simple contact form shortcode (for wp)

simple_contact.php

<?php 
/* 
Plugin Name: Simple Contact Form (Shortcode) 
Plugin URI: http://beyn.org/ 
Description: A simple contact form. Usage: [b_form email="send@form.here"]
Version: 0.1.1
Author: Barış Ünver 
Author URI: http://beyn.org/ 
*/ 

function get_real_ip() { 

    if ( isset($_SERVER) ){ 

        if ( isset($_SERVER['HTTP_X_FORWARDED_FOR']) ){
			$ip = $_SERVER['HTTP_X_FORWARDED_FOR'];
		}elseif ( isset($_SERVER['HTTP_CLIENT_IP']) ){
			$ip = $_SERVER['HTTP_CLIENT_IP'];
		}else{
			$ip = $_SERVER['REMOTE_ADDR'];
		}
		 
    }else{
 
        if ( getenv('HTTP_X_FORWARDED_FOR') ){
			$ip = getenv('HTTP_X_FORWARDED_FOR');
		} 
        elseif ( getenv('HTTP_CLIENT_IP') ){
			$ip = getenv('HTTP_CLIENT_IP');
		}else{
			$ip = getenv('REMOTE_ADDR');
		}
		 
    } 
    return $ip;
 
} 

function contact_form($atts) { 
    extract(shortcode_atts(array( 
        "eposta" => '', 
        "konu" => '' 
    ), $atts)); 
    $ip_adresi = get_real_ip(); 
    $req_fields = array("ifoisim", "ifoeposta", "ifomesaj", "ifokonu"); 

    if (isset($_POST['ifogonder']) && trim($_POST['ifogonder']) != "") { 
         function has_newlines($text) { return preg_match("/(%0A|%0D|\n+|\r+)/i", $text); } 
         function has_emailheaders($text) { return preg_match("/(%0A|%0D|\n+|\r+)(content-type:|to:|cc:|bcc:)/i", $text); } 
         function is_valid($text) { return preg_match("/^([a-z0-9\+_\-]+)(\.[a-z0-9\+_\-]+)*@([a-z0-9\-]+\.)+[a-z]{2,6}$/ix", $text); } 
         foreach ($_POST AS $key => $value) { 
            if (get_magic_quotes_gpc()) { $value = stripslashes($value); } 
            $form_verisi[$key] = strip_tags($value); 
        } 

        $formerror = FALSE; 
        foreach ($req_fields AS $formlabel) { 
            $value = trim($form_verisi[$formlabel]); 
            if (empty($value)) { $formerror = TRUE; } 
        } 

        if (!$formerror) { 
            $error_msg = ""; 
            if (empty($error_msg)) { 
                $eposta_metni = $form_verisi['ifomesaj']; 
                $eposta_metni .= "\n\nIP: ". $ip_adresi; 
                $headers = "From: ".$form_verisi['ifoisim']." <".$form_verisi['ifoeposta'].">\n"; 
                $headers .= "Mime-Version: 1.0\n"; 
                $headers .= "Content-Type: text/plain; charset=UTF-8\n"; 
                $headers .= "Reply-To: ".$form_verisi['ifoisim']." <".$form_verisi['ifoeposta'].">\n"; 
                $headers .= "Organization: Beyn.org iletisim formu\n"; 
                $headers .= "Content-Transfer-Encoding: 8bit\n"; 
                $headers .= "Return-Path: ".$form_verisi['ifoisim']." <".$form_verisi['ifoeposta'].">\n"; 
                $headers .= "Errors-To: ".$eposta; 
                $eposta_konusu = "[Beyn] " . $form_verisi['ifokonu']; 
                if(!preg_match("/\[url/",$eposta_metni)) {mail($eposta, $eposta_konusu, $eposta_metni, $headers);} 
                $error_msg = "<div style=\"text-align:center;font-size:20px;color:#080;\">Mesajınız için teşekkürler!</div>\n"; 
            } 
        } else { $error_msg = "Lütfen tüm alanları doldurun.\n"; } 
    } 

    function get_value($formvalue) { 
        if (!empty($_POST[$formvalue])) { 
            if (get_magic_quotes_gpc()) { $form_value = stripslashes($_POST[$formvalue]);} else { $form_value = $_POST[$formvalue]; } 
        } 
        return $form_value; 
    } 
    $ifoisim_girilen = get_value('ifoisim'); 
    $ifoeposta_girilen = get_value('ifoeposta'); 
    $ifokonu_girilen = get_value('ifokonu'); 

    if (!empty($error_msg)) { $mesaj_cikti = "\n<div class=\"ifohata\">\n" .$error_msg. "</div>\n"; }     

    $cikti = ' 
    <style type="text/css"> 
    form.iletisim-formu {margin-top:15px;} 
    form.iletisim-formu div {clear:both;margin-bottom:10px;width:500px;} 
    form.iletisim-formu div label {width:200px;float:left;text-align:right;margin-right:5px;} 
    form.iletisim-formu div.ifohata {color:#c00;font-weight:bold;} 
    form.iletisim-formu #ifogonder {margin-top:5px;padding:0 10px;} 
    </style> 
    <form class="iletisim-formu" method="post">' . $mesaj_cikti . ' 
        <div> 
            <label for="ifoisim">Adınız:</label> 
            <input type="text" name="ifoisim" id="ifoisim" size="30" maxlength="50" value="' . $ifoisim_girilen . '" /> 
        </div>     
        <div> 
            <label for="ifoeposta">E-posta adresiniz:</label> 
            <input type="text" name="ifoeposta" id="ifoeposta" size="30" maxlength="50" value="' . $ifoeposta_girilen . '" /> 
        </div>     
        <div> 
            <label for="ifokonu">E-posta başlığı:</label> 
            <input type="text" name="ifokonu" id="ifokonu" size="30" maxlength="50" value="' . $konu . $ifokonu_girilen . '" /> 
        </div>     
        <div> 
            <label for="ifomesaj">Mesajınız:</label> 
            <textarea name="ifomesaj" id="ifomesaj" cols="30" rows="8">' . $ifomesaj_girilen . '</textarea><br /> 
            <label>&nbsp;</label> 
            <input type="submit" value="Gönder" name="ifogonder" id="ifogonder" /> 
        </div> 
    </form>'; 
    return $cikti; 
} 

add_shortcode('b_form', 'contact_form'); 

/* Kaynak: http://www.stuffbysarah.net/2008/03/19/secure-php-contact-form/ */