有人知道为什么这个脚本在我尝试过的每台服务器上都能成功吗？尽管在头调用之前有早期输出，但我还是成功地重定向到了谷歌。
根据PHP文档，在输出后添加头失败并返回警告。然而，我在我的网络服务器上看到了不一致的行为。我一直在使用类似的方法来完成一些事情，除了一个随机停止工作的情况外，它运行得很好。
<?php
echo "lol";
?>
<html>
<?php
header("Location: http://www.google.com");
exit();
?>
那怎么回事？PHP的最新版本现在允许这样做吗？
我的php版本是Ubuntu 14.04 x64 上的php 5.5.9-1ubuntu4.14
Output_buffering已在我的服务器上启用，这允许进行一些设置：
; Output buffering is a mechanism for controlling how much output data
; (excluding headers and cookies) PHP should keep internally before pushing that
; data to the client. If your application's output exceeds this setting, PHP
; will send that data in chunks of roughly the size you specify.
; Turning on this setting and managing its maximum buffer size can yield some
; interesting side-effects depending on your application and web server.
; You may be able to send headers and cookies after you've already sent output
; through print or echo. You also may see performance benefits if your server is
; emitting less packets due to buffered output versus PHP streaming the output
; as it gets it. On production servers, 4096 bytes is a good setting for performance
; reasons.
; Note: Output buffering can also be controlled via Output Buffering Control
; functions.
; Possible Values:
; On = Enabled and buffer is unlimited. (Use with caution)
; Off = Disabled
; Integer = Enables the buffer and sets its maximum size in bytes.
; Note: This directive is hardcoded to Off for the CLI SAPI
; Default Value: Off
; Development Value: 4096
; Production Value: 4096
; http://php.net/output-buffering
output_buffering = 4096
啊，php。