getenv -- Gets the value of an environment variable
Returns the value of the environment variable varname, or FALSE on an error.
<span class="html"><span class="default"><font face="新宋体"><?php </FONT></font></span><font face="新宋体"><span class="comment">// Example use of getenv()</span><span class="default">$ip </span><span class="keyword">= </span><span class="default">getenv</span><span class="keyword">(</span><span class="string">'REMOTE_ADDR'</span></font><span class="keyword"><font face="新宋体">);<br></font></span><font face="新宋体"><span class="comment">// Or simply use a Superglobal ($_SERVER or $_ENV)</span><span class="default">$ip </span><span class="keyword">= </span><span class="default">$_SERVER</span><span class="keyword">[</span><span class="string">'REMOTE_ADDR'</span></font><font face="新宋体"><span class="keyword">];</span><span class="default">?></span> </font></span> |
这是在PHP官方的manual提供的方法。
但是当Web服务器API是ASAPI (IIS)的时候,getenv函数是不起作用的。这种情况下你如果用getenv来取得用户客户端ip的话,得到的将是错误的ip地址。
因此更为安全和准确的方法是尽量避免使用getenv函数。比如可以用以下的函数来获取ip信息:
//Get the real client IP ("bullet-proof")
function GetIP(){
if (getenv("HTTP_CLIENT_IP") && strcasecmp(getenv("HTTP_CLIENT_IP"), "unknown"))
$ip = getenv("HTTP_CLIENT_IP");
else if (getenv("HTTP_X_FORWARDED_FOR") && strcasecmp(getenv("HTTP_X_FORWARDED_FOR"), "unknown"))
$ip = getenv("HTTP_X_FORWARDED_FOR");
else if (getenv("REMOTE_ADDR") && strcasecmp(getenv("REMOTE_ADDR"), "unknown"))
$ip = getenv("REMOTE_ADDR");
else if (isset($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] && strcasecmp($_SERVER['REMOTE_ADDR'], "unknown"))
$ip = $_SERVER['REMOTE_ADDR'];
else
$ip = "unknown";
return($ip);
}