Question

我收到以下错误：

Warning: session_start() [function.session-start]: Cannot send session cookie - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 3
Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 3
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 20
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 24
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 25
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 38
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 39
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 52
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 52
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 38
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 39
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 52
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 52
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 76
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 77
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 96
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 96
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 96
Warning: Cannot modify header information - headers already sent by (output started at C:\Apache2.2\htdocs\monitor.php:2) in C:\Apache2.2\htdocs\monitor.php on line 96

只要在session_start()和刷新cookie时就会出现。

同一页面（和代码）正在另一台机器上运行。唯一的区别是安装的Apache服务器（我的是2.2.21，另一个是2.2.17）。

php版本是5.2.17，php.ini文件是相同的。

我该如何解决这种情况？

Answer 1

大多数情况下，在调用session_start（）之前从php脚本发送内容/输出时会发生此错误。

通常在<?php之前，你可能有空格或其他标志/字母。在您的情况下，问题出在monitor.php第2行 - 您可能在调用session_start()

之前回调

Answer 2

~~php.ini文件是否相同？~~对我来说，听起来其中一个可能有output_buffering = on而另一个（失败的那个）有output_buffering = off。

http://www.php.net/manual/en/outcontrol.configuration.php

显然，默认情况取决于PHP的安装类型。

Answer 3

您应该检查文件monitor.php的第二行，因为此行似乎会向浏览器输出一些文字。

在输出文字后，您无法执行session_start()。

php页面出错

3 个答案: