centos + php5.4 + nginx 编译安装，连接mysql出错

      最近在centos 下 编译安装 nginx + php5.4 ，其中,mysql 通过yum 安装，后连接数据库错误

$id=mysql_connect("localhost","root","123456")or die(mysql_error());Fatal error: No such file or directory in /usr/local/nginx/html/

解决办法：打开php的error_log，观察错误日志

1. 修改php-fpm.conf中配置 没有则增加

catch_workers_output = yes
error_log = log/error_log

2. 修改php.ini中配置，没有则增加

log_errors = On
error_log = "/usr/local/lnmp/php/var/log/error.log"
error_reporting=E_ALL&~E_NOTICE

3. 重启php-fpm

当PHP执行错误时就能看到错误日志在"/usr/local/lnmp/php/var/log/error.log"中了

查看php 的error.log 报错信息如下：

[12-May-2014 16:38:22] WARNING: [pool www] child 6961 said into stderr: "NOTICE: PHP message: PHP Fatal error: No such file or directory in /usr/local/nginx/html/connections/conn.php on line 6"
[12-May-2014 16:40:08] WARNING: [pool www] child 6962 said into stderr: "NOTICE: PHP message: PHP Warning: mysql_connect(): No such file or directory in /usr/local/nginx/html/test.php on line 2"

但实际上文件是存在的，文件的第二行内容如下：

$id=mysql_connect("localhost","root","123456")or die(mysql_error());

查看mysql.sock文件的位置

root@node1:/var/mysql# vim /usr/local/mysql/my.cnf
socket = /usr/local/mysql/data/mysql.sock
root@node1:~# cd /var/
root@node1:/var# mkdir mysql
root@node1:/var# chmod 755 mysql
root@node1:~# cd /var/mysql/
root@node1:/var/mysql# ln -s /usr/local/mysql/data/mysql.sock mysql.sock
root@node1:/var/mysql# cd /tmp/
root@node1:/tmp# ln -s /usr/local/mysql/data/mysql.sock mysql.sock

显示结果正常：