(PHP 4 >= 4.0.1, PHP 5)
php_sapi_name — 返回 web 服务器和 PHP 之间的接口类型
返回描述 PHP 所使用的接口类型（the Server API, SAPI）的小写字符串。 例如，CLI 的 PHP 下这个字符串会是 "cli"，Apache 下可能会有几个不同的值，取决于具体使用的 SAPI。 以下列出了可能的值。
返回接口类型的小写字符串。
尽管不够全面，可能返回的值包括了 aolserver、apache、 apache2filter、apache2handler、 caudium、cgi （直到 PHP 5.3）, cgi-fcgi、cli、 continuity、embed、 isapi、litespeed、 milter、nsapi、 phttpd、pi3web、roxen、 thttpd、tux 和 webjames。
Example #1 php_sapi_name() 例子
以下例子检测了子字符串 cgi，因为它也有可能会是 cgi-fcgi。
<?php
$sapi_type = php_sapi_name();
if (substr($sapi_type, 0, 3) == 'cgi') {
echo "You are using CGI PHP\n";
} else {
echo "You are not using CGI PHP\n";
}
?>
Note: 另一种方法
PHP 常量
PHP_SAPI具有和 php_sapi_name() 相同的值。
定义的 SAPI 可能不够明显，比如它可能定义为 apache2handler 或 apache2filter，而不是 apache
sageptr at gmail dot com (2012-06-05 21:13:54)
Just another simple way to determine if script ran locally (php cli or wget), or by remote user:
<?php
if(isset($_SERVER["REMOTE_ADDR"]) && ($_SERVER["REMOTE_ADDR"] != $_SERVER["SERVER_ADDR"])){
exit('Permission denied');
};
// do something
?>
michal at roszka dot pl (2009-03-26 01:13:10)
The php_sapi_name() function is extremely useful when you want to determine the type of interface. There is, however, one more gotcha you need to be aware of while designing your application or deploying it to an unknown server.
Whenever something depends on the type of interface, make sure your check is conclusive. Especially when you want to distinguish the command line interface (CLI) from the common gateway interface (CGI).
Note, that the php-cgi binary can be called from the command line, from a shell script or as a cron job as well! If so, the php_sapi_name() will always return the same value (i.e. "cgi-fcgi") instead of "cli" which you could expect.
Bad things happen to good people. Do not always expect /usr/bin/php to be a link to php-cli binary.
Luckily the contents of the $_SERVER and the $_ENV superglobal arrays depends on whether the php-cgi binary is called from the command line interface (by a shell script, by the cron, etc.) or by some HTTP server (i.e. lighttpd).
<?php
var_dump($_SERVER);
?>
Try to call php-cgi binary from the command line interface and then via HTTP request and compare the output of the script above. There will be plenty options to satisfy almost everyone.
For the sake of security remember, that contents of the $_SERVER and the $_ENV superglobal arrays (as well as $_GET, $_POST, $_COOKIE, $_FILES and $_REQUEST) should be considered tainted.
Ysangkok (2008-08-27 14:34:37)
This function can also return "cli" if PHP was launched from CLI. Useful if one wants to behave differently when running in console.