phpMyAdmin Error #2002 - Cannot Log in to the MySQL server.

When you see this error message, you properly do not config your php.ini well and so that it cannot connect to mysql server.

1. Wrong path for the mysql.sock
mysql.sock is the instance of the mysql, so first you have to find where does it place at.
You may find it at "/tmp/mysql.sock" or "/var/mysql/mysql.sock".

Go to your php.ini and make sure the value for "pdo_mysql.default_socket", "mysql.default_socket", "mysqli.default_socket" is the right path.

Then restart your web server and try again. Good Luck =]

How to add softlink in linux

command: ln -s <target> <the link>

example: ln -s /var/log /home/someone/log

Remarks:

<the link> should not exist, if <the link> exist, then remove it first.

Solution: You don't have permission to access / on this server

Encounter this problem after you set up virtual host in web server?
It is because the folder permission is not set probably.

Here is an example:


<Virtualhost *:80="">
ServerName testhost.com
DocumentRoot "/home/testhost/www"
DirectoryIndex index.php
<Directory "/home/testhost/www">
AllowOverride All
Allow from All
</Directory>


ErrorLog "logs/testhost-error.log"
CustomLog "logs/testhost-access.log" common
</Virtualhost>

Make sure to set permission 755 for each folder in the document root path
/home <- 755
/home/testhost <-- 755
/home/testhost/www <-- 755

Custom error500 / 400 page in symfony 1.4

Custom 400 page:

In config/settings.yml,
all:
  .actions:
    error_404_module:       error
    error_404_action:       404

Then when a page is not found, it will forward to "<your_domain>/error/404".

Custom 500 page:

1. Create "error" folder under "config"
2. create "error.html.php" under "config/error"

Solution: route has some missing mandatory parameters

This time I encountered an error in symfony, I set a new route and got this error.
The route is like this:

new_page:
  url: /new/page/:id
  param: {module: page, action: new}
  requirements:
    id: \d+

How to fix?
1. Add a default value.

new_page:

  url: /new/page/:id

  param: {module: page, action: new, id: 0}

  requirements:

    id: \d+

2. Check if you used any routing functions like url_for2() that missing the input parameter.

Solution - "Fatal error: Maximum execution time of 30 seconds exceeded"

There are two methods to solve this problem (Fatal error: Maximum execution time of 30 seconds exceeded).

Method 1:
Step 1 : Open php.ini
Step 2 : Modify the value of "max_execution_time" to a greater value say 600
Step 3: Restart Server
Done.

Method 2 (Recommended):
Add "set_limit_time(600)" in your code, where the input parameter is the max execution time, and 0 means unlimited.

Explanation:
You should be aware of this error message, because it should not take more than 30s to complete a script normally. Sometime, it may because of coding mistakes like (infinity loop in your code).

However, you may really need to execute heavy code in many cases, then I would recommend you to use the method 2 to solve this problem.

PHP Filter - email validation

For PHP5, you can validate email format as below:

$email = 'testemail@xxx.com';  
  
if( filter_var($email, FILTER_VALIDATE_EMAIL) )  
 echo 'Valid email format!';  
else  
 echo 'Invalid email format!'; 

For PHP version less than 5.0, you have to use regular expression to validate email format.

$email = 'testemail@xxx.com';  
  
if( eregi('^[A-Z0-9._%-]+@[A-Z0-9._%-]+\.[A-Z]{2,6}$', $email) ) 
 echo 'Valid email format!';  
else  
 echo 'Invalid email format!'; 

For reference:

You can found out more build-in validates at php.net each as URL, IP validation which are very useful.
http://php.net/manual/en/filter.filters.validate.php