functions:

function simple_function_2() {
    $output = "";
    
    for ($number = 1; $number < 10; $number++) {    
        // Append numbers to the string
        $output .= "$number<br>";
    } 
    
    return "$output";
}

add_shortcode( 'own_shortcode2', 'simple_function_2' );

In post/page:

[own_shortcode2]

Effect:

1
2
3
4
5
6
7
8
9

Example #3: use shortcode with arguments

In functions:

function simple_function_3($name) {
    return "Hello $name";
}

add_shortcode( 'own_shortcode3', 'simple_function_3' );

In post/page:

[own_shortcode3 name="John"]

Effect:

Hello John

Example #3 - without passing arguments

In post/page:

[own_shortcode3]

Effect:

Hello