PHP主配置文件是/usr/local/php/etc/php.ini：

[root@centos6 ~]# /usr/local/php/bin/php -i |head

phpinfo()

PHP Version => 5.4.36

System => Linux centos6.5-1 2.6.32-431.el6.i686 #1 SMP Fri Nov 22 00:26:36 UTC 2013 i686

Build Date => Jan 14 2017 00:52:17

Configure Command =>  './configure'  '--prefix=/usr/local/php' '--with-apxs2=/usr/local/apache2/bin/apxs' '--with-config-file-path=/usr/local/php/etc' '--with-mysql=/usr/local/mysql' '--with-libxml-dir' '--with-gd' '--with-jpeg-dir' '--with-png-dir' '--with-freetype-dir' '--with-iconv-dir' '--with-zlib-dir' '--with-bz2' '--with-openssl' '--with-mcrypt' '--enable-soap' '--enable-gd-native-ttf' '--enable-mbstring' '--enable-sockets' '--enable-exif' '--disable-ipv6'

Server API => Command Line Interface

Virtual Directory Support => disabled

Configuration File (php.ini) Path => /usr/local/php/etc

Loaded Configuration File => /usr/local/php/etc/php.ini

该配置文件以分号“；”作为注释符号，可以使用参数 disable_functions 禁用一些高风险的函数：

[root@centos6 ~]# vim /usr/local/php/etc/php.ini

……

; This directive allows you to disable certain functions for security reasons.

; It receives a comma-delimited list of function names. This directive is

; *NOT* affected by whether Safe Mode is turned On or Off.

; http://php.net/disable-functions

disable_functions = eval,assert,popen,passthrn,escapeshllarg,escapes

hellcmd,passthru,exec,system,chroot,scandir,chgrp,chown,escapeshellc

md,escapeshellarg,shell_exec,proc_get_status,ini_alter,ini_restore,d

l,pfsockopen,openlog,syslog,readlink,syslink,leak,popepassthru,strea

m_socket_server,popen,proc_open,proc_close

可以打开display_errors=On（默认是Off)在浏览器中显示错误信息

;   On or stdout = Display errors to STDOUT

; Default Value: On

; Development Value: On

; Production Value: Off

; http://php.net/display-errors

display_errors = On

重新加载配置文件

[root@centos6 ~]# apachectl -t

Syntax OK

[root@centos6 ~]# apachectl graceful

打开我们论坛页面，人为加点错误

[root@centos6 ~]# vim /data/www/forum.php

abcdefgh #来点错误

/**

*      [Discuz!] (C)2001-2099 Comsenz Inc.

*      This is NOT a freeware, use is subject to license terms

*

*      $Id: forum.php 33828 2013-08-20 02:29:32Z nemohou $

*/

define('APPTYPEID', 2);

define('CURSCRIPT', 'forum');

……

访问会出现错误

display_errors = On改回默认值Off

[root@centos6 ~]#  vim /usr/local/php/etc/php.ini

……

;   On or stdout = Display errors to STDOUT

; Default Value: On

; Development Value: On

; Production Value: Off

; http://php.net/display-errors

display_errors = Off

……

[root@centos6 ~]# apachectl -t

Syntax OK

[root@centos6 ~]# apachectl graceful

访问不提示错误，空白，按F12查看状态码为500

也可以使用curl查看状态码

[root@centos6 ~]# curl -x192.168.147.132:80 www.test.com/forum.php -I

HTTP/1.0 500 Internal Server Error

Date: Sat, 14 Jan 2017 22:40:53 GMT

Server: Apache/2.2.9 (Unix) PHP/5.4.36

X-Powered-By: PHP/5.4.36

Cache-Control: max-age=0

Expires: Sat, 14 Jan 2017 22:40:53 GMT

Connection: close

Content-Type: text/html

我们不可以使用display_errors=On来再浏览器页面中查看我们的错误信息，因为这样会把错误暴露给所有用户，这很危险。我们使用log_errors=On（默认是打开的）来记录错误信息，以供改正。

只需要定义错误日志存放的位置

[root@centos6 ~]# mkdir /usr/local/php/logs

[root@centos6 ~]# chmod 777 !$

chmod 777 /usr/local/php/logs

定义存放位置：

; Example:

error_log = /usr/local/php/logs/php_errors.log

; Log errors to syslog (Event Log on Windows).

定义错误日志级别：

; Default Value: E_ALL & ~E_NOTICE & ~E_STRICT & ~E_DEPRECATED

; Development Value: E_ALL

; Production Value: E_ALL & ~E_DEPRECATED & ~E_STRICT

; http://php.net/error-reporting

error_reporting = E_ALL & ~E_NOTICE

重新加载配置文件后

[root@centos6 ~]# apachectl -t

Syntax OK

[root@centos6 ~]# apachectl graceful

刷新浏览器，会在我们指定的路径下生成一个错误日志，内容跟使用浏览器显示的错误一样：

[root@centos6 logs]# ls

php_errors.log

[root@centos6 logs]# cat php_errors.log

[14-Jan-2017 22:47:45 UTC] PHP Parse error:  syntax error, unexpected 'define' (T_STRING) in /data/www/forum.php on line 11

限制用户只能访问的目录，以：分割多个目录（这里我们去掉forum.php中的错误代码）

[root@centos6 logs]#  vim /usr/local/php/etc/php.ini

; open_basedir, if set, limits all file operations to the defined directory

; and below.  This directive makes most sense if used in a per-directory

; or per-virtualhost web server configuration file. This directive is

; *NOT* affected by whether Safe Mode is turned On or Off.

; http://php.net/open-basedir

open_basedir = /data/www/:/tmp/

[root@centos6 logs]# apachectl -t

Syntax OK

[root@centos6 logs]# apachectl graceful

如果我们限制用户到一个错误的目录比如www2（不存在）：

[root@centos6 logs]#  vim /usr/local/php/etc/php.ini

; open_basedir, if set, limits all file operations to the defined directory

; and below.  This directive makes most sense if used in a per-directory

; or per-virtualhost web server configuration file. This directive is

; *NOT* affected by whether Safe Mode is turned On or Off.

; http://php.net/open-basedir

open_basedir = /data/www2/:/tmp/

[root@centos6 logs]# apachectl -t

Syntax OK

[root@centos6 logs]# apachectl graceful

又不能访问了

从错误日志中找到原因

[root@centos6 logs]# cat php_errors.log

……

[14-Jan-2017 22:55:07 UTC] PHP Warning:  Unknown: open_basedir restriction in effect. File(/data/www/forum.php) is not within the allowed path(s): (/data/www2/:/tmp/) in Unknown on line 0

……

因此允许访问的目录范围一定要限制正确。

如果有多个虚拟主机，多个网站，就需要做多个open_basedir限制，如果使用php.ini配置的话，只能一组目录，多个站点无法指定自己特有的目录，所以我们使用虚拟主机配置文件做配置。

先把php.ini里的open_basedir注释掉

[root@centos6 logs]#  vim /usr/local/php/etc/php.ini

……

; open_basedir, if set, limits all file operations to the defined directory

; and below.  This directive makes most sense if used in a per-directory

; or per-virtualhost web server configuration file. This directive is

; *NOT* affected by whether Safe Mode is turned On or Off.

; http://php.net/open-basedir

;open_basedir = /data/www/:/tmp/

……

我们这里只有一台虚拟主机，在其中加入如下内容即可，如果有多台虚拟主机，每一台都可以指定自己的目录

[root@centos6 logs]# vim /usr/local/apache2/conf/extra/httpd-vhosts.conf

……

#    ServerAdmin webmaster@dummy-host2.example.com

DocumentRoot "/data/www"

ServerName www.test.com

ServerAlias www.aaa.com

ServerAlias www.bbb.com

 php_admin_value open_basedir "/data/www/:/tmp/"

AllowOverride None

Options None

……

[root@centos6 logs]# apachectl -t

Syntax OK

[root@centos6 logs]# apachectl graceful